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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-09-20 14:18:47 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-09-20 17:53:40 +0200 |
| commit | df297bf6c7933e7b021cdc1bf3f9e319ea3a7e9c (patch) | |
| tree | 9ef6353c4100c83176c4e7b5ef3933dc342f91df /arch/arm/mm/fault.c | |
| parent | ARM: Separate out access error checking (diff) | |
| download | linux-df297bf6c7933e7b021cdc1bf3f9e319ea3a7e9c.tar.xz linux-df297bf6c7933e7b021cdc1bf3f9e319ea3a7e9c.zip | |
ARM: Add support for checking access permissions on prefetch aborts
ARMv6 introduces non-executable mappings, which can cause prefetch aborts
when an attempt is made to execute from such a mapping. Currently, this
causes us to loop in the page fault handler since we don't correctly
check for proper permissions.
Fix this by checking that VMAs have VM_EXEC set for prefetch aborts.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/fault.c')
| -rw-r--r-- | arch/arm/mm/fault.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index b7ce07d416cd..379f78556055 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -26,8 +26,9 @@ #include "fault.h" /* - * Fault status register encodings + * Fault status register encodings. We steal bit 31 for our own purposes. */ +#define FSR_LNX_PF (1 << 31) #define FSR_WRITE (1 << 11) #define FSR_FS4 (1 << 10) #define FSR_FS3_0 (15) @@ -205,6 +206,8 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) if (fsr & FSR_WRITE) mask = VM_WRITE; + if (fsr & FSR_LNX_PF) + mask = VM_EXEC; return vma->vm_flags & mask ? false : true; } @@ -503,7 +506,7 @@ do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs) const struct fsr_info *inf = fsr_info + fsr_fs(fsr); struct siginfo info; - if (!inf->fn(addr, fsr, regs)) + if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs)) return; printk(KERN_ALERT "Unhandled fault: %s (0x%03x) at 0x%08lx\n", @@ -519,6 +522,6 @@ do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs) asmlinkage void __exception do_PrefetchAbort(unsigned long addr, struct pt_regs *regs) { - do_translation_fault(addr, 0, regs); + do_translation_fault(addr, FSR_LNX_PF, regs); } |