lkml.org 
[lkml]   [2018]   [Aug]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/pti] x86/mm/init: Add helper for freeing kernel image pages
Commit-ID:  6ea2738e0ca0e626c75202fb051c1e88d7a950fa
Gitweb: https://git.kernel.org/tip/6ea2738e0ca0e626c75202fb051c1e88d7a950fa
Author: Dave Hansen <dave.hansen@linux.intel.com>
AuthorDate: Thu, 2 Aug 2018 15:58:29 -0700
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sun, 5 Aug 2018 22:21:03 +0200

x86/mm/init: Add helper for freeing kernel image pages

When chunks of the kernel image are freed, free_init_pages() is used
directly. Consolidate the three sites that do this. Also update the
string to give an incrementally better description of that memory versus
what was there before.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: hughd@google.com
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225829.FE0E32EA@viggo.jf.intel.com

---
arch/x86/include/asm/processor.h | 1 +
arch/x86/mm/init.c | 15 ++++++++++++---
arch/x86/mm/init_64.c | 4 ++--
3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index cfd29ee8c3da..59663c08c949 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -966,6 +966,7 @@ static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)

extern unsigned long arch_align_stack(unsigned long sp);
extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
+extern void free_kernel_image_pages(void *begin, void *end);

void default_idle(void);
#ifdef CONFIG_XEN
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index cee58a972cb2..bc11dedffc45 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -773,13 +773,22 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
}
}

+/*
+ * begin/end can be in the direct map or the "high kernel mapping"
+ * used for the kernel image only. free_init_pages() will do the
+ * right thing for either kind of address.
+ */
+void free_kernel_image_pages(void *begin, void *end)
+{
+ free_init_pages("unused kernel image",
+ (unsigned long)begin, (unsigned long)end);
+}
+
void __ref free_initmem(void)
{
e820__reallocate_tables();

- free_init_pages("unused kernel",
- (unsigned long)(&__init_begin),
- (unsigned long)(&__init_end));
+ free_kernel_image_pages(&__init_begin, &__init_end);
}

#ifdef CONFIG_BLK_DEV_INITRD
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 73158655c4a7..68c292cb1ebf 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1283,8 +1283,8 @@ void mark_rodata_ro(void)
set_memory_ro(start, (end-start) >> PAGE_SHIFT);
#endif

- free_init_pages("unused kernel", text_end, rodata_start);
- free_init_pages("unused kernel", rodata_end, _sdata);
+ free_kernel_image_pages((void *)text_end, (void *)rodata_start);
+ free_kernel_image_pages((void *)rodata_end, (void *)_sdata);

debug_checkwx();

\
 
 \ /
  Last update: 2018-08-05 22:33    [W:0.111 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site