diff options
| author | Vegard Nossum <vegard.nossum@gmail.com> | 2008-04-04 00:53:23 +0200 |
|---|---|---|
| committer | Vegard Nossum <vegard.nossum@gmail.com> | 2009-06-15 12:40:02 +0200 |
| commit | f85612967c93b67b10dd240e3e8bf8a0eee9def7 (patch) | |
| tree | 184a70bc888b35235ee0b1805a06f90fd45295d8 /arch/x86/mm | |
| parent | f8b4ece2a94693b7d2dd32ea716cb92545b5dce6 (diff) | |
x86: add hooks for kmemcheck
The hooks that we modify are:
- Page fault handler (to handle kmemcheck faults)
- Debug exception handler (to hide pages after single-stepping
the instruction that caused the page fault)
Also redefine memset() to use the optimized version if kmemcheck is
enabled.
(Thanks to Pekka Enberg for minimizing the impact on the page fault
handler.)
As kmemcheck doesn't handle MMX/SSE instructions (yet), we also disable
the optimized xor code, and rely instead on the generic C implementation
in order to avoid false-positive warnings.
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
[whitespace fixlet]
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/fault.c | 18 | ||||
| -rw-r--r-- | arch/x86/mm/init.c | 2 | ||||
| -rw-r--r-- | arch/x86/mm/init_32.c | 2 |
3 files changed, 17 insertions, 5 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index c6acc632637..baa0e86adfb 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -14,6 +14,7 @@ #include <asm/traps.h> /* dotraplinkage, ... */ #include <asm/pgalloc.h> /* pgd_*(), ... */ +#include <asm/kmemcheck.h> /* kmemcheck_*(), ... */ /* * Page fault error code bits: @@ -956,6 +957,13 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code) /* Get the faulting address: */ address = read_cr2(); + /* + * 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); + if (unlikely(kmmio_fault(regs, address))) return; @@ -973,9 +981,13 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code) * protection error (error_code & 9) == 0. */ if (unlikely(fault_in_kernel_space(address))) { - if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) && - vmalloc_fault(address) >= 0) - return; + 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: */ if (spurious_fault(error_code, address)) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 34c1bfb64f1..f53b57e4086 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -213,7 +213,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, if (!after_bootmem) init_gbpages(); -#ifdef CONFIG_DEBUG_PAGEALLOC +#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK) /* * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages. * This will simplify cpa(), which otherwise needs to support splitting diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 949708d7a48..80cafd76a2b 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -111,7 +111,7 @@ static pte_t * __init one_page_table_init(pmd_t *pmd) pte_t *page_table = NULL; if (after_bootmem) { -#ifdef CONFIG_DEBUG_PAGEALLOC +#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK) page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE); #endif if (!page_table) |