From 190b1a7c7f5328355b967d89486bbda972f22562 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 19 Jul 2017 14:49:41 +1000 Subject: [PATCH] powerpc/mm: Add a bunch of (un)likely annotations to do_page_fault Mostly for the failure cases Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman --- arch/powerpc/mm/fault.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 7928445593432..572c801295817 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -400,7 +400,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, * source. If this is invalid we can skip the address space check, * thus avoiding the deadlock. */ - if (!down_read_trylock(&mm->mmap_sem)) { + if (unlikely(!down_read_trylock(&mm->mmap_sem))) { if (!is_user && !search_exception_tables(regs->nip)) return bad_area_nosemaphore(regs, address); @@ -416,11 +416,11 @@ retry: } vma = find_vma(mm, address); - if (!vma) + if (unlikely(!vma)) return bad_area(regs, address); - if (vma->vm_start <= address) + if (likely(vma->vm_start <= address)) goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) + if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) return bad_area(regs, address); /* @@ -453,7 +453,7 @@ retry: if (address + 2048 < uregs->gpr[1] && !store_update_sp) return bad_area(regs, address); } - if (expand_stack(vma, address)) + if (unlikely(expand_stack(vma, address))) return bad_area(regs, address); good_area: @@ -468,18 +468,18 @@ good_area: * below wouldn't be valid on those processors. This -may- * break programs compiled with a really old ABI though. */ - if (!(vma->vm_flags & VM_EXEC) && - (cpu_has_feature(CPU_FTR_NOEXECUTE) || - !(vma->vm_flags & (VM_READ | VM_WRITE)))) + if (unlikely(!(vma->vm_flags & VM_EXEC) && + (cpu_has_feature(CPU_FTR_NOEXECUTE) || + !(vma->vm_flags & (VM_READ | VM_WRITE))))) return bad_area(regs, address); /* a write */ } else if (is_write) { - if (!(vma->vm_flags & VM_WRITE)) + if (unlikely(!(vma->vm_flags & VM_WRITE))) return bad_area(regs, address); flags |= FAULT_FLAG_WRITE; /* a read */ } else { - if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) + if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))) return bad_area(regs, address); } -- 2.39.5