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Subject[PATCH 09/11] x86/fault: Rename no_context() to kernelmode_fixup_or_oops()
Date
The name no_context() has never been very clear.  It's only called for
faults from kernel mode, so rename it and change the no-longer-useful
user_mode(regs) check to a WARN_ON_ONCE.

Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/mm/fault.c | 28 ++++++++++------------------
1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 177b612c7f33..04cc98ec2423 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -693,17 +693,10 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code,
}

static noinline void
-no_context(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, int signal, int si_code)
+kernelmode_fixup_or_oops(struct pt_regs *regs, unsigned long error_code,
+ unsigned long address, int signal, int si_code)
{
- if (user_mode(regs)) {
- /*
- * This is an implicit supervisor-mode access from user
- * mode. Bypass all the kernel-mode recovery code and just
- * OOPS.
- */
- goto oops;
- }
+ WARN_ON_ONCE(user_mode(regs));

/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs, X86_TRAP_PF, error_code, address)) {
@@ -743,7 +736,6 @@ no_context(struct pt_regs *regs, unsigned long error_code,
if (is_prefetch(regs, error_code, address))
return;

-oops:
page_fault_oops(regs, error_code, address);
}

@@ -790,7 +782,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
struct task_struct *tsk = current;

if (!user_mode(regs)) {
- no_context(regs, error_code, address, pkey, si_code);
+ kernelmode_fixup_or_oops(regs, error_code, address, pkey, si_code);
return;
}

@@ -922,7 +914,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
{
/* Kernel mode? Handle exceptions or die: */
if (!user_mode(regs)) {
- no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);
+ kernelmode_fixup_or_oops(regs, error_code, address, SIGBUS, BUS_ADRERR);
return;
}

@@ -1382,8 +1374,8 @@ void do_user_addr_fault(struct pt_regs *regs,
* has unlocked the mm for us if we get here.
*/
if (!user_mode(regs))
- no_context(regs, error_code, address, SIGBUS,
- BUS_ADRERR);
+ kernelmode_fixup_or_oops(regs, error_code, address,
+ SIGBUS, BUS_ADRERR);
return;
}

@@ -1403,15 +1395,15 @@ void do_user_addr_fault(struct pt_regs *regs,
return;

if (fatal_signal_pending(current) && !user_mode(regs)) {
- no_context(regs, error_code, address, 0, 0);
+ kernelmode_fixup_or_oops(regs, error_code, address, 0, 0);
return;
}

if (fault & VM_FAULT_OOM) {
/* Kernel mode? Handle exceptions or die: */
if (!user_mode(regs)) {
- no_context(regs, error_code, address,
- SIGSEGV, SEGV_MAPERR);
+ kernelmode_fixup_or_oops(regs, error_code, address,
+ SIGSEGV, SEGV_MAPERR);
return;
}

--
2.29.2
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