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    SubjectRe: [PATCH] mm: kill kmemcheck again
    On 30 September 2017 at 11:48, Steven Rostedt <rostedt@goodmis.org> wrote:
    > On Wed, 27 Sep 2017 17:02:07 +0200
    > Michal Hocko <mhocko@kernel.org> wrote:
    >
    >> > Now that 2 years have passed, and all distros provide gcc that supports
    >> > KASAN, kill kmemcheck again for the very same reasons.
    >>
    >> This is just too large to review manually. How have you generated the
    >> patch?
    >
    > I agree. This needs to be taken out piece by piece, not in one go,
    > where there could be unexpected fallout.

    I have a patch from earlier this year that starts by removing the core
    code and defining all the helpers/flags as no-ops so they can be
    removed bit by bit at a later time. See the attachment. Pekka signed
    off on it too.

    I never actually submitted this because I was waiting for MSAN to be
    merged in the kernel. It has been compile and run tested on x86_64.


    Vegard
    From b06e2b3b833b02ecb0afb9dd92422e89c7fbb6d9 Mon Sep 17 00:00:00 2001
    From: Vegard Nossum <vegard.nossum@oracle.com>
    Date: Thu, 30 Mar 2017 13:26:15 +0200
    Subject: [PATCH] kmemcheck: remove core (x86 + mm) code

    With KASAN/KMSAN and compiler-based instrumentation, this code is way past
    its expiry date. There is zero reason to be using kmemcheck at this point,
    as KASAN/KMSAN will be much faster, support SMP, and catch any bug that
    kmemcheck would have caught. See the additional rationale and past
    discussion at <https://lkml.org/lkml/2015/3/11/435>.

    I take the approach of first removing all the core x86 and mm code, leaving
    behind only include/linux/kmemcheck.h which provides some helpers (now only
    dummies as for the !KMEMCHECK case previously) used in e.g. networking code
    for special annotations.

    We can then send individual (smaller, more reviewable) patches for removing
    kmemcheck annotations in other subsystems.

    Once there are no users of the kmemcheck helpers, we can kill off the dummy
    helpers as well in a final patch.

    Cc: Ingo Molnar <mingo@kernel.org>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Sasha Levin <alexander.levin@verizon.com>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
    Signed-off-by: Pekka Enberg <penberg@kernel.org>
    ---
    Documentation/admin-guide/kernel-parameters.txt | 7 -
    Documentation/dev-tools/index.rst | 1 -
    Documentation/dev-tools/kmemcheck.rst | 733 ------------------------
    MAINTAINERS | 10 -
    arch/arm/include/asm/dma-iommu.h | 1 -
    arch/openrisc/include/asm/dma-mapping.h | 1 -
    arch/x86/Kconfig | 3 +-
    arch/x86/Makefile | 5 -
    arch/x86/include/asm/dma-mapping.h | 1 -
    arch/x86/include/asm/kmemcheck.h | 42 --
    arch/x86/include/asm/pgtable_types.h | 8 +-
    arch/x86/include/asm/string_32.h | 9 -
    arch/x86/include/asm/string_64.h | 8 -
    arch/x86/include/asm/xor.h | 5 +-
    arch/x86/kernel/cpu/intel.c | 15 -
    arch/x86/kernel/traps.c | 5 -
    arch/x86/mm/Makefile | 2 -
    arch/x86/mm/fault.c | 6 -
    arch/x86/mm/init.c | 5 +-
    arch/x86/mm/kmemcheck/Makefile | 1 -
    arch/x86/mm/kmemcheck/error.c | 227 --------
    arch/x86/mm/kmemcheck/error.h | 15 -
    arch/x86/mm/kmemcheck/kmemcheck.c | 658 ---------------------
    arch/x86/mm/kmemcheck/opcode.c | 106 ----
    arch/x86/mm/kmemcheck/opcode.h | 9 -
    arch/x86/mm/kmemcheck/pte.c | 22 -
    arch/x86/mm/kmemcheck/pte.h | 10 -
    arch/x86/mm/kmemcheck/selftest.c | 70 ---
    arch/x86/mm/kmemcheck/selftest.h | 6 -
    arch/x86/mm/kmemcheck/shadow.c | 173 ------
    arch/x86/mm/kmemcheck/shadow.h | 18 -
    include/linux/dma-mapping.h | 8 +-
    include/linux/gfp.h | 2 -
    include/linux/kmemcheck.h | 59 --
    include/linux/mm_types.h | 8 -
    include/linux/slab.h | 12 +-
    init/main.c | 1 -
    kernel/sysctl.c | 10 -
    lib/Kconfig.debug | 6 +-
    lib/Kconfig.kmemcheck | 94 ---
    mm/Kconfig.debug | 1 -
    mm/Makefile | 2 -
    mm/kmemcheck.c | 125 ----
    mm/page_alloc.c | 14 -
    mm/slab.c | 14 -
    mm/slab.h | 2 -
    mm/slub.c | 25 +-
    47 files changed, 18 insertions(+), 2547 deletions(-)
    delete mode 100644 Documentation/dev-tools/kmemcheck.rst
    delete mode 100644 arch/x86/include/asm/kmemcheck.h
    delete mode 100644 arch/x86/mm/kmemcheck/Makefile
    delete mode 100644 arch/x86/mm/kmemcheck/error.c
    delete mode 100644 arch/x86/mm/kmemcheck/error.h
    delete mode 100644 arch/x86/mm/kmemcheck/kmemcheck.c
    delete mode 100644 arch/x86/mm/kmemcheck/opcode.c
    delete mode 100644 arch/x86/mm/kmemcheck/opcode.h
    delete mode 100644 arch/x86/mm/kmemcheck/pte.c
    delete mode 100644 arch/x86/mm/kmemcheck/pte.h
    delete mode 100644 arch/x86/mm/kmemcheck/selftest.c
    delete mode 100644 arch/x86/mm/kmemcheck/selftest.h
    delete mode 100644 arch/x86/mm/kmemcheck/shadow.c
    delete mode 100644 arch/x86/mm/kmemcheck/shadow.h
    delete mode 100644 lib/Kconfig.kmemcheck
    delete mode 100644 mm/kmemcheck.c

    diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
    index facc20a3f962..c3a1a7edfcfc 100644
    --- a/Documentation/admin-guide/kernel-parameters.txt
    +++ b/Documentation/admin-guide/kernel-parameters.txt
    @@ -1793,13 +1793,6 @@
    Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y,
    the default is off.

    - kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode
    - Valid arguments: 0, 1, 2
    - kmemcheck=0 (disabled)
    - kmemcheck=1 (enabled)
    - kmemcheck=2 (one-shot mode)
    - Default: 2 (one-shot mode)
    -
    kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
    Default is 0 (don't ignore, but inject #GP)

    diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst
    index 07d881147ef3..0196fcf8a7a5 100644
    --- a/Documentation/dev-tools/index.rst
    +++ b/Documentation/dev-tools/index.rst
    @@ -21,7 +21,6 @@ whole; patches welcome!
    kasan
    ubsan
    kmemleak
    - kmemcheck
    gdb-kernel-debugging


    diff --git a/Documentation/dev-tools/kmemcheck.rst b/Documentation/dev-tools/kmemcheck.rst
    deleted file mode 100644
    index 7f3d1985de74..000000000000
    --- a/Documentation/dev-tools/kmemcheck.rst
    +++ /dev/null
    @@ -1,733 +0,0 @@
    -Getting started with kmemcheck
    -==============================
    -
    -Vegard Nossum <vegardno@ifi.uio.no>
    -
    -
    -Introduction
    -------------
    -
    -kmemcheck is a debugging feature for the Linux Kernel. More specifically, it
    -is a dynamic checker that detects and warns about some uses of uninitialized
    -memory.
    -
    -Userspace programmers might be familiar with Valgrind's memcheck. The main
    -difference between memcheck and kmemcheck is that memcheck works for userspace
    -programs only, and kmemcheck works for the kernel only. The implementations
    -are of course vastly different. Because of this, kmemcheck is not as accurate
    -as memcheck, but it turns out to be good enough in practice to discover real
    -programmer errors that the compiler is not able to find through static
    -analysis.
    -
    -Enabling kmemcheck on a kernel will probably slow it down to the extent that
    -the machine will not be usable for normal workloads such as e.g. an
    -interactive desktop. kmemcheck will also cause the kernel to use about twice
    -as much memory as normal. For this reason, kmemcheck is strictly a debugging
    -feature.
    -
    -
    -Downloading
    ------------
    -
    -As of version 2.6.31-rc1, kmemcheck is included in the mainline kernel.
    -
    -
    -Configuring and compiling
    --------------------------
    -
    -kmemcheck only works for the x86 (both 32- and 64-bit) platform. A number of
    -configuration variables must have specific settings in order for the kmemcheck
    -menu to even appear in "menuconfig". These are:
    -
    -- ``CONFIG_CC_OPTIMIZE_FOR_SIZE=n``
    - This option is located under "General setup" / "Optimize for size".
    -
    - Without this, gcc will use certain optimizations that usually lead to
    - false positive warnings from kmemcheck. An example of this is a 16-bit
    - field in a struct, where gcc may load 32 bits, then discard the upper
    - 16 bits. kmemcheck sees only the 32-bit load, and may trigger a
    - warning for the upper 16 bits (if they're uninitialized).
    -
    -- ``CONFIG_SLAB=y`` or ``CONFIG_SLUB=y``
    - This option is located under "General setup" / "Choose SLAB
    - allocator".
    -
    -- ``CONFIG_FUNCTION_TRACER=n``
    - This option is located under "Kernel hacking" / "Tracers" / "Kernel
    - Function Tracer"
    -
    - When function tracing is compiled in, gcc emits a call to another
    - function at the beginning of every function. This means that when the
    - page fault handler is called, the ftrace framework will be called
    - before kmemcheck has had a chance to handle the fault. If ftrace then
    - modifies memory that was tracked by kmemcheck, the result is an
    - endless recursive page fault.
    -
    -- ``CONFIG_DEBUG_PAGEALLOC=n``
    - This option is located under "Kernel hacking" / "Memory Debugging"
    - / "Debug page memory allocations".
    -
    -In addition, I highly recommend turning on ``CONFIG_DEBUG_INFO=y``. This is also
    -located under "Kernel hacking". With this, you will be able to get line number
    -information from the kmemcheck warnings, which is extremely valuable in
    -debugging a problem. This option is not mandatory, however, because it slows
    -down the compilation process and produces a much bigger kernel image.
    -
    -Now the kmemcheck menu should be visible (under "Kernel hacking" / "Memory
    -Debugging" / "kmemcheck: trap use of uninitialized memory"). Here follows
    -a description of the kmemcheck configuration variables:
    -
    -- ``CONFIG_KMEMCHECK``
    - This must be enabled in order to use kmemcheck at all...
    -
    -- ``CONFIG_KMEMCHECK_``[``DISABLED`` | ``ENABLED`` | ``ONESHOT``]``_BY_DEFAULT``
    - This option controls the status of kmemcheck at boot-time. "Enabled"
    - will enable kmemcheck right from the start, "disabled" will boot the
    - kernel as normal (but with the kmemcheck code compiled in, so it can
    - be enabled at run-time after the kernel has booted), and "one-shot" is
    - a special mode which will turn kmemcheck off automatically after
    - detecting the first use of uninitialized memory.
    -
    - If you are using kmemcheck to actively debug a problem, then you
    - probably want to choose "enabled" here.
    -
    - The one-shot mode is mostly useful in automated test setups because it
    - can prevent floods of warnings and increase the chances of the machine
    - surviving in case something is really wrong. In other cases, the one-
    - shot mode could actually be counter-productive because it would turn
    - itself off at the very first error -- in the case of a false positive
    - too -- and this would come in the way of debugging the specific
    - problem you were interested in.
    -
    - If you would like to use your kernel as normal, but with a chance to
    - enable kmemcheck in case of some problem, it might be a good idea to
    - choose "disabled" here. When kmemcheck is disabled, most of the run-
    - time overhead is not incurred, and the kernel will be almost as fast
    - as normal.
    -
    -- ``CONFIG_KMEMCHECK_QUEUE_SIZE``
    - Select the maximum number of error reports to store in an internal
    - (fixed-size) buffer. Since errors can occur virtually anywhere and in
    - any context, we need a temporary storage area which is guaranteed not
    - to generate any other page faults when accessed. The queue will be
    - emptied as soon as a tasklet may be scheduled. If the queue is full,
    - new error reports will be lost.
    -
    - The default value of 64 is probably fine. If some code produces more
    - than 64 errors within an irqs-off section, then the code is likely to
    - produce many, many more, too, and these additional reports seldom give
    - any more information (the first report is usually the most valuable
    - anyway).
    -
    - This number might have to be adjusted if you are not using serial
    - console or similar to capture the kernel log. If you are using the
    - "dmesg" command to save the log, then getting a lot of kmemcheck
    - warnings might overflow the kernel log itself, and the earlier reports
    - will get lost in that way instead. Try setting this to 10 or so on
    - such a setup.
    -
    -- ``CONFIG_KMEMCHECK_SHADOW_COPY_SHIFT``
    - Select the number of shadow bytes to save along with each entry of the
    - error-report queue. These bytes indicate what parts of an allocation
    - are initialized, uninitialized, etc. and will be displayed when an
    - error is detected to help the debugging of a particular problem.
    -
    - The number entered here is actually the logarithm of the number of
    - bytes that will be saved. So if you pick for example 5 here, kmemcheck
    - will save 2^5 = 32 bytes.
    -
    - The default value should be fine for debugging most problems. It also
    - fits nicely within 80 columns.
    -
    -- ``CONFIG_KMEMCHECK_PARTIAL_OK``
    - This option (when enabled) works around certain GCC optimizations that
    - produce 32-bit reads from 16-bit variables where the upper 16 bits are
    - thrown away afterwards.
    -
    - The default value (enabled) is recommended. This may of course hide
    - some real errors, but disabling it would probably produce a lot of
    - false positives.
    -
    -- ``CONFIG_KMEMCHECK_BITOPS_OK``
    - This option silences warnings that would be generated for bit-field
    - accesses where not all the bits are initialized at the same time. This
    - may also hide some real bugs.
    -
    - This option is probably obsolete, or it should be replaced with
    - the kmemcheck-/bitfield-annotations for the code in question. The
    - default value is therefore fine.
    -
    -Now compile the kernel as usual.
    -
    -
    -How to use
    -----------
    -
    -Booting
    -~~~~~~~
    -
    -First some information about the command-line options. There is only one
    -option specific to kmemcheck, and this is called "kmemcheck". It can be used
    -to override the default mode as chosen by the ``CONFIG_KMEMCHECK_*_BY_DEFAULT``
    -option. Its possible settings are:
    -
    -- ``kmemcheck=0`` (disabled)
    -- ``kmemcheck=1`` (enabled)
    -- ``kmemcheck=2`` (one-shot mode)
    -
    -If SLUB debugging has been enabled in the kernel, it may take precedence over
    -kmemcheck in such a way that the slab caches which are under SLUB debugging
    -will not be tracked by kmemcheck. In order to ensure that this doesn't happen
    -(even though it shouldn't by default), use SLUB's boot option ``slub_debug``,
    -like this: ``slub_debug=-``
    -
    -In fact, this option may also be used for fine-grained control over SLUB vs.
    -kmemcheck. For example, if the command line includes
    -``kmemcheck=1 slub_debug=,dentry``, then SLUB debugging will be used only
    -for the "dentry" slab cache, and with kmemcheck tracking all the other
    -caches. This is advanced usage, however, and is not generally recommended.
    -
    -
    -Run-time enable/disable
    -~~~~~~~~~~~~~~~~~~~~~~~
    -
    -When the kernel has booted, it is possible to enable or disable kmemcheck at
    -run-time. WARNING: This feature is still experimental and may cause false
    -positive warnings to appear. Therefore, try not to use this. If you find that
    -it doesn't work properly (e.g. you see an unreasonable amount of warnings), I
    -will be happy to take bug reports.
    -
    -Use the file ``/proc/sys/kernel/kmemcheck`` for this purpose, e.g.::
    -
    - $ echo 0 > /proc/sys/kernel/kmemcheck # disables kmemcheck
    -
    -The numbers are the same as for the ``kmemcheck=`` command-line option.
    -
    -
    -Debugging
    -~~~~~~~~~
    -
    -A typical report will look something like this::
    -
    - WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff88003e4a2024)
    - 80000000000000000000000000000000000000000088ffff0000000000000000
    - i i i i u u u u i i i i i i i i u u u u u u u u u u u u u u u u
    - ^
    -
    - Pid: 1856, comm: ntpdate Not tainted 2.6.29-rc5 #264 945P-A
    - RIP: 0010:[<ffffffff8104ede8>] [<ffffffff8104ede8>] __dequeue_signal+0xc8/0x190
    - RSP: 0018:ffff88003cdf7d98 EFLAGS: 00210002
    - RAX: 0000000000000030 RBX: ffff88003d4ea968 RCX: 0000000000000009
    - RDX: ffff88003e5d6018 RSI: ffff88003e5d6024 RDI: ffff88003cdf7e84
    - RBP: ffff88003cdf7db8 R08: ffff88003e5d6000 R09: 0000000000000000
    - R10: 0000000000000080 R11: 0000000000000000 R12: 000000000000000e
    - R13: ffff88003cdf7e78 R14: ffff88003d530710 R15: ffff88003d5a98c8
    - FS: 0000000000000000(0000) GS:ffff880001982000(0063) knlGS:00000
    - CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
    - CR2: ffff88003f806ea0 CR3: 000000003c036000 CR4: 00000000000006a0
    - DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    - DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
    - [<ffffffff8104f04e>] dequeue_signal+0x8e/0x170
    - [<ffffffff81050bd8>] get_signal_to_deliver+0x98/0x390
    - [<ffffffff8100b87d>] do_notify_resume+0xad/0x7d0
    - [<ffffffff8100c7b5>] int_signal+0x12/0x17
    - [<ffffffffffffffff>] 0xffffffffffffffff
    -
    -The single most valuable information in this report is the RIP (or EIP on 32-
    -bit) value. This will help us pinpoint exactly which instruction that caused
    -the warning.
    -
    -If your kernel was compiled with ``CONFIG_DEBUG_INFO=y``, then all we have to do
    -is give this address to the addr2line program, like this::
    -
    - $ addr2line -e vmlinux -i ffffffff8104ede8
    - arch/x86/include/asm/string_64.h:12
    - include/asm-generic/siginfo.h:287
    - kernel/signal.c:380
    - kernel/signal.c:410
    -
    -The "``-e vmlinux``" tells addr2line which file to look in. **IMPORTANT:**
    -This must be the vmlinux of the kernel that produced the warning in the
    -first place! If not, the line number information will almost certainly be
    -wrong.
    -
    -The "``-i``" tells addr2line to also print the line numbers of inlined
    -functions. In this case, the flag was very important, because otherwise,
    -it would only have printed the first line, which is just a call to
    -``memcpy()``, which could be called from a thousand places in the kernel, and
    -is therefore not very useful. These inlined functions would not show up in
    -the stack trace above, simply because the kernel doesn't load the extra
    -debugging information. This technique can of course be used with ordinary
    -kernel oopses as well.
    -
    -In this case, it's the caller of ``memcpy()`` that is interesting, and it can be
    -found in ``include/asm-generic/siginfo.h``, line 287::
    -
    - 281 static inline void copy_siginfo(struct siginfo *to, struct siginfo *from)
    - 282 {
    - 283 if (from->si_code < 0)
    - 284 memcpy(to, from, sizeof(*to));
    - 285 else
    - 286 /* _sigchld is currently the largest know union member */
    - 287 memcpy(to, from, __ARCH_SI_PREAMBLE_SIZE + sizeof(from->_sifields._sigchld));
    - 288 }
    -
    -Since this was a read (kmemcheck usually warns about reads only, though it can
    -warn about writes to unallocated or freed memory as well), it was probably the
    -"from" argument which contained some uninitialized bytes. Following the chain
    -of calls, we move upwards to see where "from" was allocated or initialized,
    -``kernel/signal.c``, line 380::
    -
    - 359 static void collect_signal(int sig, struct sigpending *list, siginfo_t *info)
    - 360 {
    - ...
    - 367 list_for_each_entry(q, &list->list, list) {
    - 368 if (q->info.si_signo == sig) {
    - 369 if (first)
    - 370 goto still_pending;
    - 371 first = q;
    - ...
    - 377 if (first) {
    - 378 still_pending:
    - 379 list_del_init(&first->list);
    - 380 copy_siginfo(info, &first->info);
    - 381 __sigqueue_free(first);
    - ...
    - 392 }
    - 393 }
    -
    -Here, it is ``&first->info`` that is being passed on to ``copy_siginfo()``. The
    -variable ``first`` was found on a list -- passed in as the second argument to
    -``collect_signal()``. We continue our journey through the stack, to figure out
    -where the item on "list" was allocated or initialized. We move to line 410::
    -
    - 395 static int __dequeue_signal(struct sigpending *pending, sigset_t *mask,
    - 396 siginfo_t *info)
    - 397 {
    - ...
    - 410 collect_signal(sig, pending, info);
    - ...
    - 414 }
    -
    -Now we need to follow the ``pending`` pointer, since that is being passed on to
    -``collect_signal()`` as ``list``. At this point, we've run out of lines from the
    -"addr2line" output. Not to worry, we just paste the next addresses from the
    -kmemcheck stack dump, i.e.::
    -
    - [<ffffffff8104f04e>] dequeue_signal+0x8e/0x170
    - [<ffffffff81050bd8>] get_signal_to_deliver+0x98/0x390
    - [<ffffffff8100b87d>] do_notify_resume+0xad/0x7d0
    - [<ffffffff8100c7b5>] int_signal+0x12/0x17
    -
    - $ addr2line -e vmlinux -i ffffffff8104f04e ffffffff81050bd8 \
    - ffffffff8100b87d ffffffff8100c7b5
    - kernel/signal.c:446
    - kernel/signal.c:1806
    - arch/x86/kernel/signal.c:805
    - arch/x86/kernel/signal.c:871
    - arch/x86/kernel/entry_64.S:694
    -
    -Remember that since these addresses were found on the stack and not as the
    -RIP value, they actually point to the _next_ instruction (they are return
    -addresses). This becomes obvious when we look at the code for line 446::
    -
    - 422 int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
    - 423 {
    - ...
    - 431 signr = __dequeue_signal(&tsk->signal->shared_pending,
    - 432 mask, info);
    - 433 /*
    - 434 * itimer signal ?
    - 435 *
    - 436 * itimers are process shared and we restart periodic
    - 437 * itimers in the signal delivery path to prevent DoS
    - 438 * attacks in the high resolution timer case. This is
    - 439 * compliant with the old way of self restarting
    - 440 * itimers, as the SIGALRM is a legacy signal and only
    - 441 * queued once. Changing the restart behaviour to
    - 442 * restart the timer in the signal dequeue path is
    - 443 * reducing the timer noise on heavy loaded !highres
    - 444 * systems too.
    - 445 */
    - 446 if (unlikely(signr == SIGALRM)) {
    - ...
    - 489 }
    -
    -So instead of looking at 446, we should be looking at 431, which is the line
    -that executes just before 446. Here we see that what we are looking for is
    -``&tsk->signal->shared_pending``.
    -
    -Our next task is now to figure out which function that puts items on this
    -``shared_pending`` list. A crude, but efficient tool, is ``git grep``::
    -
    - $ git grep -n 'shared_pending' kernel/
    - ...
    - kernel/signal.c:828: pending = group ? &t->signal->shared_pending : &t->pending;
    - kernel/signal.c:1339: pending = group ? &t->signal->shared_pending : &t->pending;
    - ...
    -
    -There were more results, but none of them were related to list operations,
    -and these were the only assignments. We inspect the line numbers more closely
    -and find that this is indeed where items are being added to the list::
    -
    - 816 static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
    - 817 int group)
    - 818 {
    - ...
    - 828 pending = group ? &t->signal->shared_pending : &t->pending;
    - ...
    - 851 q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN &&
    - 852 (is_si_special(info) ||
    - 853 info->si_code >= 0)));
    - 854 if (q) {
    - 855 list_add_tail(&q->list, &pending->list);
    - ...
    - 890 }
    -
    -and::
    -
    - 1309 int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
    - 1310 {
    - ....
    - 1339 pending = group ? &t->signal->shared_pending : &t->pending;
    - 1340 list_add_tail(&q->list, &pending->list);
    - ....
    - 1347 }
    -
    -In the first case, the list element we are looking for, ``q``, is being
    -returned from the function ``__sigqueue_alloc()``, which looks like an
    -allocation function. Let's take a look at it::
    -
    - 187 static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags,
    - 188 int override_rlimit)
    - 189 {
    - 190 struct sigqueue *q = NULL;
    - 191 struct user_struct *user;
    - 192
    - 193 /*
    - 194 * We won't get problems with the target's UID changing under us
    - 195 * because changing it requires RCU be used, and if t != current, the
    - 196 * caller must be holding the RCU readlock (by way of a spinlock) and
    - 197 * we use RCU protection here
    - 198 */
    - 199 user = get_uid(__task_cred(t)->user);
    - 200 atomic_inc(&user->sigpending);
    - 201 if (override_rlimit ||
    - 202 atomic_read(&user->sigpending) <=
    - 203 t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur)
    - 204 q = kmem_cache_alloc(sigqueue_cachep, flags);
    - 205 if (unlikely(q == NULL)) {
    - 206 atomic_dec(&user->sigpending);
    - 207 free_uid(user);
    - 208 } else {
    - 209 INIT_LIST_HEAD(&q->list);
    - 210 q->flags = 0;
    - 211 q->user = user;
    - 212 }
    - 213
    - 214 return q;
    - 215 }
    -
    -We see that this function initializes ``q->list``, ``q->flags``, and
    -``q->user``. It seems that now is the time to look at the definition of
    -``struct sigqueue``, e.g.::
    -
    - 14 struct sigqueue {
    - 15 struct list_head list;
    - 16 int flags;
    - 17 siginfo_t info;
    - 18 struct user_struct *user;
    - 19 };
    -
    -And, you might remember, it was a ``memcpy()`` on ``&first->info`` that
    -caused the warning, so this makes perfect sense. It also seems reasonable
    -to assume that it is the caller of ``__sigqueue_alloc()`` that has the
    -responsibility of filling out (initializing) this member.
    -
    -But just which fields of the struct were uninitialized? Let's look at
    -kmemcheck's report again::
    -
    - WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff88003e4a2024)
    - 80000000000000000000000000000000000000000088ffff0000000000000000
    - i i i i u u u u i i i i i i i i u u u u u u u u u u u u u u u u
    - ^
    -
    -These first two lines are the memory dump of the memory object itself, and
    -the shadow bytemap, respectively. The memory object itself is in this case
    -``&first->info``. Just beware that the start of this dump is NOT the start
    -of the object itself! The position of the caret (^) corresponds with the
    -address of the read (ffff88003e4a2024).
    -
    -The shadow bytemap dump legend is as follows:
    -
    -- i: initialized
    -- u: uninitialized
    -- a: unallocated (memory has been allocated by the slab layer, but has not
    - yet been handed off to anybody)
    -- f: freed (memory has been allocated by the slab layer, but has been freed
    - by the previous owner)
    -
    -In order to figure out where (relative to the start of the object) the
    -uninitialized memory was located, we have to look at the disassembly. For
    -that, we'll need the RIP address again::
    -
    - RIP: 0010:[<ffffffff8104ede8>] [<ffffffff8104ede8>] __dequeue_signal+0xc8/0x190
    -
    - $ objdump -d --no-show-raw-insn vmlinux | grep -C 8 ffffffff8104ede8:
    - ffffffff8104edc8: mov %r8,0x8(%r8)
    - ffffffff8104edcc: test %r10d,%r10d
    - ffffffff8104edcf: js ffffffff8104ee88 <__dequeue_signal+0x168>
    - ffffffff8104edd5: mov %rax,%rdx
    - ffffffff8104edd8: mov $0xc,%ecx
    - ffffffff8104eddd: mov %r13,%rdi
    - ffffffff8104ede0: mov $0x30,%eax
    - ffffffff8104ede5: mov %rdx,%rsi
    - ffffffff8104ede8: rep movsl %ds:(%rsi),%es:(%rdi)
    - ffffffff8104edea: test $0x2,%al
    - ffffffff8104edec: je ffffffff8104edf0 <__dequeue_signal+0xd0>
    - ffffffff8104edee: movsw %ds:(%rsi),%es:(%rdi)
    - ffffffff8104edf0: test $0x1,%al
    - ffffffff8104edf2: je ffffffff8104edf5 <__dequeue_signal+0xd5>
    - ffffffff8104edf4: movsb %ds:(%rsi),%es:(%rdi)
    - ffffffff8104edf5: mov %r8,%rdi
    - ffffffff8104edf8: callq ffffffff8104de60 <__sigqueue_free>
    -
    -As expected, it's the "``rep movsl``" instruction from the ``memcpy()``
    -that causes the warning. We know about ``REP MOVSL`` that it uses the register
    -``RCX`` to count the number of remaining iterations. By taking a look at the
    -register dump again (from the kmemcheck report), we can figure out how many
    -bytes were left to copy::
    -
    - RAX: 0000000000000030 RBX: ffff88003d4ea968 RCX: 0000000000000009
    -
    -By looking at the disassembly, we also see that ``%ecx`` is being loaded
    -with the value ``$0xc`` just before (ffffffff8104edd8), so we are very
    -lucky. Keep in mind that this is the number of iterations, not bytes. And
    -since this is a "long" operation, we need to multiply by 4 to get the
    -number of bytes. So this means that the uninitialized value was encountered
    -at 4 * (0xc - 0x9) = 12 bytes from the start of the object.
    -
    -We can now try to figure out which field of the "``struct siginfo``" that
    -was not initialized. This is the beginning of the struct::
    -
    - 40 typedef struct siginfo {
    - 41 int si_signo;
    - 42 int si_errno;
    - 43 int si_code;
    - 44
    - 45 union {
    - ..
    - 92 } _sifields;
    - 93 } siginfo_t;
    -
    -On 64-bit, the int is 4 bytes long, so it must the union member that has
    -not been initialized. We can verify this using gdb::
    -
    - $ gdb vmlinux
    - ...
    - (gdb) p &((struct siginfo *) 0)->_sifields
    - $1 = (union {...} *) 0x10
    -
    -Actually, it seems that the union member is located at offset 0x10 -- which
    -means that gcc has inserted 4 bytes of padding between the members ``si_code``
    -and ``_sifields``. We can now get a fuller picture of the memory dump::
    -
    - _----------------------------=> si_code
    - / _--------------------=> (padding)
    - | / _------------=> _sifields(._kill._pid)
    - | | / _----=> _sifields(._kill._uid)
    - | | | /
    - -------|-------|-------|-------|
    - 80000000000000000000000000000000000000000088ffff0000000000000000
    - i i i i u u u u i i i i i i i i u u u u u u u u u u u u u u u u
    -
    -This allows us to realize another important fact: ``si_code`` contains the
    -value 0x80. Remember that x86 is little endian, so the first 4 bytes
    -"80000000" are really the number 0x00000080. With a bit of research, we
    -find that this is actually the constant ``SI_KERNEL`` defined in
    -``include/asm-generic/siginfo.h``::
    -
    - 144 #define SI_KERNEL 0x80 /* sent by the kernel from somewhere */
    -
    -This macro is used in exactly one place in the x86 kernel: In ``send_signal()``
    -in ``kernel/signal.c``::
    -
    - 816 static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
    - 817 int group)
    - 818 {
    - ...
    - 828 pending = group ? &t->signal->shared_pending : &t->pending;
    - ...
    - 851 q = __sigqueue_alloc(t, GFP_ATOMIC, (sig < SIGRTMIN &&
    - 852 (is_si_special(info) ||
    - 853 info->si_code >= 0)));
    - 854 if (q) {
    - 855 list_add_tail(&q->list, &pending->list);
    - 856 switch ((unsigned long) info) {
    - ...
    - 865 case (unsigned long) SEND_SIG_PRIV:
    - 866 q->info.si_signo = sig;
    - 867 q->info.si_errno = 0;
    - 868 q->info.si_code = SI_KERNEL;
    - 869 q->info.si_pid = 0;
    - 870 q->info.si_uid = 0;
    - 871 break;
    - ...
    - 890 }
    -
    -Not only does this match with the ``.si_code`` member, it also matches the place
    -we found earlier when looking for where siginfo_t objects are enqueued on the
    -``shared_pending`` list.
    -
    -So to sum up: It seems that it is the padding introduced by the compiler
    -between two struct fields that is uninitialized, and this gets reported when
    -we do a ``memcpy()`` on the struct. This means that we have identified a false
    -positive warning.
    -
    -Normally, kmemcheck will not report uninitialized accesses in ``memcpy()`` calls
    -when both the source and destination addresses are tracked. (Instead, we copy
    -the shadow bytemap as well). In this case, the destination address clearly
    -was not tracked. We can dig a little deeper into the stack trace from above::
    -
    - arch/x86/kernel/signal.c:805
    - arch/x86/kernel/signal.c:871
    - arch/x86/kernel/entry_64.S:694
    -
    -And we clearly see that the destination siginfo object is located on the
    -stack::
    -
    - 782 static void do_signal(struct pt_regs *regs)
    - 783 {
    - 784 struct k_sigaction ka;
    - 785 siginfo_t info;
    - ...
    - 804 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
    - ...
    - 854 }
    -
    -And this ``&info`` is what eventually gets passed to ``copy_siginfo()`` as the
    -destination argument.
    -
    -Now, even though we didn't find an actual error here, the example is still a
    -good one, because it shows how one would go about to find out what the report
    -was all about.
    -
    -
    -Annotating false positives
    -~~~~~~~~~~~~~~~~~~~~~~~~~~
    -
    -There are a few different ways to make annotations in the source code that
    -will keep kmemcheck from checking and reporting certain allocations. Here
    -they are:
    -
    -- ``__GFP_NOTRACK_FALSE_POSITIVE``
    - This flag can be passed to ``kmalloc()`` or ``kmem_cache_alloc()``
    - (therefore also to other functions that end up calling one of
    - these) to indicate that the allocation should not be tracked
    - because it would lead to a false positive report. This is a "big
    - hammer" way of silencing kmemcheck; after all, even if the false
    - positive pertains to particular field in a struct, for example, we
    - will now lose the ability to find (real) errors in other parts of
    - the same struct.
    -
    - Example::
    -
    - /* No warnings will ever trigger on accessing any part of x */
    - x = kmalloc(sizeof *x, GFP_KERNEL | __GFP_NOTRACK_FALSE_POSITIVE);
    -
    -- ``kmemcheck_bitfield_begin(name)``/``kmemcheck_bitfield_end(name)`` and
    - ``kmemcheck_annotate_bitfield(ptr, name)``
    - The first two of these three macros can be used inside struct
    - definitions to signal, respectively, the beginning and end of a
    - bitfield. Additionally, this will assign the bitfield a name, which
    - is given as an argument to the macros.
    -
    - Having used these markers, one can later use
    - kmemcheck_annotate_bitfield() at the point of allocation, to indicate
    - which parts of the allocation is part of a bitfield.
    -
    - Example::
    -
    - struct foo {
    - int x;
    -
    - kmemcheck_bitfield_begin(flags);
    - int flag_a:1;
    - int flag_b:1;
    - kmemcheck_bitfield_end(flags);
    -
    - int y;
    - };
    -
    - struct foo *x = kmalloc(sizeof *x);
    -
    - /* No warnings will trigger on accessing the bitfield of x */
    - kmemcheck_annotate_bitfield(x, flags);
    -
    - Note that ``kmemcheck_annotate_bitfield()`` can be used even before the
    - return value of ``kmalloc()`` is checked -- in other words, passing NULL
    - as the first argument is legal (and will do nothing).
    -
    -
    -Reporting errors
    -----------------
    -
    -As we have seen, kmemcheck will produce false positive reports. Therefore, it
    -is not very wise to blindly post kmemcheck warnings to mailing lists and
    -maintainers. Instead, I encourage maintainers and developers to find errors
    -in their own code. If you get a warning, you can try to work around it, try
    -to figure out if it's a real error or not, or simply ignore it. Most
    -developers know their own code and will quickly and efficiently determine the
    -root cause of a kmemcheck report. This is therefore also the most efficient
    -way to work with kmemcheck.
    -
    -That said, we (the kmemcheck maintainers) will always be on the lookout for
    -false positives that we can annotate and silence. So whatever you find,
    -please drop us a note privately! Kernel configs and steps to reproduce (if
    -available) are of course a great help too.
    -
    -Happy hacking!
    -
    -
    -Technical description
    ----------------------
    -
    -kmemcheck works by marking memory pages non-present. This means that whenever
    -somebody attempts to access the page, a page fault is generated. The page
    -fault handler notices that the page was in fact only hidden, and so it calls
    -on the kmemcheck code to make further investigations.
    -
    -When the investigations are completed, kmemcheck "shows" the page by marking
    -it present (as it would be under normal circumstances). This way, the
    -interrupted code can continue as usual.
    -
    -But after the instruction has been executed, we should hide the page again, so
    -that we can catch the next access too! Now kmemcheck makes use of a debugging
    -feature of the processor, namely single-stepping. When the processor has
    -finished the one instruction that generated the memory access, a debug
    -exception is raised. From here, we simply hide the page again and continue
    -execution, this time with the single-stepping feature turned off.
    -
    -kmemcheck requires some assistance from the memory allocator in order to work.
    -The memory allocator needs to
    -
    - 1. Tell kmemcheck about newly allocated pages and pages that are about to
    - be freed. This allows kmemcheck to set up and tear down the shadow memory
    - for the pages in question. The shadow memory stores the status of each
    - byte in the allocation proper, e.g. whether it is initialized or
    - uninitialized.
    -
    - 2. Tell kmemcheck which parts of memory should be marked uninitialized.
    - There are actually a few more states, such as "not yet allocated" and
    - "recently freed".
    -
    -If a slab cache is set up using the SLAB_NOTRACK flag, it will never return
    -memory that can take page faults because of kmemcheck.
    -
    -If a slab cache is NOT set up using the SLAB_NOTRACK flag, callers can still
    -request memory with the __GFP_NOTRACK or __GFP_NOTRACK_FALSE_POSITIVE flags.
    -This does not prevent the page faults from occurring, however, but marks the
    -object in question as being initialized so that no warnings will ever be
    -produced for this object.
    -
    -Currently, the SLAB and SLUB allocators are supported by kmemcheck.
    diff --git a/MAINTAINERS b/MAINTAINERS
    index 38d3e4ed7208..b3b7a8c99567 100644
    --- a/MAINTAINERS
    +++ b/MAINTAINERS
    @@ -7285,16 +7285,6 @@ F: include/linux/kdb.h
    F: include/linux/kgdb.h
    F: kernel/debug/

    -KMEMCHECK
    -M: Vegard Nossum <vegardno@ifi.uio.no>
    -M: Pekka Enberg <penberg@kernel.org>
    -S: Maintained
    -F: Documentation/dev-tools/kmemcheck.rst
    -F: arch/x86/include/asm/kmemcheck.h
    -F: arch/x86/mm/kmemcheck/
    -F: include/linux/kmemcheck.h
    -F: mm/kmemcheck.c
    -
    KMEMLEAK
    M: Catalin Marinas <catalin.marinas@arm.com>
    S: Maintained
    diff --git a/arch/arm/include/asm/dma-iommu.h b/arch/arm/include/asm/dma-iommu.h
    index 2ef282f96651..1a6a870b8fd6 100644
    --- a/arch/arm/include/asm/dma-iommu.h
    +++ b/arch/arm/include/asm/dma-iommu.h
    @@ -6,7 +6,6 @@
    #include <linux/mm_types.h>
    #include <linux/scatterlist.h>
    #include <linux/dma-debug.h>
    -#include <linux/kmemcheck.h>
    #include <linux/kref.h>

    struct dma_iommu_mapping {
    diff --git a/arch/openrisc/include/asm/dma-mapping.h b/arch/openrisc/include/asm/dma-mapping.h
    index 0c0075f17145..f18899b9993d 100644
    --- a/arch/openrisc/include/asm/dma-mapping.h
    +++ b/arch/openrisc/include/asm/dma-mapping.h
    @@ -23,7 +23,6 @@
    */

    #include <linux/dma-debug.h>
    -#include <linux/kmemcheck.h>
    #include <linux/dma-mapping.h>

    #define DMA_ERROR_CODE (~(dma_addr_t)0x0)
    diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
    index cc98d5a294ee..cc155b9175bc 100644
    --- a/arch/x86/Kconfig
    +++ b/arch/x86/Kconfig
    @@ -103,7 +103,6 @@ config X86
    select HAVE_ARCH_JUMP_LABEL
    select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
    select HAVE_ARCH_KGDB
    - select HAVE_ARCH_KMEMCHECK
    select HAVE_ARCH_MMAP_RND_BITS if MMU
    select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
    select HAVE_ARCH_SECCOMP_FILTER
    @@ -1390,7 +1389,7 @@ config ARCH_DMA_ADDR_T_64BIT

    config X86_DIRECT_GBPAGES
    def_bool y
    - depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
    + depends on X86_64 && !DEBUG_PAGEALLOC
    ---help---
    Certain kernel features effectively disable kernel
    linear 1 GB mappings (even if the CPU otherwise
    diff --git a/arch/x86/Makefile b/arch/x86/Makefile
    index 49d160b781f0..d7926124378d 100644
    --- a/arch/x86/Makefile
    +++ b/arch/x86/Makefile
    @@ -138,11 +138,6 @@ ifdef CONFIG_X86_X32
    endif
    export CONFIG_X86_X32_ABI

    -# Don't unroll struct assignments with kmemcheck enabled
    -ifeq ($(CONFIG_KMEMCHECK),y)
    - KBUILD_CFLAGS += $(call cc-option,-fno-builtin-memcpy)
    -endif
    -
    #
    # If the function graph tracer is used with mcount instead of fentry,
    # '-maccumulate-outgoing-args' is needed to prevent a GCC bug
    diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
    index 08a0838b83fb..c6558462953a 100644
    --- a/arch/x86/include/asm/dma-mapping.h
    +++ b/arch/x86/include/asm/dma-mapping.h
    @@ -6,7 +6,6 @@
    * Documentation/DMA-API.txt for documentation.
    */

    -#include <linux/kmemcheck.h>
    #include <linux/scatterlist.h>
    #include <linux/dma-debug.h>
    #include <asm/io.h>
    diff --git a/arch/x86/include/asm/kmemcheck.h b/arch/x86/include/asm/kmemcheck.h
    deleted file mode 100644
    index ed01518f297e..000000000000
    --- a/arch/x86/include/asm/kmemcheck.h
    +++ /dev/null
    @@ -1,42 +0,0 @@
    -#ifndef ASM_X86_KMEMCHECK_H
    -#define ASM_X86_KMEMCHECK_H
    -
    -#include <linux/types.h>
    -#include <asm/ptrace.h>
    -
    -#ifdef CONFIG_KMEMCHECK
    -bool kmemcheck_active(struct pt_regs *regs);
    -
    -void kmemcheck_show(struct pt_regs *regs);
    -void kmemcheck_hide(struct pt_regs *regs);
    -
    -bool kmemcheck_fault(struct pt_regs *regs,
    - unsigned long address, unsigned long error_code);
    -bool kmemcheck_trap(struct pt_regs *regs);
    -#else
    -static inline bool kmemcheck_active(struct pt_regs *regs)
    -{
    - return false;
    -}
    -
    -static inline void kmemcheck_show(struct pt_regs *regs)
    -{
    -}
    -
    -static inline void kmemcheck_hide(struct pt_regs *regs)
    -{
    -}
    -
    -static inline bool kmemcheck_fault(struct pt_regs *regs,
    - unsigned long address, unsigned long error_code)
    -{
    - return false;
    -}
    -
    -static inline bool kmemcheck_trap(struct pt_regs *regs)
    -{
    - return false;
    -}
    -#endif /* CONFIG_KMEMCHECK */
    -
    -#endif
    diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
    index 62484333673d..baf03bc24c4e 100644
    --- a/arch/x86/include/asm/pgtable_types.h
    +++ b/arch/x86/include/asm/pgtable_types.h
    @@ -76,11 +76,11 @@
    #define _PAGE_KNL_ERRATUM_MASK 0
    #endif

    -#ifdef CONFIG_KMEMCHECK
    -#define _PAGE_HIDDEN (_AT(pteval_t, 1) << _PAGE_BIT_HIDDEN)
    -#else
    +/*
    + * Used by kmemcheck in the past; obsolete, but kept for the sake of
    + * out-of-tree module source backwards compatibility.
    + */
    #define _PAGE_HIDDEN (_AT(pteval_t, 0))
    -#endif

    /*
    * The same hidden bit is used by kmemcheck, but since kmemcheck
    diff --git a/arch/x86/include/asm/string_32.h b/arch/x86/include/asm/string_32.h
    index 3d3e8353ee5c..8a4f6fa41d07 100644
    --- a/arch/x86/include/asm/string_32.h
    +++ b/arch/x86/include/asm/string_32.h
    @@ -176,8 +176,6 @@ static inline void *__memcpy3d(void *to, const void *from, size_t len)
    * No 3D Now!
    */

    -#ifndef CONFIG_KMEMCHECK
    -
    #if (__GNUC__ >= 4)
    #define memcpy(t, f, n) __builtin_memcpy(t, f, n)
    #else
    @@ -186,13 +184,6 @@ static inline void *__memcpy3d(void *to, const void *from, size_t len)
    ? __constant_memcpy((t), (f), (n)) \
    : __memcpy((t), (f), (n)))
    #endif
    -#else
    -/*
    - * kmemcheck becomes very happy if we use the REP instructions unconditionally,
    - * because it means that we know both memory operands in advance.
    - */
    -#define memcpy(t, f, n) __memcpy((t), (f), (n))
    -#endif

    #endif

    diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
    index a164862d77e3..709f41c0a461 100644
    --- a/arch/x86/include/asm/string_64.h
    +++ b/arch/x86/include/asm/string_64.h
    @@ -31,7 +31,6 @@ static __always_inline void *__inline_memcpy(void *to, const void *from, size_t
    extern void *memcpy(void *to, const void *from, size_t len);
    extern void *__memcpy(void *to, const void *from, size_t len);

    -#ifndef CONFIG_KMEMCHECK
    #if (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || __GNUC__ < 4
    #define memcpy(dst, src, len) \
    ({ \
    @@ -44,13 +43,6 @@ extern void *__memcpy(void *to, const void *from, size_t len);
    __ret; \
    })
    #endif
    -#else
    -/*
    - * kmemcheck becomes very happy if we use the REP instructions unconditionally,
    - * because it means that we know both memory operands in advance.
    - */
    -#define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
    -#endif

    #define __HAVE_ARCH_MEMSET
    void *memset(void *s, int c, size_t n);
    diff --git a/arch/x86/include/asm/xor.h b/arch/x86/include/asm/xor.h
    index 1f5c5161ead6..45c8605467f1 100644
    --- a/arch/x86/include/asm/xor.h
    +++ b/arch/x86/include/asm/xor.h
    @@ -1,7 +1,4 @@
    -#ifdef CONFIG_KMEMCHECK
    -/* kmemcheck doesn't handle MMX/SSE/SSE2 instructions */
    -# include <asm-generic/xor.h>
    -#elif !defined(_ASM_X86_XOR_H)
    +#ifndef _ASM_X86_XOR_H
    #define _ASM_X86_XOR_H

    /*
    diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
    index 063197771b8d..4ab65638170f 100644
    --- a/arch/x86/kernel/cpu/intel.c
    +++ b/arch/x86/kernel/cpu/intel.c
    @@ -190,21 +190,6 @@ static void early_init_intel(struct cpuinfo_x86 *c)
    if (c->x86 == 6 && c->x86_model < 15)
    clear_cpu_cap(c, X86_FEATURE_PAT);

    -#ifdef CONFIG_KMEMCHECK
    - /*
    - * P4s have a "fast strings" feature which causes single-
    - * stepping REP instructions to only generate a #DB on
    - * cache-line boundaries.
    - *
    - * Ingo Molnar reported a Pentium D (model 6) and a Xeon
    - * (model 2) with the same problem.
    - */
    - if (c->x86 == 15)
    - if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
    - MSR_IA32_MISC_ENABLE_FAST_STRING_BIT) > 0)
    - pr_info("kmemcheck: Disabling fast string operations\n");
    -#endif
    -
    /*
    * If fast string is not enabled in IA32_MISC_ENABLE for any reason,
    * clear the fast string and enhanced fast string CPU capabilities.
    diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
    index 4e496379a871..d7007257ae72 100644
    --- a/arch/x86/kernel/traps.c
    +++ b/arch/x86/kernel/traps.c
    @@ -47,7 +47,6 @@
    #include <linux/edac.h>
    #endif

    -#include <asm/kmemcheck.h>
    #include <asm/stacktrace.h>
    #include <asm/processor.h>
    #include <asm/debugreg.h>
    @@ -718,10 +717,6 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
    if (!dr6 && user_mode(regs))
    user_icebp = 1;

    - /* Catch kmemcheck conditions! */
    - if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
    - goto exit;
    -
    /* Store the virtualized DR6 value */
    tsk->thread.debugreg6 = dr6;

    diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
    index 96d2b847e09e..b90fdfb79201 100644
    --- a/arch/x86/mm/Makefile
    +++ b/arch/x86/mm/Makefile
    @@ -21,8 +21,6 @@ obj-$(CONFIG_X86_PTDUMP) += debug_pagetables.o

    obj-$(CONFIG_HIGHMEM) += highmem_32.o

    -obj-$(CONFIG_KMEMCHECK) += kmemcheck/
    -
    KASAN_SANITIZE_kasan_init_$(BITS).o := n
    obj-$(CONFIG_KASAN) += kasan_init_$(BITS).o

    diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
    index 428e31763cb9..099c256c37a1 100644
    --- a/arch/x86/mm/fault.c
    +++ b/arch/x86/mm/fault.c
    @@ -19,7 +19,6 @@
    #include <asm/cpufeature.h> /* boot_cpu_has, ... */
    #include <asm/traps.h> /* dotraplinkage, ... */
    #include <asm/pgalloc.h> /* pgd_*(), ... */
    -#include <asm/kmemcheck.h> /* kmemcheck_*(), ... */
    #include <asm/fixmap.h> /* VSYSCALL_ADDR */
    #include <asm/vsyscall.h> /* emulate_vsyscall */
    #include <asm/vm86.h> /* struct vm86 */
    @@ -1228,8 +1227,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
    * Detect and handle instructions that would cause a page fault for
    * both a tracked kernel page and a userspace page.
    */
    - if (kmemcheck_active(regs))
    - kmemcheck_hide(regs);
    prefetchw(&mm->mmap_sem);

    if (unlikely(kmmio_fault(regs, address)))
    @@ -1252,9 +1249,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
    if (!(error_code & (PF_RSVD | PF_USER | PF_PROT))) {
    if (vmalloc_fault(address) >= 0)
    return;
    -
    - if (kmemcheck_fault(regs, address, error_code))
    - return;
    }

    /* Can handle a stale RO->RW TLB: */
    diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
    index 889e7619a091..9cfa27385c29 100644
    --- a/arch/x86/mm/init.c
    +++ b/arch/x86/mm/init.c
    @@ -161,16 +161,13 @@ static int page_size_mask;

    static void __init probe_page_size_mask(void)
    {
    -#if !defined(CONFIG_KMEMCHECK)
    /*
    - * For CONFIG_KMEMCHECK or pagealloc debugging, identity mapping will
    - * use small pages.
    + * For pagealloc debugging, identity mapping will use small pages.
    * This will simplify cpa(), which otherwise needs to support splitting
    * large pages into small in interrupt context, etc.
    */
    if (boot_cpu_has(X86_FEATURE_PSE) && !debug_pagealloc_enabled())
    page_size_mask |= 1 << PG_LEVEL_2M;
    -#endif

    /* Enable PSE if available */
    if (boot_cpu_has(X86_FEATURE_PSE))
    diff --git a/arch/x86/mm/kmemcheck/Makefile b/arch/x86/mm/kmemcheck/Makefile
    deleted file mode 100644
    index 520b3bce4095..000000000000
    --- a/arch/x86/mm/kmemcheck/Makefile
    +++ /dev/null
    @@ -1 +0,0 @@
    -obj-y := error.o kmemcheck.o opcode.o pte.o selftest.o shadow.o
    diff --git a/arch/x86/mm/kmemcheck/error.c b/arch/x86/mm/kmemcheck/error.c
    deleted file mode 100644
    index dab41876cdd5..000000000000
    --- a/arch/x86/mm/kmemcheck/error.c
    +++ /dev/null
    @@ -1,227 +0,0 @@
    -#include <linux/interrupt.h>
    -#include <linux/kdebug.h>
    -#include <linux/kmemcheck.h>
    -#include <linux/kernel.h>
    -#include <linux/types.h>
    -#include <linux/ptrace.h>
    -#include <linux/stacktrace.h>
    -#include <linux/string.h>
    -
    -#include "error.h"
    -#include "shadow.h"
    -
    -enum kmemcheck_error_type {
    - KMEMCHECK_ERROR_INVALID_ACCESS,
    - KMEMCHECK_ERROR_BUG,
    -};
    -
    -#define SHADOW_COPY_SIZE (1 << CONFIG_KMEMCHECK_SHADOW_COPY_SHIFT)
    -
    -struct kmemcheck_error {
    - enum kmemcheck_error_type type;
    -
    - union {
    - /* KMEMCHECK_ERROR_INVALID_ACCESS */
    - struct {
    - /* Kind of access that caused the error */
    - enum kmemcheck_shadow state;
    - /* Address and size of the erroneous read */
    - unsigned long address;
    - unsigned int size;
    - };
    - };
    -
    - struct pt_regs regs;
    - struct stack_trace trace;
    - unsigned long trace_entries[32];
    -
    - /* We compress it to a char. */
    - unsigned char shadow_copy[SHADOW_COPY_SIZE];
    - unsigned char memory_copy[SHADOW_COPY_SIZE];
    -};
    -
    -/*
    - * Create a ring queue of errors to output. We can't call printk() directly
    - * from the kmemcheck traps, since this may call the console drivers and
    - * result in a recursive fault.
    - */
    -static struct kmemcheck_error error_fifo[CONFIG_KMEMCHECK_QUEUE_SIZE];
    -static unsigned int error_count;
    -static unsigned int error_rd;
    -static unsigned int error_wr;
    -static unsigned int error_missed_count;
    -
    -static struct kmemcheck_error *error_next_wr(void)
    -{
    - struct kmemcheck_error *e;
    -
    - if (error_count == ARRAY_SIZE(error_fifo)) {
    - ++error_missed_count;
    - return NULL;
    - }
    -
    - e = &error_fifo[error_wr];
    - if (++error_wr == ARRAY_SIZE(error_fifo))
    - error_wr = 0;
    - ++error_count;
    - return e;
    -}
    -
    -static struct kmemcheck_error *error_next_rd(void)
    -{
    - struct kmemcheck_error *e;
    -
    - if (error_count == 0)
    - return NULL;
    -
    - e = &error_fifo[error_rd];
    - if (++error_rd == ARRAY_SIZE(error_fifo))
    - error_rd = 0;
    - --error_count;
    - return e;
    -}
    -
    -void kmemcheck_error_recall(void)
    -{
    - static const char *desc[] = {
    - [KMEMCHECK_SHADOW_UNALLOCATED] = "unallocated",
    - [KMEMCHECK_SHADOW_UNINITIALIZED] = "uninitialized",
    - [KMEMCHECK_SHADOW_INITIALIZED] = "initialized",
    - [KMEMCHECK_SHADOW_FREED] = "freed",
    - };
    -
    - static const char short_desc[] = {
    - [KMEMCHECK_SHADOW_UNALLOCATED] = 'a',
    - [KMEMCHECK_SHADOW_UNINITIALIZED] = 'u',
    - [KMEMCHECK_SHADOW_INITIALIZED] = 'i',
    - [KMEMCHECK_SHADOW_FREED] = 'f',
    - };
    -
    - struct kmemcheck_error *e;
    - unsigned int i;
    -
    - e = error_next_rd();
    - if (!e)
    - return;
    -
    - switch (e->type) {
    - case KMEMCHECK_ERROR_INVALID_ACCESS:
    - printk(KERN_WARNING "WARNING: kmemcheck: Caught %d-bit read from %s memory (%p)\n",
    - 8 * e->size, e->state < ARRAY_SIZE(desc) ?
    - desc[e->state] : "(invalid shadow state)",
    - (void *) e->address);
    -
    - printk(KERN_WARNING);
    - for (i = 0; i < SHADOW_COPY_SIZE; ++i)
    - printk(KERN_CONT "%02x", e->memory_copy[i]);
    - printk(KERN_CONT "\n");
    -
    - printk(KERN_WARNING);
    - for (i = 0; i < SHADOW_COPY_SIZE; ++i) {
    - if (e->shadow_copy[i] < ARRAY_SIZE(short_desc))
    - printk(KERN_CONT " %c", short_desc[e->shadow_copy[i]]);
    - else
    - printk(KERN_CONT " ?");
    - }
    - printk(KERN_CONT "\n");
    - printk(KERN_WARNING "%*c\n", 2 + 2
    - * (int) (e->address & (SHADOW_COPY_SIZE - 1)), '^');
    - break;
    - case KMEMCHECK_ERROR_BUG:
    - printk(KERN_EMERG "ERROR: kmemcheck: Fatal error\n");
    - break;
    - }
    -
    - __show_regs(&e->regs, 1);
    - print_stack_trace(&e->trace, 0);
    -}
    -
    -static void do_wakeup(unsigned long data)
    -{
    - while (error_count > 0)
    - kmemcheck_error_recall();
    -
    - if (error_missed_count > 0) {
    - printk(KERN_WARNING "kmemcheck: Lost %d error reports because "
    - "the queue was too small\n", error_missed_count);
    - error_missed_count = 0;
    - }
    -}
    -
    -static DECLARE_TASKLET(kmemcheck_tasklet, &do_wakeup, 0);
    -
    -/*
    - * Save the context of an error report.
    - */
    -void kmemcheck_error_save(enum kmemcheck_shadow state,
    - unsigned long address, unsigned int size, struct pt_regs *regs)
    -{
    - static unsigned long prev_ip;
    -
    - struct kmemcheck_error *e;
    - void *shadow_copy;
    - void *memory_copy;
    -
    - /* Don't report several adjacent errors from the same EIP. */
    - if (regs->ip == prev_ip)
    - return;
    - prev_ip = regs->ip;
    -
    - e = error_next_wr();
    - if (!e)
    - return;
    -
    - e->type = KMEMCHECK_ERROR_INVALID_ACCESS;
    -
    - e->state = state;
    - e->address = address;
    - e->size = size;
    -
    - /* Save regs */
    - memcpy(&e->regs, regs, sizeof(*regs));
    -
    - /* Save stack trace */
    - e->trace.nr_entries = 0;
    - e->trace.entries = e->trace_entries;
    - e->trace.max_entries = ARRAY_SIZE(e->trace_entries);
    - e->trace.skip = 0;
    - save_stack_trace_regs(regs, &e->trace);
    -
    - /* Round address down to nearest 16 bytes */
    - shadow_copy = kmemcheck_shadow_lookup(address
    - & ~(SHADOW_COPY_SIZE - 1));
    - BUG_ON(!shadow_copy);
    -
    - memcpy(e->shadow_copy, shadow_copy, SHADOW_COPY_SIZE);
    -
    - kmemcheck_show_addr(address);
    - memory_copy = (void *) (address & ~(SHADOW_COPY_SIZE - 1));
    - memcpy(e->memory_copy, memory_copy, SHADOW_COPY_SIZE);
    - kmemcheck_hide_addr(address);
    -
    - tasklet_hi_schedule_first(&kmemcheck_tasklet);
    -}
    -
    -/*
    - * Save the context of a kmemcheck bug.
    - */
    -void kmemcheck_error_save_bug(struct pt_regs *regs)
    -{
    - struct kmemcheck_error *e;
    -
    - e = error_next_wr();
    - if (!e)
    - return;
    -
    - e->type = KMEMCHECK_ERROR_BUG;
    -
    - memcpy(&e->regs, regs, sizeof(*regs));
    -
    - e->trace.nr_entries = 0;
    - e->trace.entries = e->trace_entries;
    - e->trace.max_entries = ARRAY_SIZE(e->trace_entries);
    - e->trace.skip = 1;
    - save_stack_trace(&e->trace);
    -
    - tasklet_hi_schedule_first(&kmemcheck_tasklet);
    -}
    diff --git a/arch/x86/mm/kmemcheck/error.h b/arch/x86/mm/kmemcheck/error.h
    deleted file mode 100644
    index 0efc2e8d0a20..000000000000
    --- a/arch/x86/mm/kmemcheck/error.h
    +++ /dev/null
    @@ -1,15 +0,0 @@
    -#ifndef ARCH__X86__MM__KMEMCHECK__ERROR_H
    -#define ARCH__X86__MM__KMEMCHECK__ERROR_H
    -
    -#include <linux/ptrace.h>
    -
    -#include "shadow.h"
    -
    -void kmemcheck_error_save(enum kmemcheck_shadow state,
    - unsigned long address, unsigned int size, struct pt_regs *regs);
    -
    -void kmemcheck_error_save_bug(struct pt_regs *regs);
    -
    -void kmemcheck_error_recall(void);
    -
    -#endif
    diff --git a/arch/x86/mm/kmemcheck/kmemcheck.c b/arch/x86/mm/kmemcheck/kmemcheck.c
    deleted file mode 100644
    index 4515bae36bbe..000000000000
    --- a/arch/x86/mm/kmemcheck/kmemcheck.c
    +++ /dev/null
    @@ -1,658 +0,0 @@
    -/**
    - * kmemcheck - a heavyweight memory checker for the linux kernel
    - * Copyright (C) 2007, 2008 Vegard Nossum <vegardno@ifi.uio.no>
    - * (With a lot of help from Ingo Molnar and Pekka Enberg.)
    - *
    - * This program is free software; you can redistribute it and/or modify
    - * it under the terms of the GNU General Public License (version 2) as
    - * published by the Free Software Foundation.
    - */
    -
    -#include <linux/init.h>
    -#include <linux/interrupt.h>
    -#include <linux/kallsyms.h>
    -#include <linux/kernel.h>
    -#include <linux/kmemcheck.h>
    -#include <linux/mm.h>
    -#include <linux/page-flags.h>
    -#include <linux/percpu.h>
    -#include <linux/ptrace.h>
    -#include <linux/string.h>
    -#include <linux/types.h>
    -
    -#include <asm/cacheflush.h>
    -#include <asm/kmemcheck.h>
    -#include <asm/pgtable.h>
    -#include <asm/tlbflush.h>
    -
    -#include "error.h"
    -#include "opcode.h"
    -#include "pte.h"
    -#include "selftest.h"
    -#include "shadow.h"
    -
    -
    -#ifdef CONFIG_KMEMCHECK_DISABLED_BY_DEFAULT
    -# define KMEMCHECK_ENABLED 0
    -#endif
    -
    -#ifdef CONFIG_KMEMCHECK_ENABLED_BY_DEFAULT
    -# define KMEMCHECK_ENABLED 1
    -#endif
    -
    -#ifdef CONFIG_KMEMCHECK_ONESHOT_BY_DEFAULT
    -# define KMEMCHECK_ENABLED 2
    -#endif
    -
    -int kmemcheck_enabled = KMEMCHECK_ENABLED;
    -
    -int __init kmemcheck_init(void)
    -{
    -#ifdef CONFIG_SMP
    - /*
    - * Limit SMP to use a single CPU. We rely on the fact that this code
    - * runs before SMP is set up.
    - */
    - if (setup_max_cpus > 1) {
    - printk(KERN_INFO
    - "kmemcheck: Limiting number of CPUs to 1.\n");
    - setup_max_cpus = 1;
    - }
    -#endif
    -
    - if (!kmemcheck_selftest()) {
    - printk(KERN_INFO "kmemcheck: self-tests failed; disabling\n");
    - kmemcheck_enabled = 0;
    - return -EINVAL;
    - }
    -
    - printk(KERN_INFO "kmemcheck: Initialized\n");
    - return 0;
    -}
    -
    -early_initcall(kmemcheck_init);
    -
    -/*
    - * We need to parse the kmemcheck= option before any memory is allocated.
    - */
    -static int __init param_kmemcheck(char *str)
    -{
    - int val;
    - int ret;
    -
    - if (!str)
    - return -EINVAL;
    -
    - ret = kstrtoint(str, 0, &val);
    - if (ret)
    - return ret;
    - kmemcheck_enabled = val;
    - return 0;
    -}
    -
    -early_param("kmemcheck", param_kmemcheck);
    -
    -int kmemcheck_show_addr(unsigned long address)
    -{
    - pte_t *pte;
    -
    - pte = kmemcheck_pte_lookup(address);
    - if (!pte)
    - return 0;
    -
    - set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
    - __flush_tlb_one(address);
    - return 1;
    -}
    -
    -int kmemcheck_hide_addr(unsigned long address)
    -{
    - pte_t *pte;
    -
    - pte = kmemcheck_pte_lookup(address);
    - if (!pte)
    - return 0;
    -
    - set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
    - __flush_tlb_one(address);
    - return 1;
    -}
    -
    -struct kmemcheck_context {
    - bool busy;
    - int balance;
    -
    - /*
    - * There can be at most two memory operands to an instruction, but
    - * each address can cross a page boundary -- so we may need up to
    - * four addresses that must be hidden/revealed for each fault.
    - */
    - unsigned long addr[4];
    - unsigned long n_addrs;
    - unsigned long flags;
    -
    - /* Data size of the instruction that caused a fault. */
    - unsigned int size;
    -};
    -
    -static DEFINE_PER_CPU(struct kmemcheck_context, kmemcheck_context);
    -
    -bool kmemcheck_active(struct pt_regs *regs)
    -{
    - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
    -
    - return data->balance > 0;
    -}
    -
    -/* Save an address that needs to be shown/hidden */
    -static void kmemcheck_save_addr(unsigned long addr)
    -{
    - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
    -
    - BUG_ON(data->n_addrs >= ARRAY_SIZE(data->addr));
    - data->addr[data->n_addrs++] = addr;
    -}
    -
    -static unsigned int kmemcheck_show_all(void)
    -{
    - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
    - unsigned int i;
    - unsigned int n;
    -
    - n = 0;
    - for (i = 0; i < data->n_addrs; ++i)
    - n += kmemcheck_show_addr(data->addr[i]);
    -
    - return n;
    -}
    -
    -static unsigned int kmemcheck_hide_all(void)
    -{
    - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
    - unsigned int i;
    - unsigned int n;
    -
    - n = 0;
    - for (i = 0; i < data->n_addrs; ++i)
    - n += kmemcheck_hide_addr(data->addr[i]);
    -
    - return n;
    -}
    -
    -/*
    - * Called from the #PF handler.
    - */
    -void kmemcheck_show(struct pt_regs *regs)
    -{
    - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
    -
    - BUG_ON(!irqs_disabled());
    -
    - if (unlikely(data->balance != 0)) {
    - kmemcheck_show_all();
    - kmemcheck_error_save_bug(regs);
    - data->balance = 0;
    - return;
    - }
    -
    - /*
    - * None of the addresses actually belonged to kmemcheck. Note that
    - * this is not an error.
    - */
    - if (kmemcheck_show_all() == 0)
    - return;
    -
    - ++data->balance;
    -
    - /*
    - * The IF needs to be cleared as well, so that the faulting
    - * instruction can run "uninterrupted". Otherwise, we might take
    - * an interrupt and start executing that before we've had a chance
    - * to hide the page again.
    - *
    - * NOTE: In the rare case of multiple faults, we must not override
    - * the original flags:
    - */
    - if (!(regs->flags & X86_EFLAGS_TF))
    - data->flags = regs->flags;
    -
    - regs->flags |= X86_EFLAGS_TF;
    - regs->flags &= ~X86_EFLAGS_IF;
    -}
    -
    -/*
    - * Called from the #DB handler.
    - */
    -void kmemcheck_hide(struct pt_regs *regs)
    -{
    - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
    - int n;
    -
    - BUG_ON(!irqs_disabled());
    -
    - if (unlikely(data->balance != 1)) {
    - kmemcheck_show_all();
    - kmemcheck_error_save_bug(regs);
    - data->n_addrs = 0;
    - data->balance = 0;
    -
    - if (!(data->flags & X86_EFLAGS_TF))
    - regs->flags &= ~X86_EFLAGS_TF;
    - if (data->flags & X86_EFLAGS_IF)
    - regs->flags |= X86_EFLAGS_IF;
    - return;
    - }
    -
    - if (kmemcheck_enabled)
    - n = kmemcheck_hide_all();
    - else
    - n = kmemcheck_show_all();
    -
    - if (n == 0)
    - return;
    -
    - --data->balance;
    -
    - data->n_addrs = 0;
    -
    - if (!(data->flags & X86_EFLAGS_TF))
    - regs->flags &= ~X86_EFLAGS_TF;
    - if (data->flags & X86_EFLAGS_IF)
    - regs->flags |= X86_EFLAGS_IF;
    -}
    -
    -void kmemcheck_show_pages(struct page *p, unsigned int n)
    -{
    - unsigned int i;
    -
    - for (i = 0; i < n; ++i) {
    - unsigned long address;
    - pte_t *pte;
    - unsigned int level;
    -
    - address = (unsigned long) page_address(&p[i]);
    - pte = lookup_address(address, &level);
    - BUG_ON(!pte);
    - BUG_ON(level != PG_LEVEL_4K);
    -
    - set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
    - set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_HIDDEN));
    - __flush_tlb_one(address);
    - }
    -}
    -
    -bool kmemcheck_page_is_tracked(struct page *p)
    -{
    - /* This will also check the "hidden" flag of the PTE. */
    - return kmemcheck_pte_lookup((unsigned long) page_address(p));
    -}
    -
    -void kmemcheck_hide_pages(struct page *p, unsigned int n)
    -{
    - unsigned int i;
    -
    - for (i = 0; i < n; ++i) {
    - unsigned long address;
    - pte_t *pte;
    - unsigned int level;
    -
    - address = (unsigned long) page_address(&p[i]);
    - pte = lookup_address(address, &level);
    - BUG_ON(!pte);
    - BUG_ON(level != PG_LEVEL_4K);
    -
    - set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
    - set_pte(pte, __pte(pte_val(*pte) | _PAGE_HIDDEN));
    - __flush_tlb_one(address);
    - }
    -}
    -
    -/* Access may NOT cross page boundary */
    -static void kmemcheck_read_strict(struct pt_regs *regs,
    - unsigned long addr, unsigned int size)
    -{
    - void *shadow;
    - enum kmemcheck_shadow status;
    -
    - shadow = kmemcheck_shadow_lookup(addr);
    - if (!shadow)
    - return;
    -
    - kmemcheck_save_addr(addr);
    - status = kmemcheck_shadow_test(shadow, size);
    - if (status == KMEMCHECK_SHADOW_INITIALIZED)
    - return;
    -
    - if (kmemcheck_enabled)
    - kmemcheck_error_save(status, addr, size, regs);
    -
    - if (kmemcheck_enabled == 2)
    - kmemcheck_enabled = 0;
    -
    - /* Don't warn about it again. */
    - kmemcheck_shadow_set(shadow, size);
    -}
    -
    -bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size)
    -{
    - enum kmemcheck_shadow status;
    - void *shadow;
    -
    - shadow = kmemcheck_shadow_lookup(addr);
    - if (!shadow)
    - return true;
    -
    - status = kmemcheck_shadow_test_all(shadow, size);
    -
    - return status == KMEMCHECK_SHADOW_INITIALIZED;
    -}
    -
    -/* Access may cross page boundary */
    -static void kmemcheck_read(struct pt_regs *regs,
    - unsigned long addr, unsigned int size)
    -{
    - unsigned long page = addr & PAGE_MASK;
    - unsigned long next_addr = addr + size - 1;
    - unsigned long next_page = next_addr & PAGE_MASK;
    -
    - if (likely(page == next_page)) {
    - kmemcheck_read_strict(regs, addr, size);
    - return;
    - }
    -
    - /*
    - * What we do is basically to split the access across the
    - * two pages and handle each part separately. Yes, this means
    - * that we may now see reads that are 3 + 5 bytes, for
    - * example (and if both are uninitialized, there will be two
    - * reports), but it makes the code a lot simpler.
    - */
    - kmemcheck_read_strict(regs, addr, next_page - addr);
    - kmemcheck_read_strict(regs, next_page, next_addr - next_page);
    -}
    -
    -static void kmemcheck_write_strict(struct pt_regs *regs,
    - unsigned long addr, unsigned int size)
    -{
    - void *shadow;
    -
    - shadow = kmemcheck_shadow_lookup(addr);
    - if (!shadow)
    - return;
    -
    - kmemcheck_save_addr(addr);
    - kmemcheck_shadow_set(shadow, size);
    -}
    -
    -static void kmemcheck_write(struct pt_regs *regs,
    - unsigned long addr, unsigned int size)
    -{
    - unsigned long page = addr & PAGE_MASK;
    - unsigned long next_addr = addr + size - 1;
    - unsigned long next_page = next_addr & PAGE_MASK;
    -
    - if (likely(page == next_page)) {
    - kmemcheck_write_strict(regs, addr, size);
    - return;
    - }
    -
    - /* See comment in kmemcheck_read(). */
    - kmemcheck_write_strict(regs, addr, next_page - addr);
    - kmemcheck_write_strict(regs, next_page, next_addr - next_page);
    -}
    -
    -/*
    - * Copying is hard. We have two addresses, each of which may be split across
    - * a page (and each page will have different shadow addresses).
    - */
    -static void kmemcheck_copy(struct pt_regs *regs,
    - unsigned long src_addr, unsigned long dst_addr, unsigned int size)
    -{
    - uint8_t shadow[8];
    - enum kmemcheck_shadow status;
    -
    - unsigned long page;
    - unsigned long next_addr;
    - unsigned long next_page;
    -
    - uint8_t *x;
    - unsigned int i;
    - unsigned int n;
    -
    - BUG_ON(size > sizeof(shadow));
    -
    - page = src_addr & PAGE_MASK;
    - next_addr = src_addr + size - 1;
    - next_page = next_addr & PAGE_MASK;
    -
    - if (likely(page == next_page)) {
    - /* Same page */
    - x = kmemcheck_shadow_lookup(src_addr);
    - if (x) {
    - kmemcheck_save_addr(src_addr);
    - for (i = 0; i < size; ++i)
    - shadow[i] = x[i];
    - } else {
    - for (i = 0; i < size; ++i)
    - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED;
    - }
    - } else {
    - n = next_page - src_addr;
    - BUG_ON(n > sizeof(shadow));
    -
    - /* First page */
    - x = kmemcheck_shadow_lookup(src_addr);
    - if (x) {
    - kmemcheck_save_addr(src_addr);
    - for (i = 0; i < n; ++i)
    - shadow[i] = x[i];
    - } else {
    - /* Not tracked */
    - for (i = 0; i < n; ++i)
    - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED;
    - }
    -
    - /* Second page */
    - x = kmemcheck_shadow_lookup(next_page);
    - if (x) {
    - kmemcheck_save_addr(next_page);
    - for (i = n; i < size; ++i)
    - shadow[i] = x[i - n];
    - } else {
    - /* Not tracked */
    - for (i = n; i < size; ++i)
    - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED;
    - }
    - }
    -
    - page = dst_addr & PAGE_MASK;
    - next_addr = dst_addr + size - 1;
    - next_page = next_addr & PAGE_MASK;
    -
    - if (likely(page == next_page)) {
    - /* Same page */
    - x = kmemcheck_shadow_lookup(dst_addr);
    - if (x) {
    - kmemcheck_save_addr(dst_addr);
    - for (i = 0; i < size; ++i) {
    - x[i] = shadow[i];
    - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED;
    - }
    - }
    - } else {
    - n = next_page - dst_addr;
    - BUG_ON(n > sizeof(shadow));
    -
    - /* First page */
    - x = kmemcheck_shadow_lookup(dst_addr);
    - if (x) {
    - kmemcheck_save_addr(dst_addr);
    - for (i = 0; i < n; ++i) {
    - x[i] = shadow[i];
    - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED;
    - }
    - }
    -
    - /* Second page */
    - x = kmemcheck_shadow_lookup(next_page);
    - if (x) {
    - kmemcheck_save_addr(next_page);
    - for (i = n; i < size; ++i) {
    - x[i - n] = shadow[i];
    - shadow[i] = KMEMCHECK_SHADOW_INITIALIZED;
    - }
    - }
    - }
    -
    - status = kmemcheck_shadow_test(shadow, size);
    - if (status == KMEMCHECK_SHADOW_INITIALIZED)
    - return;
    -
    - if (kmemcheck_enabled)
    - kmemcheck_error_save(status, src_addr, size, regs);
    -
    - if (kmemcheck_enabled == 2)
    - kmemcheck_enabled = 0;
    -}
    -
    -enum kmemcheck_method {
    - KMEMCHECK_READ,
    - KMEMCHECK_WRITE,
    -};
    -
    -static void kmemcheck_access(struct pt_regs *regs,
    - unsigned long fallback_address, enum kmemcheck_method fallback_method)
    -{
    - const uint8_t *insn;
    - const uint8_t *insn_primary;
    - unsigned int size;
    -
    - struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
    -
    - /* Recursive fault -- ouch. */
    - if (data->busy) {
    - kmemcheck_show_addr(fallback_address);
    - kmemcheck_error_save_bug(regs);
    - return;
    - }
    -
    - data->busy = true;
    -
    - insn = (const uint8_t *) regs->ip;
    - insn_primary = kmemcheck_opcode_get_primary(insn);
    -
    - kmemcheck_opcode_decode(insn, &size);
    -
    - switch (insn_primary[0]) {
    -#ifdef CONFIG_KMEMCHECK_BITOPS_OK
    - /* AND, OR, XOR */
    - /*
    - * Unfortunately, these instructions have to be excluded from
    - * our regular checking since they access only some (and not
    - * all) bits. This clears out "bogus" bitfield-access warnings.
    - */
    - case 0x80:
    - case 0x81:
    - case 0x82:
    - case 0x83:
    - switch ((insn_primary[1] >> 3) & 7) {
    - /* OR */
    - case 1:
    - /* AND */
    - case 4:
    - /* XOR */
    - case 6:
    - kmemcheck_write(regs, fallback_address, size);
    - goto out;
    -
    - /* ADD */
    - case 0:
    - /* ADC */
    - case 2:
    - /* SBB */
    - case 3:
    - /* SUB */
    - case 5:
    - /* CMP */
    - case 7:
    - break;
    - }
    - break;
    -#endif
    -
    - /* MOVS, MOVSB, MOVSW, MOVSD */
    - case 0xa4:
    - case 0xa5:
    - /*
    - * These instructions are special because they take two
    - * addresses, but we only get one page fault.
    - */
    - kmemcheck_copy(regs, regs->si, regs->di, size);
    - goto out;
    -
    - /* CMPS, CMPSB, CMPSW, CMPSD */
    - case 0xa6:
    - case 0xa7:
    - kmemcheck_read(regs, regs->si, size);
    - kmemcheck_read(regs, regs->di, size);
    - goto out;
    - }
    -
    - /*
    - * If the opcode isn't special in any way, we use the data from the
    - * page fault handler to determine the address and type of memory
    - * access.
    - */
    - switch (fallback_method) {
    - case KMEMCHECK_READ:
    - kmemcheck_read(regs, fallback_address, size);
    - goto out;
    - case KMEMCHECK_WRITE:
    - kmemcheck_write(regs, fallback_address, size);
    - goto out;
    - }
    -
    -out:
    - data->busy = false;
    -}
    -
    -bool kmemcheck_fault(struct pt_regs *regs, unsigned long address,
    - unsigned long error_code)
    -{
    - pte_t *pte;
    -
    - /*
    - * XXX: Is it safe to assume that memory accesses from virtual 86
    - * mode or non-kernel code segments will _never_ access kernel
    - * memory (e.g. tracked pages)? For now, we need this to avoid
    - * invoking kmemcheck for PnP BIOS calls.
    - */
    - if (regs->flags & X86_VM_MASK)
    - return false;
    - if (regs->cs != __KERNEL_CS)
    - return false;
    -
    - pte = kmemcheck_pte_lookup(address);
    - if (!pte)
    - return false;
    -
    - WARN_ON_ONCE(in_nmi());
    -
    - if (error_code & 2)
    - kmemcheck_access(regs, address, KMEMCHECK_WRITE);
    - else
    - kmemcheck_access(regs, address, KMEMCHECK_READ);
    -
    - kmemcheck_show(regs);
    - return true;
    -}
    -
    -bool kmemcheck_trap(struct pt_regs *regs)
    -{
    - if (!kmemcheck_active(regs))
    - return false;
    -
    - /* We're done. */
    - kmemcheck_hide(regs);
    - return true;
    -}
    diff --git a/arch/x86/mm/kmemcheck/opcode.c b/arch/x86/mm/kmemcheck/opcode.c
    deleted file mode 100644
    index 324aa3f07237..000000000000
    --- a/arch/x86/mm/kmemcheck/opcode.c
    +++ /dev/null
    @@ -1,106 +0,0 @@
    -#include <linux/types.h>
    -
    -#include "opcode.h"
    -
    -static bool opcode_is_prefix(uint8_t b)
    -{
    - return
    - /* Group 1 */
    - b == 0xf0 || b == 0xf2 || b == 0xf3
    - /* Group 2 */
    - || b == 0x2e || b == 0x36 || b == 0x3e || b == 0x26
    - || b == 0x64 || b == 0x65
    - /* Group 3 */
    - || b == 0x66
    - /* Group 4 */
    - || b == 0x67;
    -}
    -
    -#ifdef CONFIG_X86_64
    -static bool opcode_is_rex_prefix(uint8_t b)
    -{
    - return (b & 0xf0) == 0x40;
    -}
    -#else
    -static bool opcode_is_rex_prefix(uint8_t b)
    -{
    - return false;
    -}
    -#endif
    -
    -#define REX_W (1 << 3)
    -
    -/*
    - * This is a VERY crude opcode decoder. We only need to find the size of the
    - * load/store that caused our #PF and this should work for all the opcodes
    - * that we care about. Moreover, the ones who invented this instruction set
    - * should be shot.
    - */
    -void kmemcheck_opcode_decode(const uint8_t *op, unsigned int *size)
    -{
    - /* Default operand size */
    - int operand_size_override = 4;
    -
    - /* prefixes */
    - for (; opcode_is_prefix(*op); ++op) {
    - if (*op == 0x66)
    - operand_size_override = 2;
    - }
    -
    - /* REX prefix */
    - if (opcode_is_rex_prefix(*op)) {
    - uint8_t rex = *op;
    -
    - ++op;
    - if (rex & REX_W) {
    - switch (*op) {
    - case 0x63:
    - *size = 4;
    - return;
    - case 0x0f:
    - ++op;
    -
    - switch (*op) {
    - case 0xb6:
    - case 0xbe:
    - *size = 1;
    - return;
    - case 0xb7:
    - case 0xbf:
    - *size = 2;
    - return;
    - }
    -
    - break;
    - }
    -
    - *size = 8;
    - return;
    - }
    - }
    -
    - /* escape opcode */
    - if (*op == 0x0f) {
    - ++op;
    -
    - /*
    - * This is move with zero-extend and sign-extend, respectively;
    - * we don't have to think about 0xb6/0xbe, because this is
    - * already handled in the conditional below.
    - */
    - if (*op == 0xb7 || *op == 0xbf)
    - operand_size_override = 2;
    - }
    -
    - *size = (*op & 1) ? operand_size_override : 1;
    -}
    -
    -const uint8_t *kmemcheck_opcode_get_primary(const uint8_t *op)
    -{
    - /* skip prefixes */
    - while (opcode_is_prefix(*op))
    - ++op;
    - if (opcode_is_rex_prefix(*op))
    - ++op;
    - return op;
    -}
    diff --git a/arch/x86/mm/kmemcheck/opcode.h b/arch/x86/mm/kmemcheck/opcode.h
    deleted file mode 100644
    index 6956aad66b5b..000000000000
    --- a/arch/x86/mm/kmemcheck/opcode.h
    +++ /dev/null
    @@ -1,9 +0,0 @@
    -#ifndef ARCH__X86__MM__KMEMCHECK__OPCODE_H
    -#define ARCH__X86__MM__KMEMCHECK__OPCODE_H
    -
    -#include <linux/types.h>
    -
    -void kmemcheck_opcode_decode(const uint8_t *op, unsigned int *size);
    -const uint8_t *kmemcheck_opcode_get_primary(const uint8_t *op);
    -
    -#endif
    diff --git a/arch/x86/mm/kmemcheck/pte.c b/arch/x86/mm/kmemcheck/pte.c
    deleted file mode 100644
    index 4ead26eeaf96..000000000000
    --- a/arch/x86/mm/kmemcheck/pte.c
    +++ /dev/null
    @@ -1,22 +0,0 @@
    -#include <linux/mm.h>
    -
    -#include <asm/pgtable.h>
    -
    -#include "pte.h"
    -
    -pte_t *kmemcheck_pte_lookup(unsigned long address)
    -{
    - pte_t *pte;
    - unsigned int level;
    -
    - pte = lookup_address(address, &level);
    - if (!pte)
    - return NULL;
    - if (level != PG_LEVEL_4K)
    - return NULL;
    - if (!pte_hidden(*pte))
    - return NULL;
    -
    - return pte;
    -}
    -
    diff --git a/arch/x86/mm/kmemcheck/pte.h b/arch/x86/mm/kmemcheck/pte.h
    deleted file mode 100644
    index 9f5966456492..000000000000
    --- a/arch/x86/mm/kmemcheck/pte.h
    +++ /dev/null
    @@ -1,10 +0,0 @@
    -#ifndef ARCH__X86__MM__KMEMCHECK__PTE_H
    -#define ARCH__X86__MM__KMEMCHECK__PTE_H
    -
    -#include <linux/mm.h>
    -
    -#include <asm/pgtable.h>
    -
    -pte_t *kmemcheck_pte_lookup(unsigned long address);
    -
    -#endif
    diff --git a/arch/x86/mm/kmemcheck/selftest.c b/arch/x86/mm/kmemcheck/selftest.c
    deleted file mode 100644
    index aef7140c0063..000000000000
    --- a/arch/x86/mm/kmemcheck/selftest.c
    +++ /dev/null
    @@ -1,70 +0,0 @@
    -#include <linux/bug.h>
    -#include <linux/kernel.h>
    -
    -#include "opcode.h"
    -#include "selftest.h"
    -
    -struct selftest_opcode {
    - unsigned int expected_size;
    - const uint8_t *insn;
    - const char *desc;
    -};
    -
    -static const struct selftest_opcode selftest_opcodes[] = {
    - /* REP MOVS */
    - {1, "\xf3\xa4", "rep movsb <mem8>, <mem8>"},
    - {4, "\xf3\xa5", "rep movsl <mem32>, <mem32>"},
    -
    - /* MOVZX / MOVZXD */
    - {1, "\x66\x0f\xb6\x51\xf8", "movzwq <mem8>, <reg16>"},
    - {1, "\x0f\xb6\x51\xf8", "movzwq <mem8>, <reg32>"},
    -
    - /* MOVSX / MOVSXD */
    - {1, "\x66\x0f\xbe\x51\xf8", "movswq <mem8>, <reg16>"},
    - {1, "\x0f\xbe\x51\xf8", "movswq <mem8>, <reg32>"},
    -
    -#ifdef CONFIG_X86_64
    - /* MOVZX / MOVZXD */
    - {1, "\x49\x0f\xb6\x51\xf8", "movzbq <mem8>, <reg64>"},
    - {2, "\x49\x0f\xb7\x51\xf8", "movzbq <mem16>, <reg64>"},
    -
    - /* MOVSX / MOVSXD */
    - {1, "\x49\x0f\xbe\x51\xf8", "movsbq <mem8>, <reg64>"},
    - {2, "\x49\x0f\xbf\x51\xf8", "movsbq <mem16>, <reg64>"},
    - {4, "\x49\x63\x51\xf8", "movslq <mem32>, <reg64>"},
    -#endif
    -};
    -
    -static bool selftest_opcode_one(const struct selftest_opcode *op)
    -{
    - unsigned size;
    -
    - kmemcheck_opcode_decode(op->insn, &size);
    -
    - if (size == op->expected_size)
    - return true;
    -
    - printk(KERN_WARNING "kmemcheck: opcode %s: expected size %d, got %d\n",
    - op->desc, op->expected_size, size);
    - return false;
    -}
    -
    -static bool selftest_opcodes_all(void)
    -{
    - bool pass = true;
    - unsigned int i;
    -
    - for (i = 0; i < ARRAY_SIZE(selftest_opcodes); ++i)
    - pass = pass && selftest_opcode_one(&selftest_opcodes[i]);
    -
    - return pass;
    -}
    -
    -bool kmemcheck_selftest(void)
    -{
    - bool pass = true;
    -
    - pass = pass && selftest_opcodes_all();
    -
    - return pass;
    -}
    diff --git a/arch/x86/mm/kmemcheck/selftest.h b/arch/x86/mm/kmemcheck/selftest.h
    deleted file mode 100644
    index 8fed4fe11f95..000000000000
    --- a/arch/x86/mm/kmemcheck/selftest.h
    +++ /dev/null
    @@ -1,6 +0,0 @@
    -#ifndef ARCH_X86_MM_KMEMCHECK_SELFTEST_H
    -#define ARCH_X86_MM_KMEMCHECK_SELFTEST_H
    -
    -bool kmemcheck_selftest(void);
    -
    -#endif
    diff --git a/arch/x86/mm/kmemcheck/shadow.c b/arch/x86/mm/kmemcheck/shadow.c
    deleted file mode 100644
    index c2638a7d2c10..000000000000
    --- a/arch/x86/mm/kmemcheck/shadow.c
    +++ /dev/null
    @@ -1,173 +0,0 @@
    -#include <linux/kmemcheck.h>
    -#include <linux/export.h>
    -#include <linux/mm.h>
    -
    -#include <asm/page.h>
    -#include <asm/pgtable.h>
    -
    -#include "pte.h"
    -#include "shadow.h"
    -
    -/*
    - * Return the shadow address for the given address. Returns NULL if the
    - * address is not tracked.
    - *
    - * We need to be extremely careful not to follow any invalid pointers,
    - * because this function can be called for *any* possible address.
    - */
    -void *kmemcheck_shadow_lookup(unsigned long address)
    -{
    - pte_t *pte;
    - struct page *page;
    -
    - if (!virt_addr_valid(address))
    - return NULL;
    -
    - pte = kmemcheck_pte_lookup(address);
    - if (!pte)
    - return NULL;
    -
    - page = virt_to_page(address);
    - if (!page->shadow)
    - return NULL;
    - return page->shadow + (address & (PAGE_SIZE - 1));
    -}
    -
    -static void mark_shadow(void *address, unsigned int n,
    - enum kmemcheck_shadow status)
    -{
    - unsigned long addr = (unsigned long) address;
    - unsigned long last_addr = addr + n - 1;
    - unsigned long page = addr & PAGE_MASK;
    - unsigned long last_page = last_addr & PAGE_MASK;
    - unsigned int first_n;
    - void *shadow;
    -
    - /* If the memory range crosses a page boundary, stop there. */
    - if (page == last_page)
    - first_n = n;
    - else
    - first_n = page + PAGE_SIZE - addr;
    -
    - shadow = kmemcheck_shadow_lookup(addr);
    - if (shadow)
    - memset(shadow, status, first_n);
    -
    - addr += first_n;
    - n -= first_n;
    -
    - /* Do full-page memset()s. */
    - while (n >= PAGE_SIZE) {
    - shadow = kmemcheck_shadow_lookup(addr);
    - if (shadow)
    - memset(shadow, status, PAGE_SIZE);
    -
    - addr += PAGE_SIZE;
    - n -= PAGE_SIZE;
    - }
    -
    - /* Do the remaining page, if any. */
    - if (n > 0) {
    - shadow = kmemcheck_shadow_lookup(addr);
    - if (shadow)
    - memset(shadow, status, n);
    - }
    -}
    -
    -void kmemcheck_mark_unallocated(void *address, unsigned int n)
    -{
    - mark_shadow(address, n, KMEMCHECK_SHADOW_UNALLOCATED);
    -}
    -
    -void kmemcheck_mark_uninitialized(void *address, unsigned int n)
    -{
    - mark_shadow(address, n, KMEMCHECK_SHADOW_UNINITIALIZED);
    -}
    -
    -/*
    - * Fill the shadow memory of the given address such that the memory at that
    - * address is marked as being initialized.
    - */
    -void kmemcheck_mark_initialized(void *address, unsigned int n)
    -{
    - mark_shadow(address, n, KMEMCHECK_SHADOW_INITIALIZED);
    -}
    -EXPORT_SYMBOL_GPL(kmemcheck_mark_initialized);
    -
    -void kmemcheck_mark_freed(void *address, unsigned int n)
    -{
    - mark_shadow(address, n, KMEMCHECK_SHADOW_FREED);
    -}
    -
    -void kmemcheck_mark_unallocated_pages(struct page *p, unsigned int n)
    -{
    - unsigned int i;
    -
    - for (i = 0; i < n; ++i)
    - kmemcheck_mark_unallocated(page_address(&p[i]), PAGE_SIZE);
    -}
    -
    -void kmemcheck_mark_uninitialized_pages(struct page *p, unsigned int n)
    -{
    - unsigned int i;
    -
    - for (i = 0; i < n; ++i)
    - kmemcheck_mark_uninitialized(page_address(&p[i]), PAGE_SIZE);
    -}
    -
    -void kmemcheck_mark_initialized_pages(struct page *p, unsigned int n)
    -{
    - unsigned int i;
    -
    - for (i = 0; i < n; ++i)
    - kmemcheck_mark_initialized(page_address(&p[i]), PAGE_SIZE);
    -}
    -
    -enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size)
    -{
    -#ifdef CONFIG_KMEMCHECK_PARTIAL_OK
    - uint8_t *x;
    - unsigned int i;
    -
    - x = shadow;
    -
    - /*
    - * Make sure _some_ bytes are initialized. Gcc frequently generates
    - * code to access neighboring bytes.
    - */
    - for (i = 0; i < size; ++i) {
    - if (x[i] == KMEMCHECK_SHADOW_INITIALIZED)
    - return x[i];
    - }
    -
    - return x[0];
    -#else
    - return kmemcheck_shadow_test_all(shadow, size);
    -#endif
    -}
    -
    -enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow, unsigned int size)
    -{
    - uint8_t *x;
    - unsigned int i;
    -
    - x = shadow;
    -
    - /* All bytes must be initialized. */
    - for (i = 0; i < size; ++i) {
    - if (x[i] != KMEMCHECK_SHADOW_INITIALIZED)
    - return x[i];
    - }
    -
    - return x[0];
    -}
    -
    -void kmemcheck_shadow_set(void *shadow, unsigned int size)
    -{
    - uint8_t *x;
    - unsigned int i;
    -
    - x = shadow;
    - for (i = 0; i < size; ++i)
    - x[i] = KMEMCHECK_SHADOW_INITIALIZED;
    -}
    diff --git a/arch/x86/mm/kmemcheck/shadow.h b/arch/x86/mm/kmemcheck/shadow.h
    deleted file mode 100644
    index ff0b2f70fbcb..000000000000
    --- a/arch/x86/mm/kmemcheck/shadow.h
    +++ /dev/null
    @@ -1,18 +0,0 @@
    -#ifndef ARCH__X86__MM__KMEMCHECK__SHADOW_H
    -#define ARCH__X86__MM__KMEMCHECK__SHADOW_H
    -
    -enum kmemcheck_shadow {
    - KMEMCHECK_SHADOW_UNALLOCATED,
    - KMEMCHECK_SHADOW_UNINITIALIZED,
    - KMEMCHECK_SHADOW_INITIALIZED,
    - KMEMCHECK_SHADOW_FREED,
    -};
    -
    -void *kmemcheck_shadow_lookup(unsigned long address);
    -
    -enum kmemcheck_shadow kmemcheck_shadow_test(void *shadow, unsigned int size);
    -enum kmemcheck_shadow kmemcheck_shadow_test_all(void *shadow,
    - unsigned int size);
    -void kmemcheck_shadow_set(void *shadow, unsigned int size);
    -
    -#endif
    diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
    index 0977317c6835..25695c3e8904 100644
    --- a/include/linux/dma-mapping.h
    +++ b/include/linux/dma-mapping.h
    @@ -8,7 +8,6 @@
    #include <linux/dma-debug.h>
    #include <linux/dma-direction.h>
    #include <linux/scatterlist.h>
    -#include <linux/kmemcheck.h>
    #include <linux/bug.h>

    /**
    @@ -205,7 +204,6 @@ static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
    const struct dma_map_ops *ops = get_dma_ops(dev);
    dma_addr_t addr;

    - kmemcheck_mark_initialized(ptr, size);
    BUG_ON(!valid_dma_direction(dir));
    addr = ops->map_page(dev, virt_to_page(ptr),
    offset_in_page(ptr), size,
    @@ -238,11 +236,8 @@ static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
    unsigned long attrs)
    {
    const struct dma_map_ops *ops = get_dma_ops(dev);
    - int i, ents;
    - struct scatterlist *s;
    + int ents;

    - for_each_sg(sg, s, nents, i)
    - kmemcheck_mark_initialized(sg_virt(s), s->length);
    BUG_ON(!valid_dma_direction(dir));
    ents = ops->map_sg(dev, sg, nents, dir, attrs);
    BUG_ON(ents < 0);
    @@ -272,7 +267,6 @@ static inline dma_addr_t dma_map_page_attrs(struct device *dev,
    const struct dma_map_ops *ops = get_dma_ops(dev);
    dma_addr_t addr;

    - kmemcheck_mark_initialized(page_address(page) + offset, size);
    BUG_ON(!valid_dma_direction(dir));
    addr = ops->map_page(dev, page, offset, size, dir, attrs);
    debug_dma_map_page(dev, page, offset, size, dir, addr, false);
    diff --git a/include/linux/gfp.h b/include/linux/gfp.h
    index db373b9d3223..c76c89586fff 100644
    --- a/include/linux/gfp.h
    +++ b/include/linux/gfp.h
    @@ -166,8 +166,6 @@ struct vm_area_struct;
    *
    * __GFP_ZERO returns a zeroed page on success.
    *
    - * __GFP_NOTRACK avoids tracking with kmemcheck.
    - *
    * __GFP_NOTRACK_FALSE_POSITIVE is an alias of __GFP_NOTRACK. It's a means of
    * distinguishing in the source between false positives and allocations that
    * cannot be supported (e.g. page tables).
    diff --git a/include/linux/kmemcheck.h b/include/linux/kmemcheck.h
    index 39f8453239f7..00a371c5a50f 100644
    --- a/include/linux/kmemcheck.h
    +++ b/include/linux/kmemcheck.h
    @@ -4,38 +4,6 @@
    #include <linux/mm_types.h>
    #include <linux/types.h>

    -#ifdef CONFIG_KMEMCHECK
    -extern int kmemcheck_enabled;
    -
    -/* The slab-related functions. */
    -void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node);
    -void kmemcheck_free_shadow(struct page *page, int order);
    -void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
    - size_t size);
    -void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size);
    -
    -void kmemcheck_pagealloc_alloc(struct page *p, unsigned int order,
    - gfp_t gfpflags);
    -
    -void kmemcheck_show_pages(struct page *p, unsigned int n);
    -void kmemcheck_hide_pages(struct page *p, unsigned int n);
    -
    -bool kmemcheck_page_is_tracked(struct page *p);
    -
    -void kmemcheck_mark_unallocated(void *address, unsigned int n);
    -void kmemcheck_mark_uninitialized(void *address, unsigned int n);
    -void kmemcheck_mark_initialized(void *address, unsigned int n);
    -void kmemcheck_mark_freed(void *address, unsigned int n);
    -
    -void kmemcheck_mark_unallocated_pages(struct page *p, unsigned int n);
    -void kmemcheck_mark_uninitialized_pages(struct page *p, unsigned int n);
    -void kmemcheck_mark_initialized_pages(struct page *p, unsigned int n);
    -
    -int kmemcheck_show_addr(unsigned long address);
    -int kmemcheck_hide_addr(unsigned long address);
    -
    -bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size);
    -
    /*
    * Bitfield annotations
    *
    @@ -61,32 +29,7 @@ bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size);
    * struct a *a = kmalloc(sizeof(struct a), GFP_KERNEL);
    * kmemcheck_annotate_bitfield(a, flags);
    */
    -#define kmemcheck_bitfield_begin(name) \
    - int name##_begin[0];
    -
    -#define kmemcheck_bitfield_end(name) \
    - int name##_end[0];
    -
    -#define kmemcheck_annotate_bitfield(ptr, name) \
    - do { \
    - int _n; \
    - \
    - if (!ptr) \
    - break; \
    - \
    - _n = (long) &((ptr)->name##_end) \
    - - (long) &((ptr)->name##_begin); \
    - BUILD_BUG_ON(_n < 0); \
    - \
    - kmemcheck_mark_initialized(&((ptr)->name##_begin), _n); \
    - } while (0)
    -
    -#define kmemcheck_annotate_variable(var) \
    - do { \
    - kmemcheck_mark_initialized(&(var), sizeof(var)); \
    - } while (0) \

    -#else
    #define kmemcheck_enabled 0

    static inline void
    @@ -166,6 +109,4 @@ static inline bool kmemcheck_is_obj_initialized(unsigned long addr, size_t size)
    do { \
    } while (0)

    -#endif /* CONFIG_KMEMCHECK */
    -
    #endif /* LINUX_KMEMCHECK_H */
    diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
    index f60f45fe226f..3f4c2f982f78 100644
    --- a/include/linux/mm_types.h
    +++ b/include/linux/mm_types.h
    @@ -205,14 +205,6 @@ struct page {
    not kmapped, ie. highmem) */
    #endif /* WANT_PAGE_VIRTUAL */

    -#ifdef CONFIG_KMEMCHECK
    - /*
    - * kmemcheck wants to track the status of each byte in a page; this
    - * is a pointer to such a status block. NULL if not tracked.
    - */
    - void *shadow;
    -#endif
    -
    #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
    int _last_cpupid;
    #endif
    diff --git a/include/linux/slab.h b/include/linux/slab.h
    index 3c37a8c51921..378b51588178 100644
    --- a/include/linux/slab.h
    +++ b/include/linux/slab.h
    @@ -75,12 +75,12 @@

    #define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */

    -/* Don't track use of uninitialized memory */
    -#ifdef CONFIG_KMEMCHECK
    -# define SLAB_NOTRACK 0x01000000UL
    -#else
    -# define SLAB_NOTRACK 0x00000000UL
    -#endif
    +/*
    + * Used by kmemcheck in the past; obsolete, but kept for the sake of
    + * out-of-tree module source backwards compatibility.
    + */
    +#define SLAB_NOTRACK 0
    +
    #ifdef CONFIG_FAILSLAB
    # define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */
    #else
    diff --git a/init/main.c b/init/main.c
    index b0c11cbf5ddf..266210a551e5 100644
    --- a/init/main.c
    +++ b/init/main.c
    @@ -69,7 +69,6 @@
    #include <linux/kgdb.h>
    #include <linux/ftrace.h>
    #include <linux/async.h>
    -#include <linux/kmemcheck.h>
    #include <linux/sfi.h>
    #include <linux/shmem_fs.h>
    #include <linux/slab.h>
    diff --git a/kernel/sysctl.c b/kernel/sysctl.c
    index 8c8714fcb53c..e4fe29cea4ae 100644
    --- a/kernel/sysctl.c
    +++ b/kernel/sysctl.c
    @@ -30,7 +30,6 @@
    #include <linux/proc_fs.h>
    #include <linux/security.h>
    #include <linux/ctype.h>
    -#include <linux/kmemcheck.h>
    #include <linux/kmemleak.h>
    #include <linux/fs.h>
    #include <linux/init.h>
    @@ -1151,15 +1150,6 @@ static struct ctl_table kern_table[] = {
    .extra2 = &one_thousand,
    },
    #endif
    -#ifdef CONFIG_KMEMCHECK
    - {
    - .procname = "kmemcheck",
    - .data = &kmemcheck_enabled,
    - .maxlen = sizeof(int),
    - .mode = 0644,
    - .proc_handler = proc_dointvec,
    - },
    -#endif
    {
    .procname = "panic_on_warn",
    .data = &panic_on_warn,
    diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
    index fa16c0f82d6e..ad81261e83db 100644
    --- a/lib/Kconfig.debug
    +++ b/lib/Kconfig.debug
    @@ -499,7 +499,7 @@ config DEBUG_OBJECTS_ENABLE_DEFAULT

    config DEBUG_SLAB
    bool "Debug slab memory allocations"
    - depends on DEBUG_KERNEL && SLAB && !KMEMCHECK
    + depends on DEBUG_KERNEL && SLAB
    help
    Say Y here to have the kernel do limited verification on memory
    allocation as well as poisoning memory on free to catch use of freed
    @@ -511,7 +511,7 @@ config DEBUG_SLAB_LEAK

    config SLUB_DEBUG_ON
    bool "SLUB debugging on by default"
    - depends on SLUB && SLUB_DEBUG && !KMEMCHECK
    + depends on SLUB && SLUB_DEBUG
    default n
    help
    Boot with debugging on by default. SLUB boots by default with
    @@ -725,8 +725,6 @@ config DEBUG_STACKOVERFLOW

    If in doubt, say "N".

    -source "lib/Kconfig.kmemcheck"
    -
    source "lib/Kconfig.kasan"

    endmenu # "Memory Debugging"
    diff --git a/lib/Kconfig.kmemcheck b/lib/Kconfig.kmemcheck
    deleted file mode 100644
    index 846e039a86b4..000000000000
    --- a/lib/Kconfig.kmemcheck
    +++ /dev/null
    @@ -1,94 +0,0 @@
    -config HAVE_ARCH_KMEMCHECK
    - bool
    -
    -if HAVE_ARCH_KMEMCHECK
    -
    -menuconfig KMEMCHECK
    - bool "kmemcheck: trap use of uninitialized memory"
    - depends on DEBUG_KERNEL
    - depends on !X86_USE_3DNOW
    - depends on SLUB || SLAB
    - depends on !CC_OPTIMIZE_FOR_SIZE
    - depends on !FUNCTION_TRACER
    - select FRAME_POINTER
    - select STACKTRACE
    - default n
    - help
    - This option enables tracing of dynamically allocated kernel memory
    - to see if memory is used before it has been given an initial value.
    - Be aware that this requires half of your memory for bookkeeping and
    - will insert extra code at *every* read and write to tracked memory
    - thus slow down the kernel code (but user code is unaffected).
    -
    - The kernel may be started with kmemcheck=0 or kmemcheck=1 to disable
    - or enable kmemcheck at boot-time. If the kernel is started with
    - kmemcheck=0, the large memory and CPU overhead is not incurred.
    -
    -choice
    - prompt "kmemcheck: default mode at boot"
    - depends on KMEMCHECK
    - default KMEMCHECK_ONESHOT_BY_DEFAULT
    - help
    - This option controls the default behaviour of kmemcheck when the
    - kernel boots and no kmemcheck= parameter is given.
    -
    -config KMEMCHECK_DISABLED_BY_DEFAULT
    - bool "disabled"
    - depends on KMEMCHECK
    -
    -config KMEMCHECK_ENABLED_BY_DEFAULT
    - bool "enabled"
    - depends on KMEMCHECK
    -
    -config KMEMCHECK_ONESHOT_BY_DEFAULT
    - bool "one-shot"
    - depends on KMEMCHECK
    - help
    - In one-shot mode, only the first error detected is reported before
    - kmemcheck is disabled.
    -
    -endchoice
    -
    -config KMEMCHECK_QUEUE_SIZE
    - int "kmemcheck: error queue size"
    - depends on KMEMCHECK
    - default 64
    - help
    - Select the maximum number of errors to store in the queue. Since
    - errors can occur virtually anywhere and in any context, we need a
    - temporary storage area which is guarantueed not to generate any
    - other faults. The queue will be emptied as soon as a tasklet may
    - be scheduled. If the queue is full, new error reports will be
    - lost.
    -
    -config KMEMCHECK_SHADOW_COPY_SHIFT
    - int "kmemcheck: shadow copy size (5 => 32 bytes, 6 => 64 bytes)"
    - depends on KMEMCHECK
    - range 2 8
    - default 5
    - help
    - Select the number of shadow bytes to save along with each entry of
    - the queue. These bytes indicate what parts of an allocation are
    - initialized, uninitialized, etc. and will be displayed when an
    - error is detected to help the debugging of a particular problem.
    -
    -config KMEMCHECK_PARTIAL_OK
    - bool "kmemcheck: allow partially uninitialized memory"
    - depends on KMEMCHECK
    - default y
    - help
    - This option works around certain GCC optimizations that produce
    - 32-bit reads from 16-bit variables where the upper 16 bits are
    - thrown away afterwards. This may of course also hide some real
    - bugs.
    -
    -config KMEMCHECK_BITOPS_OK
    - bool "kmemcheck: allow bit-field manipulation"
    - depends on KMEMCHECK
    - default n
    - help
    - This option silences warnings that would be generated for bit-field
    - accesses where not all the bits are initialized at the same time.
    - This may also hide some real bugs.
    -
    -endif
    diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
    index 79d0fd13b5b3..65b24c33186d 100644
    --- a/mm/Kconfig.debug
    +++ b/mm/Kconfig.debug
    @@ -11,7 +11,6 @@ config DEBUG_PAGEALLOC
    bool "Debug page memory allocations"
    depends on DEBUG_KERNEL
    depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
    - depends on !KMEMCHECK
    select PAGE_EXTENSION
    select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
    ---help---
    diff --git a/mm/Makefile b/mm/Makefile
    index 026f6a828a50..543311e74494 100644
    --- a/mm/Makefile
    +++ b/mm/Makefile
    @@ -16,7 +16,6 @@ KCOV_INSTRUMENT_slub.o := n
    KCOV_INSTRUMENT_page_alloc.o := n
    KCOV_INSTRUMENT_debug-pagealloc.o := n
    KCOV_INSTRUMENT_kmemleak.o := n
    -KCOV_INSTRUMENT_kmemcheck.o := n
    KCOV_INSTRUMENT_memcontrol.o := n
    KCOV_INSTRUMENT_mmzone.o := n
    KCOV_INSTRUMENT_vmstat.o := n
    @@ -69,7 +68,6 @@ obj-$(CONFIG_KSM) += ksm.o
    obj-$(CONFIG_PAGE_POISONING) += page_poison.o
    obj-$(CONFIG_SLAB) += slab.o
    obj-$(CONFIG_SLUB) += slub.o
    -obj-$(CONFIG_KMEMCHECK) += kmemcheck.o
    obj-$(CONFIG_KASAN) += kasan/
    obj-$(CONFIG_FAILSLAB) += failslab.o
    obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
    diff --git a/mm/kmemcheck.c b/mm/kmemcheck.c
    deleted file mode 100644
    index 5bf191756a4a..000000000000
    --- a/mm/kmemcheck.c
    +++ /dev/null
    @@ -1,125 +0,0 @@
    -#include <linux/gfp.h>
    -#include <linux/mm_types.h>
    -#include <linux/mm.h>
    -#include <linux/slab.h>
    -#include "slab.h"
    -#include <linux/kmemcheck.h>
    -
    -void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
    -{
    - struct page *shadow;
    - int pages;
    - int i;
    -
    - pages = 1 << order;
    -
    - /*
    - * With kmemcheck enabled, we need to allocate a memory area for the
    - * shadow bits as well.
    - */
    - shadow = alloc_pages_node(node, flags | __GFP_NOTRACK, order);
    - if (!shadow) {
    - if (printk_ratelimit())
    - pr_err("kmemcheck: failed to allocate shadow bitmap\n");
    - return;
    - }
    -
    - for(i = 0; i < pages; ++i)
    - page[i].shadow = page_address(&shadow[i]);
    -
    - /*
    - * Mark it as non-present for the MMU so that our accesses to
    - * this memory will trigger a page fault and let us analyze
    - * the memory accesses.
    - */
    - kmemcheck_hide_pages(page, pages);
    -}
    -
    -void kmemcheck_free_shadow(struct page *page, int order)
    -{
    - struct page *shadow;
    - int pages;
    - int i;
    -
    - if (!kmemcheck_page_is_tracked(page))
    - return;
    -
    - pages = 1 << order;
    -
    - kmemcheck_show_pages(page, pages);
    -
    - shadow = virt_to_page(page[0].shadow);
    -
    - for(i = 0; i < pages; ++i)
    - page[i].shadow = NULL;
    -
    - __free_pages(shadow, order);
    -}
    -
    -void kmemcheck_slab_alloc(struct kmem_cache *s, gfp_t gfpflags, void *object,
    - size_t size)
    -{
    - if (unlikely(!object)) /* Skip object if allocation failed */
    - return;
    -
    - /*
    - * Has already been memset(), which initializes the shadow for us
    - * as well.
    - */
    - if (gfpflags & __GFP_ZERO)
    - return;
    -
    - /* No need to initialize the shadow of a non-tracked slab. */
    - if (s->flags & SLAB_NOTRACK)
    - return;
    -
    - if (!kmemcheck_enabled || gfpflags & __GFP_NOTRACK) {
    - /*
    - * Allow notracked objects to be allocated from
    - * tracked caches. Note however that these objects
    - * will still get page faults on access, they just
    - * won't ever be flagged as uninitialized. If page
    - * faults are not acceptable, the slab cache itself
    - * should be marked NOTRACK.
    - */
    - kmemcheck_mark_initialized(object, size);
    - } else if (!s->ctor) {
    - /*
    - * New objects should be marked uninitialized before
    - * they're returned to the called.
    - */
    - kmemcheck_mark_uninitialized(object, size);
    - }
    -}
    -
    -void kmemcheck_slab_free(struct kmem_cache *s, void *object, size_t size)
    -{
    - /* TODO: RCU freeing is unsupported for now; hide false positives. */
    - if (!s->ctor && !(s->flags & SLAB_DESTROY_BY_RCU))
    - kmemcheck_mark_freed(object, size);
    -}
    -
    -void kmemcheck_pagealloc_alloc(struct page *page, unsigned int order,
    - gfp_t gfpflags)
    -{
    - int pages;
    -
    - if (gfpflags & (__GFP_HIGHMEM | __GFP_NOTRACK))
    - return;
    -
    - pages = 1 << order;
    -
    - /*
    - * NOTE: We choose to track GFP_ZERO pages too; in fact, they
    - * can become uninitialized by copying uninitialized memory
    - * into them.
    - */
    -
    - /* XXX: Can use zone->node for node? */
    - kmemcheck_alloc_shadow(page, order, gfpflags, -1);
    -
    - if (gfpflags & __GFP_ZERO)
    - kmemcheck_mark_initialized_pages(page, pages);
    - else
    - kmemcheck_mark_uninitialized_pages(page, pages);
    -}
    diff --git a/mm/page_alloc.c b/mm/page_alloc.c
    index 07efbc3a8656..9c51972f4168 100644
    --- a/mm/page_alloc.c
    +++ b/mm/page_alloc.c
    @@ -24,7 +24,6 @@
    #include <linux/memblock.h>
    #include <linux/compiler.h>
    #include <linux/kernel.h>
    -#include <linux/kmemcheck.h>
    #include <linux/kasan.h>
    #include <linux/module.h>
    #include <linux/suspend.h>
    @@ -1001,7 +1000,6 @@ static __always_inline bool free_pages_prepare(struct page *page,
    VM_BUG_ON_PAGE(PageTail(page), page);

    trace_mm_page_free(page, order);
    - kmemcheck_free_shadow(page, order);

    /*
    * Check tail pages before head page information is cleared to
    @@ -2558,15 +2556,6 @@ void split_page(struct page *page, unsigned int order)
    VM_BUG_ON_PAGE(PageCompound(page), page);
    VM_BUG_ON_PAGE(!page_count(page), page);

    -#ifdef CONFIG_KMEMCHECK
    - /*
    - * Split shadow pages too, because free(page[0]) would
    - * otherwise free the whole shadow.
    - */
    - if (kmemcheck_page_is_tracked(page))
    - split_page(virt_to_page(page[0].shadow), order);
    -#endif
    -
    for (i = 1; i < (1 << order); i++)
    set_page_refcounted(page + i);
    split_page_owner(page, order);
    @@ -3993,9 +3982,6 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
    page = NULL;
    }

    - if (kmemcheck_enabled && page)
    - kmemcheck_pagealloc_alloc(page, order, gfp_mask);
    -
    trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);

    return page;
    diff --git a/mm/slab.c b/mm/slab.c
    index 807d86c76908..2a20911622dd 100644
    --- a/mm/slab.c
    +++ b/mm/slab.c
    @@ -113,7 +113,6 @@
    #include <linux/rtmutex.h>
    #include <linux/reciprocal_div.h>
    #include <linux/debugobjects.h>
    -#include <linux/kmemcheck.h>
    #include <linux/memory.h>
    #include <linux/prefetch.h>
    #include <linux/sched/task_stack.h>
    @@ -1436,15 +1435,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
    if (sk_memalloc_socks() && page_is_pfmemalloc(page))
    SetPageSlabPfmemalloc(page);

    - if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
    - kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid);
    -
    - if (cachep->ctor)
    - kmemcheck_mark_uninitialized_pages(page, nr_pages);
    - else
    - kmemcheck_mark_unallocated_pages(page, nr_pages);
    - }
    -
    return page;
    }

    @@ -1456,8 +1446,6 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
    int order = cachep->gfporder;
    unsigned long nr_freed = (1 << order);

    - kmemcheck_free_shadow(page, order);
    -
    if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
    sub_zone_page_state(page_zone(page),
    NR_SLAB_RECLAIMABLE, nr_freed);
    @@ -3523,8 +3511,6 @@ void ___cache_free(struct kmem_cache *cachep, void *objp,
    kmemleak_free_recursive(objp, cachep->flags);
    objp = cache_free_debugcheck(cachep, objp, caller);

    - kmemcheck_slab_free(cachep, objp, cachep->object_size);
    -
    /*
    * Skip calling cache_free_alien() when the platform is not numa.
    * This will avoid cache misses that happen while accessing slabp (which
    diff --git a/mm/slab.h b/mm/slab.h
    index 65e7c3fcac72..f701ab7e0107 100644
    --- a/mm/slab.h
    +++ b/mm/slab.h
    @@ -39,7 +39,6 @@ struct kmem_cache {

    #include <linux/memcontrol.h>
    #include <linux/fault-inject.h>
    -#include <linux/kmemcheck.h>
    #include <linux/kasan.h>
    #include <linux/kmemleak.h>
    #include <linux/random.h>
    @@ -450,7 +449,6 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
    for (i = 0; i < size; i++) {
    void *object = p[i];

    - kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
    kmemleak_alloc_recursive(object, s->object_size, 1,
    s->flags, flags);
    kasan_slab_alloc(s, object, flags);
    diff --git a/mm/slub.c b/mm/slub.c
    index 7f4bc7027ed5..f77d0ac055ea 100644
    --- a/mm/slub.c
    +++ b/mm/slub.c
    @@ -21,7 +21,6 @@
    #include <linux/notifier.h>
    #include <linux/seq_file.h>
    #include <linux/kasan.h>
    -#include <linux/kmemcheck.h>
    #include <linux/cpu.h>
    #include <linux/cpuset.h>
    #include <linux/mempolicy.h>
    @@ -1336,12 +1335,11 @@ static inline void *slab_free_hook(struct kmem_cache *s, void *x)
    * So in order to make the debug calls that expect irqs to be
    * disabled we need to disable interrupts temporarily.
    */
    -#if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
    +#if defined(CONFIG_LOCKDEP)
    {
    unsigned long flags;

    local_irq_save(flags);
    - kmemcheck_slab_free(s, x, s->object_size);
    debug_check_no_locks_freed(x, s->object_size);
    local_irq_restore(flags);
    }
    @@ -1365,8 +1363,7 @@ static inline void slab_free_freelist_hook(struct kmem_cache *s,
    * Compiler cannot detect this function can be removed if slab_free_hook()
    * evaluates to nothing. Thus, catch all relevant config debug options here.
    */
    -#if defined(CONFIG_KMEMCHECK) || \
    - defined(CONFIG_LOCKDEP) || \
    +#if defined(CONFIG_LOCKDEP) || \
    defined(CONFIG_DEBUG_KMEMLEAK) || \
    defined(CONFIG_DEBUG_OBJECTS_FREE) || \
    defined(CONFIG_KASAN)
    @@ -1562,22 +1559,6 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
    stat(s, ORDER_FALLBACK);
    }

    - if (kmemcheck_enabled &&
    - !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
    - int pages = 1 << oo_order(oo);
    -
    - kmemcheck_alloc_shadow(page, oo_order(oo), alloc_gfp, node);
    -
    - /*
    - * Objects from caches that have a constructor don't get
    - * cleared when they're allocated, so we need to do it here.
    - */
    - if (s->ctor)
    - kmemcheck_mark_uninitialized_pages(page, pages);
    - else
    - kmemcheck_mark_unallocated_pages(page, pages);
    - }
    -
    page->objects = oo_objects(oo);

    order = compound_order(page);
    @@ -1653,8 +1634,6 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
    check_object(s, page, p, SLUB_RED_INACTIVE);
    }

    - kmemcheck_free_shadow(page, compound_order(page));
    -
    mod_zone_page_state(page_zone(page),
    (s->flags & SLAB_RECLAIM_ACCOUNT) ?
    NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
    --
    2.12.0.rc0
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      Last update: 2017-09-30 19:44    [W:4.733 / U:0.044 seconds]
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