From: Peter Zijlstra 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: Peter Zijlstra Acked-by: Nick Piggin Signed-off-by: Andrew Morton --- arch/alpha/mm/fault.c | 2 +- arch/arm/mm/fault.c | 2 +- arch/arm26/mm/fault.c | 2 +- arch/cris/mm/fault.c | 2 +- arch/frv/mm/fault.c | 2 +- arch/m68k/mm/fault.c | 2 +- arch/parisc/mm/fault.c | 2 +- arch/sh64/mm/fault.c | 2 +- 8 files changed, 8 insertions(+), 8 deletions(-) diff -puN arch/alpha/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic arch/alpha/mm/fault.c --- a/arch/alpha/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic +++ a/arch/alpha/mm/fault.c @@ -108,7 +108,7 @@ do_page_fault(unsigned long address, uns /* If we're in an interrupt context, or have no user context, we must not take the fault. */ - if (!mm || in_interrupt()) + if (!mm || in_atomic()) goto no_context; #ifdef CONFIG_ALPHA_LARGE_VMALLOC diff -puN arch/arm/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic arch/arm/mm/fault.c --- a/arch/arm/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic +++ a/arch/arm/mm/fault.c @@ -230,7 +230,7 @@ do_page_fault(unsigned long addr, unsign * If we're in an interrupt or have no user * context, we must not take the fault.. */ - if (in_interrupt() || !mm) + if (in_atomic() || !mm) goto no_context; /* diff -puN arch/arm26/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic arch/arm26/mm/fault.c --- a/arch/arm26/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic +++ a/arch/arm26/mm/fault.c @@ -215,7 +215,7 @@ int do_page_fault(unsigned long addr, un * If we're in an interrupt or have no user * context, we must not take the fault.. */ - if (in_interrupt() || !mm) + if (in_atomic() || !mm) goto no_context; down_read(&mm->mmap_sem); diff -puN arch/cris/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic arch/cris/mm/fault.c --- a/arch/cris/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic +++ a/arch/cris/mm/fault.c @@ -232,7 +232,7 @@ do_page_fault(unsigned long address, str * context, we must not take the fault.. */ - if (in_interrupt() || !mm) + if (in_atomic() || !mm) goto no_context; down_read(&mm->mmap_sem); diff -puN arch/frv/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic arch/frv/mm/fault.c --- a/arch/frv/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic +++ a/arch/frv/mm/fault.c @@ -78,7 +78,7 @@ asmlinkage void do_page_fault(int datamm * If we're in an interrupt or have no user * context, we must not take the fault.. */ - if (in_interrupt() || !mm) + if (in_atomic() || !mm) goto no_context; down_read(&mm->mmap_sem); diff -puN arch/m68k/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic arch/m68k/mm/fault.c --- a/arch/m68k/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic +++ a/arch/m68k/mm/fault.c @@ -99,7 +99,7 @@ int do_page_fault(struct pt_regs *regs, * If we're in an interrupt or have no user * context, we must not take the fault.. */ - if (in_interrupt() || !mm) + if (in_atomic() || !mm) goto no_context; down_read(&mm->mmap_sem); diff -puN arch/parisc/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic arch/parisc/mm/fault.c --- a/arch/parisc/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic +++ a/arch/parisc/mm/fault.c @@ -152,7 +152,7 @@ void do_page_fault(struct pt_regs *regs, const struct exception_table_entry *fix; unsigned long acc_type; - if (in_interrupt() || !mm) + if (in_atomic() || !mm) goto no_context; down_read(&mm->mmap_sem); diff -puN arch/sh64/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic arch/sh64/mm/fault.c --- a/arch/sh64/mm/fault.c~mm-arch-do_page_fault-vs-in_atomic +++ a/arch/sh64/mm/fault.c @@ -154,7 +154,7 @@ asmlinkage void do_page_fault(struct pt_ * If we're in an interrupt or have no user * context, we must not take the fault.. */ - if (in_interrupt() || !mm) + if (in_atomic() || !mm) goto no_context; /* TLB misses upon some cache flushes get done under cli() */ _