From 608566b4edda5079c7812c2108a89c0fcf2894bb Mon Sep 17 00:00:00 2001 From: Harvey Harrison <harvey.harrison@gmail.com> Date: Wed, 30 Jan 2008 13:33:12 +0100 Subject: [PATCH] x86: do_page_fault small unification Copy the prefetch of map_sem from X86_64 and move the check notify_page_fault (soon to be kprobe_handle_fault) out of the unlikely if() statement. This makes the X86_32|64 pagefault handlers closer to each other. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- arch/x86/mm/fault_32.c | 16 +++++++--------- arch/x86/mm/fault_64.c | 7 ++----- 2 files changed, 9 insertions(+), 14 deletions(-) diff --git a/arch/x86/mm/fault_32.c b/arch/x86/mm/fault_32.c index 36cb67e02b04..52c13d2e011e 100644 --- a/arch/x86/mm/fault_32.c +++ b/arch/x86/mm/fault_32.c @@ -295,13 +295,18 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) */ trace_hardirqs_fixup(); + tsk = current; + mm = tsk->mm; + prefetchw(&mm->mmap_sem); + /* get the address */ address = read_cr2(); - tsk = current; - si_code = SEGV_MAPERR; + if (notify_page_fault(regs)) + return; + /* * We fault-in kernel-space virtual memory on-demand. The * 'reference' page table is init_mm.pgd. @@ -319,8 +324,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) && vmalloc_fault(address) >= 0) return; - if (notify_page_fault(regs)) - return; /* * Don't take the mm semaphore here. If we fixup a prefetch * fault we could otherwise deadlock. @@ -328,16 +331,11 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) goto bad_area_nosemaphore; } - if (notify_page_fault(regs)) - return; - /* It's safe to allow irq's after cr2 has been saved and the vmalloc fault has been handled. */ if (regs->flags & (X86_EFLAGS_IF|VM_MASK)) local_irq_enable(); - mm = tsk->mm; - /* * If we're in an interrupt, have no user context or are running in an * atomic region then we must not take the fault. diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c index 80f8436ac8b2..c6b3ad515cf1 100644 --- a/arch/x86/mm/fault_64.c +++ b/arch/x86/mm/fault_64.c @@ -355,6 +355,8 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, si_code = SEGV_MAPERR; + if (notify_page_fault(regs)) + return; /* * We fault-in kernel-space virtual memory on-demand. The @@ -380,8 +382,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, if (vmalloc_fault(address) >= 0) return; } - if (notify_page_fault(regs)) - return; /* * Don't take the mm semaphore here. If we fixup a prefetch * fault we could otherwise deadlock. @@ -389,9 +389,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, goto bad_area_nosemaphore; } - if (notify_page_fault(regs)) - return; - if (likely(regs->flags & X86_EFLAGS_IF)) local_irq_enable(); -- 2.34.1