diff options
Diffstat (limited to 'arch/x86/mm/fault.c')
| -rw-r--r-- | arch/x86/mm/fault.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 013910b7b93f..b1104844260d 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -945,7 +945,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, vm_fault_t fault) { /* Kernel mode? Handle exceptions or die: */ - if (!(error_code & X86_PF_USER)) { + if (!user_mode(regs)) { no_context(regs, error_code, address, SIGBUS, BUS_ADRERR); return; } @@ -1217,7 +1217,14 @@ do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code, } NOKPROBE_SYMBOL(do_kern_addr_fault); -/* Handle faults in the user portion of the address space */ +/* + * Handle faults in the user portion of the address space. Nothing in here + * should check X86_PF_USER without a specific justification: for almost + * all purposes, we should treat a normal kernel access to user memory + * (e.g. get_user(), put_user(), etc.) the same as the WRUSS instruction. + * The one exception is AC flag handling, which is, per the x86 + * architecture, special for WRUSS. + */ static inline void do_user_addr_fault(struct pt_regs *regs, unsigned long error_code, @@ -1406,14 +1413,14 @@ good_area: if (likely(!(fault & VM_FAULT_ERROR))) return; - if (fatal_signal_pending(current) && !(error_code & X86_PF_USER)) { + if (fatal_signal_pending(current) && !user_mode(regs)) { no_context(regs, error_code, address, 0, 0); return; } if (fault & VM_FAULT_OOM) { /* Kernel mode? Handle exceptions or die: */ - if (!(error_code & X86_PF_USER)) { + if (!user_mode(regs)) { no_context(regs, error_code, address, SIGSEGV, SEGV_MAPERR); return; |