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Commit 6edaf68a authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Linus Torvalds
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[PATCH] mm: arch do_page_fault() vs in_atomic() 



In light of the recent pagefault and filemap_copy_from_user work I've gone
through all the arch pagefault handlers to make sure the inc_preempt_count()
'feature' works as expected.

Several sections of code (including the new filemap_copy_from_user) rely on
the fact that faults do not take locks under increased preempt count.

arch/x86_64 - good
arch/powerpc - good
arch/cris - fixed
arch/i386 - good
arch/parisc - fixed
arch/sh - good
arch/sparc - good
arch/s390 - good
arch/m68k - fixed
arch/ppc - good
arch/alpha - fixed
arch/mips - good
arch/sparc64 - good
arch/ia64 - good
arch/arm - fixed
arch/um - good
arch/avr32 - good
arch/h8300 - NA
arch/m32r - good
arch/v850 - good
arch/frv - fixed
arch/m68knommu - NA
arch/arm26 - fixed
arch/sh64 - fixed
arch/xtensa - good

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarNick Piggin <npiggin@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 3395ee05

arch/alpha/mm/fault.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -108,7 +108,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr, 




	/* If we're in an interrupt context, or have no user context,

	/* If we're in an interrupt context, or have no user context,

	   we must not take the fault.  */

	   we must not take the fault.  */

	if (!mm || in_interrupt())

	if (!mm || in_atomic())

		goto no_context;

		goto no_context;





#ifdef CONFIG_ALPHA_LARGE_VMALLOC

#ifdef CONFIG_ALPHA_LARGE_VMALLOC

arch/arm/mm/fault.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -230,7 +230,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) 
	 * If we're in an interrupt or have no user

	 * If we're in an interrupt or have no user

	 * context, we must not take the fault..

	 * context, we must not take the fault..

	 */

	 */

	if (in_interrupt() || !mm)

	if (in_atomic() || !mm)

		goto no_context;

		goto no_context;





	/*

	/*

arch/arm26/mm/fault.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -215,7 +215,7 @@ int do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) 
	 * If we're in an interrupt or have no user

	 * If we're in an interrupt or have no user

	 * context, we must not take the fault..

	 * context, we must not take the fault..

	 */

	 */

	if (in_interrupt() || !mm)

	if (in_atomic() || !mm)

		goto no_context;

		goto no_context;





	down_read(&mm->mmap_sem);

	down_read(&mm->mmap_sem);

arch/cris/mm/fault.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -232,7 +232,7 @@ do_page_fault(unsigned long address, struct pt_regs *regs, 
	 * context, we must not take the fault..

	 * context, we must not take the fault..

	 */

	 */





	if (in_interrupt() || !mm)

	if (in_atomic() || !mm)

		goto no_context;

		goto no_context;





	down_read(&mm->mmap_sem);

	down_read(&mm->mmap_sem);

arch/frv/mm/fault.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -78,7 +78,7 @@ asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear 
	 * If we're in an interrupt or have no user

	 * If we're in an interrupt or have no user

	 * context, we must not take the fault..

	 * context, we must not take the fault..

	 */

	 */

	if (in_interrupt() || !mm)

	if (in_atomic() || !mm)

		goto no_context;

		goto no_context;





	down_read(&mm->mmap_sem);

	down_read(&mm->mmap_sem);