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Commit b15021d9 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Michael Ellerman
Browse files

powerpc/mm: Add a bunch of (un)likely annotations to do_page_fault 



Mostly for the failure cases

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 11ccdd33

arch/powerpc/mm/fault.c

+10 −10
Original line number Diff line number Diff line
@@ -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 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, 
	}



	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 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, 
		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 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, 
		 * 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) &&

		if (unlikely(!(vma->vm_flags & VM_EXEC) &&

			     (cpu_has_feature(CPU_FTR_NOEXECUTE) ||

		     !(vma->vm_flags & (VM_READ | VM_WRITE))))

			      !(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);

	}