Author: Ingo Molnar <mingo@xxxxxxx> AuthorDate: Fri, 20 Feb 2009 22:18:08 +0100 Commit: Ingo Molnar <mingo@xxxxxxx> CommitDate: Sat, 21 Feb 2009 00:09:41 +0100 x86, mm: fault.c, enable PF_RSVD checks on 32-bit too Impact: improve page fault handling robustness The 'PF_RSVD' flag (bit 3) of the page-fault error_code is a relatively recent addition to x86 CPUs, so the 32-bit do_fault() implementation never had it. This flag gets set when the CPU detects nonzero values in any reserved bits of the page directory entries. Extend the existing 64-bit check for PF_RSVD in do_page_fault() to 32-bit too. If we detect such a fault then we print a more informative oops and the pagetables. This unifies the code some more, removes an ugly #ifdef and improves the 32-bit page fault code robustness a bit. It slightly increases the 32-bit kernel text size. Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- arch/x86/mm/fault.c | 4 ---- 1 files changed, 0 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 7dc0615..3e36614 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -477,7 +477,6 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, dump_pagetable(address); } -#ifdef CONFIG_X86_64 static noinline void pgtable_bad(struct pt_regs *regs, unsigned long error_code, unsigned long address) @@ -503,7 +502,6 @@ pgtable_bad(struct pt_regs *regs, unsigned long error_code, oops_end(flags, regs, sig); } -#endif static noinline void no_context(struct pt_regs *regs, unsigned long error_code, @@ -1015,10 +1013,8 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) local_irq_enable(); } -#ifdef CONFIG_X86_64 if (unlikely(error_code & PF_RSVD)) pgtable_bad(regs, error_code, address); -#endif /* * If we're in an interrupt, have no user context or are running -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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