* Re: [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support [not found] ` <20150203231212.223123220@linuxfoundation.org> @ 2015-02-10 8:22 ` Konstantin Khlebnikov 2015-02-11 3:43 ` Greg Kroah-Hartman 2015-02-16 9:50 ` Luis Henriques 0 siblings, 2 replies; 6+ messages in thread From: Konstantin Khlebnikov @ 2015-02-10 8:22 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Linux Kernel Mailing List, Stable, Jan Engelhardt, linux-arch, Linus Torvalds, linux-mm I've found regression: [ 257.139907] ================================================ [ 257.139909] [ BUG: lock held when returning to user space! ] [ 257.139912] 3.18.6-debug+ #161 Tainted: G U [ 257.139914] ------------------------------------------------ [ 257.139916] python/22843 is leaving the kernel with locks still held! [ 257.139918] 1 lock held by python/22843: [ 257.139920] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8104e4c2>] __do_page_fault+0x162/0x570 upstream commit 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 must be backported too. On Wed, Feb 4, 2015 at 2:13 AM, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > 3.18-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Linus Torvalds <torvalds@linux-foundation.org> > > commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream. > > The core VM already knows about VM_FAULT_SIGBUS, but cannot return a > "you should SIGSEGV" error, because the SIGSEGV case was generally > handled by the caller - usually the architecture fault handler. > > That results in lots of duplication - all the architecture fault > handlers end up doing very similar "look up vma, check permissions, do > retries etc" - but it generally works. However, there are cases where > the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV. > > In particular, when accessing the stack guard page, libsigsegv expects a > SIGSEGV. And it usually got one, because the stack growth is handled by > that duplicated architecture fault handler. > > However, when the generic VM layer started propagating the error return > from the stack expansion in commit fee7e49d4514 ("mm: propagate error > from stack expansion even for guard page"), that now exposed the > existing VM_FAULT_SIGBUS result to user space. And user space really > expected SIGSEGV, not SIGBUS. > > To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those > duplicate architecture fault handlers about it. They all already have > the code to handle SIGSEGV, so it's about just tying that new return > value to the existing code, but it's all a bit annoying. > > This is the mindless minimal patch to do this. A more extensive patch > would be to try to gather up the mostly shared fault handling logic into > one generic helper routine, and long-term we really should do that > cleanup. > > Just from this patch, you can generally see that most architectures just > copied (directly or indirectly) the old x86 way of doing things, but in > the meantime that original x86 model has been improved to hold the VM > semaphore for shorter times etc and to handle VM_FAULT_RETRY and other > "newer" things, so it would be a good idea to bring all those > improvements to the generic case and teach other architectures about > them too. > > Reported-and-tested-by: Takashi Iwai <tiwai@suse.de> > Tested-by: Jan Engelhardt <jengelh@inai.de> > Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots" > Cc: linux-arch@vger.kernel.org > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > arch/alpha/mm/fault.c | 2 ++ > arch/arc/mm/fault.c | 2 ++ > arch/avr32/mm/fault.c | 2 ++ > arch/cris/mm/fault.c | 2 ++ > arch/frv/mm/fault.c | 2 ++ > arch/ia64/mm/fault.c | 2 ++ > arch/m32r/mm/fault.c | 2 ++ > arch/m68k/mm/fault.c | 2 ++ > arch/metag/mm/fault.c | 2 ++ > arch/microblaze/mm/fault.c | 2 ++ > arch/mips/mm/fault.c | 2 ++ > arch/mn10300/mm/fault.c | 2 ++ > arch/openrisc/mm/fault.c | 2 ++ > arch/parisc/mm/fault.c | 2 ++ > arch/powerpc/mm/copro_fault.c | 2 +- > arch/powerpc/mm/fault.c | 2 ++ > arch/s390/mm/fault.c | 6 ++++++ > arch/score/mm/fault.c | 2 ++ > arch/sh/mm/fault.c | 2 ++ > arch/sparc/mm/fault_32.c | 2 ++ > arch/sparc/mm/fault_64.c | 2 ++ > arch/tile/mm/fault.c | 2 ++ > arch/um/kernel/trap.c | 2 ++ > arch/x86/mm/fault.c | 2 ++ > arch/xtensa/mm/fault.c | 2 ++ > drivers/staging/lustre/lustre/llite/vvp_io.c | 2 +- > include/linux/mm.h | 6 ++++-- > mm/gup.c | 4 ++-- > mm/ksm.c | 2 +- > 29 files changed, 61 insertions(+), 7 deletions(-) > > --- a/arch/alpha/mm/fault.c > +++ b/arch/alpha/mm/fault.c > @@ -156,6 +156,8 @@ retry: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/arc/mm/fault.c > +++ b/arch/arc/mm/fault.c > @@ -161,6 +161,8 @@ good_area: > > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > > --- a/arch/avr32/mm/fault.c > +++ b/arch/avr32/mm/fault.c > @@ -142,6 +142,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/cris/mm/fault.c > +++ b/arch/cris/mm/fault.c > @@ -176,6 +176,8 @@ retry: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/frv/mm/fault.c > +++ b/arch/frv/mm/fault.c > @@ -168,6 +168,8 @@ asmlinkage void do_page_fault(int datamm > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/ia64/mm/fault.c > +++ b/arch/ia64/mm/fault.c > @@ -172,6 +172,8 @@ retry: > */ > if (fault & VM_FAULT_OOM) { > goto out_of_memory; > + } else if (fault & VM_FAULT_SIGSEGV) { > + goto bad_area; > } else if (fault & VM_FAULT_SIGBUS) { > signal = SIGBUS; > goto bad_area; > --- a/arch/m32r/mm/fault.c > +++ b/arch/m32r/mm/fault.c > @@ -200,6 +200,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/m68k/mm/fault.c > +++ b/arch/m68k/mm/fault.c > @@ -145,6 +145,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto map_err; > else if (fault & VM_FAULT_SIGBUS) > goto bus_err; > BUG(); > --- a/arch/metag/mm/fault.c > +++ b/arch/metag/mm/fault.c > @@ -141,6 +141,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/microblaze/mm/fault.c > +++ b/arch/microblaze/mm/fault.c > @@ -224,6 +224,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/mips/mm/fault.c > +++ b/arch/mips/mm/fault.c > @@ -158,6 +158,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/mn10300/mm/fault.c > +++ b/arch/mn10300/mm/fault.c > @@ -262,6 +262,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/openrisc/mm/fault.c > +++ b/arch/openrisc/mm/fault.c > @@ -171,6 +171,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/parisc/mm/fault.c > +++ b/arch/parisc/mm/fault.c > @@ -256,6 +256,8 @@ good_area: > */ > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto bad_area; > BUG(); > --- a/arch/powerpc/mm/copro_fault.c > +++ b/arch/powerpc/mm/copro_fault.c > @@ -76,7 +76,7 @@ int copro_handle_mm_fault(struct mm_stru > if (*flt & VM_FAULT_OOM) { > ret = -ENOMEM; > goto out_unlock; > - } else if (*flt & VM_FAULT_SIGBUS) { > + } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) { > ret = -EFAULT; > goto out_unlock; > } > --- a/arch/powerpc/mm/fault.c > +++ b/arch/powerpc/mm/fault.c > @@ -444,6 +444,8 @@ good_area: > */ > fault = handle_mm_fault(mm, vma, address, flags); > if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) { > + if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > rc = mm_fault_error(regs, address, fault); > if (rc >= MM_FAULT_RETURN) > goto bail; > --- a/arch/s390/mm/fault.c > +++ b/arch/s390/mm/fault.c > @@ -374,6 +374,12 @@ static noinline void do_fault_error(stru > do_no_context(regs); > else > pagefault_out_of_memory(); > + } else if (fault & VM_FAULT_SIGSEGV) { > + /* Kernel mode? Handle exceptions or die */ > + if (!user_mode(regs)) > + do_no_context(regs); > + else > + do_sigsegv(regs, SEGV_MAPERR); > } else if (fault & VM_FAULT_SIGBUS) { > /* Kernel mode? Handle exceptions or die */ > if (!user_mode(regs)) > --- a/arch/score/mm/fault.c > +++ b/arch/score/mm/fault.c > @@ -114,6 +114,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/sh/mm/fault.c > +++ b/arch/sh/mm/fault.c > @@ -353,6 +353,8 @@ mm_fault_error(struct pt_regs *regs, uns > } else { > if (fault & VM_FAULT_SIGBUS) > do_sigbus(regs, error_code, address); > + else if (fault & VM_FAULT_SIGSEGV) > + bad_area(regs, error_code, address); > else > BUG(); > } > --- a/arch/sparc/mm/fault_32.c > +++ b/arch/sparc/mm/fault_32.c > @@ -249,6 +249,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/sparc/mm/fault_64.c > +++ b/arch/sparc/mm/fault_64.c > @@ -446,6 +446,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/tile/mm/fault.c > +++ b/arch/tile/mm/fault.c > @@ -444,6 +444,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/arch/um/kernel/trap.c > +++ b/arch/um/kernel/trap.c > @@ -80,6 +80,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) { > goto out_of_memory; > + } else if (fault & VM_FAULT_SIGSEGV) { > + goto out; > } else if (fault & VM_FAULT_SIGBUS) { > err = -EACCES; > goto out; > --- a/arch/x86/mm/fault.c > +++ b/arch/x86/mm/fault.c > @@ -905,6 +905,8 @@ mm_fault_error(struct pt_regs *regs, uns > if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON| > VM_FAULT_HWPOISON_LARGE)) > do_sigbus(regs, error_code, address, fault); > + else if (fault & VM_FAULT_SIGSEGV) > + bad_area_nosemaphore(regs, error_code, address); > else > BUG(); > } > --- a/arch/xtensa/mm/fault.c > +++ b/arch/xtensa/mm/fault.c > @@ -117,6 +117,8 @@ good_area: > if (unlikely(fault & VM_FAULT_ERROR)) { > if (fault & VM_FAULT_OOM) > goto out_of_memory; > + else if (fault & VM_FAULT_SIGSEGV) > + goto bad_area; > else if (fault & VM_FAULT_SIGBUS) > goto do_sigbus; > BUG(); > --- a/drivers/staging/lustre/lustre/llite/vvp_io.c > +++ b/drivers/staging/lustre/lustre/llite/vvp_io.c > @@ -632,7 +632,7 @@ static int vvp_io_kernel_fault(struct vv > return 0; > } > > - if (cfio->fault.ft_flags & VM_FAULT_SIGBUS) { > + if (cfio->fault.ft_flags & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) { > CDEBUG(D_PAGE, "got addr %p - SIGBUS\n", vmf->virtual_address); > return -EFAULT; > } > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1054,6 +1054,7 @@ static inline int page_mapped(struct pag > #define VM_FAULT_WRITE 0x0008 /* Special case for get_user_pages */ > #define VM_FAULT_HWPOISON 0x0010 /* Hit poisoned small page */ > #define VM_FAULT_HWPOISON_LARGE 0x0020 /* Hit poisoned large page. Index encoded in upper bits */ > +#define VM_FAULT_SIGSEGV 0x0040 > > #define VM_FAULT_NOPAGE 0x0100 /* ->fault installed the pte, not return page */ > #define VM_FAULT_LOCKED 0x0200 /* ->fault locked the returned page */ > @@ -1062,8 +1063,9 @@ static inline int page_mapped(struct pag > > #define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */ > > -#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \ > - VM_FAULT_FALLBACK | VM_FAULT_HWPOISON_LARGE) > +#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \ > + VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \ > + VM_FAULT_FALLBACK) > > /* Encode hstate index for a hwpoisoned large page */ > #define VM_FAULT_SET_HINDEX(x) ((x) << 12) > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -296,7 +296,7 @@ static int faultin_page(struct task_stru > return -ENOMEM; > if (ret & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) > return *flags & FOLL_HWPOISON ? -EHWPOISON : -EFAULT; > - if (ret & VM_FAULT_SIGBUS) > + if (ret & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) > return -EFAULT; > BUG(); > } > @@ -571,7 +571,7 @@ int fixup_user_fault(struct task_struct > return -ENOMEM; > if (ret & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) > return -EHWPOISON; > - if (ret & VM_FAULT_SIGBUS) > + if (ret & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) > return -EFAULT; > BUG(); > } > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -376,7 +376,7 @@ static int break_ksm(struct vm_area_stru > else > ret = VM_FAULT_WRITE; > put_page(page); > - } while (!(ret & (VM_FAULT_WRITE | VM_FAULT_SIGBUS | VM_FAULT_OOM))); > + } while (!(ret & (VM_FAULT_WRITE | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | VM_FAULT_OOM))); > /* > * We must loop because handle_mm_fault() may back out if there's > * any difficulty e.g. if pte accessed bit gets updated concurrently. > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support 2015-02-10 8:22 ` [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support Konstantin Khlebnikov @ 2015-02-11 3:43 ` Greg Kroah-Hartman 2015-02-11 3:49 ` Linus Torvalds 2015-02-11 5:34 ` Konstantin Khlebnikov 2015-02-16 9:50 ` Luis Henriques 1 sibling, 2 replies; 6+ messages in thread From: Greg Kroah-Hartman @ 2015-02-11 3:43 UTC (permalink / raw) To: Konstantin Khlebnikov Cc: Linux Kernel Mailing List, Stable, Jan Engelhardt, linux-arch, Linus Torvalds, linux-mm On Tue, Feb 10, 2015 at 12:22:41PM +0400, Konstantin Khlebnikov wrote: > I've found regression: > > [ 257.139907] ================================================ > [ 257.139909] [ BUG: lock held when returning to user space! ] > [ 257.139912] 3.18.6-debug+ #161 Tainted: G U > [ 257.139914] ------------------------------------------------ > [ 257.139916] python/22843 is leaving the kernel with locks still held! > [ 257.139918] 1 lock held by python/22843: > [ 257.139920] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8104e4c2>] > __do_page_fault+0x162/0x570 > > upstream commit 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 must be backported too. Ah, nice, I missed that one. How did you test this? thanks, greg k-h -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support 2015-02-11 3:43 ` Greg Kroah-Hartman @ 2015-02-11 3:49 ` Linus Torvalds 2015-02-11 4:16 ` Greg Kroah-Hartman 2015-02-11 5:34 ` Konstantin Khlebnikov 1 sibling, 1 reply; 6+ messages in thread From: Linus Torvalds @ 2015-02-11 3:49 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Konstantin Khlebnikov, Linux Kernel Mailing List, Stable, Jan Engelhardt, linux-arch, linux-mm On Tue, Feb 10, 2015 at 7:43 PM, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > > Ah, nice, I missed that one. Ugh, to be fair, I missed it too. The alternative to backporting 7fb08eca4527 is to make the backport of commit 33692f27597f use "bad_area()" instead of "bad_area_nosemaphore()". Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support 2015-02-11 3:49 ` Linus Torvalds @ 2015-02-11 4:16 ` Greg Kroah-Hartman 0 siblings, 0 replies; 6+ messages in thread From: Greg Kroah-Hartman @ 2015-02-11 4:16 UTC (permalink / raw) To: Linus Torvalds Cc: Konstantin Khlebnikov, Linux Kernel Mailing List, Stable, Jan Engelhardt, linux-arch, linux-mm On Tue, Feb 10, 2015 at 07:49:27PM -0800, Linus Torvalds wrote: > On Tue, Feb 10, 2015 at 7:43 PM, Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: > > > > Ah, nice, I missed that one. > > Ugh, to be fair, I missed it too. > > The alternative to backporting 7fb08eca4527 is to make the backport of > commit 33692f27597f use "bad_area()" instead of > "bad_area_nosemaphore()". 33692f27597f already showed up in 3.18.6, so I can't go back and change that version :( I'll just queue this one up, thanks. greg k-h -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support 2015-02-11 3:43 ` Greg Kroah-Hartman 2015-02-11 3:49 ` Linus Torvalds @ 2015-02-11 5:34 ` Konstantin Khlebnikov 1 sibling, 0 replies; 6+ messages in thread From: Konstantin Khlebnikov @ 2015-02-11 5:34 UTC (permalink / raw) To: Greg Kroah-Hartman Cc: Linux Kernel Mailing List, Stable, Jan Engelhardt, linux-arch, Linus Torvalds, linux-mm On Wed, Feb 11, 2015 at 6:43 AM, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > On Tue, Feb 10, 2015 at 12:22:41PM +0400, Konstantin Khlebnikov wrote: >> I've found regression: >> >> [ 257.139907] ================================================ >> [ 257.139909] [ BUG: lock held when returning to user space! ] >> [ 257.139912] 3.18.6-debug+ #161 Tainted: G U >> [ 257.139914] ------------------------------------------------ >> [ 257.139916] python/22843 is leaving the kernel with locks still held! >> [ 257.139918] 1 lock held by python/22843: >> [ 257.139920] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8104e4c2>] >> __do_page_fault+0x162/0x570 >> >> upstream commit 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 must be backported too. > > Ah, nice, I missed that one. How did you test this? I've catched hang on mmap_sem in some python self-test inside exherbo chroot. With that patch test has finished successfully. It seems the only way to tigger this is stack-overflow: for now VM_FAULT_SIGSEGV is returned only if kernel cannot add guard page when stack expands. > > thanks, > > greg k-h -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support 2015-02-10 8:22 ` [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support Konstantin Khlebnikov 2015-02-11 3:43 ` Greg Kroah-Hartman @ 2015-02-16 9:50 ` Luis Henriques 1 sibling, 0 replies; 6+ messages in thread From: Luis Henriques @ 2015-02-16 9:50 UTC (permalink / raw) To: Konstantin Khlebnikov Cc: Greg Kroah-Hartman, Linux Kernel Mailing List, Stable, Jan Engelhardt, linux-arch, Linus Torvalds, linux-mm On Tue, Feb 10, 2015 at 12:22:41PM +0400, Konstantin Khlebnikov wrote: > I've found regression: > > [ 257.139907] ================================================ > [ 257.139909] [ BUG: lock held when returning to user space! ] > [ 257.139912] 3.18.6-debug+ #161 Tainted: G U > [ 257.139914] ------------------------------------------------ > [ 257.139916] python/22843 is leaving the kernel with locks still held! > [ 257.139918] 1 lock held by python/22843: > [ 257.139920] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8104e4c2>] > __do_page_fault+0x162/0x570 > > upstream commit 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 must be backported too. > I guess the same regression can be found in the 3.16 kernel as it also includes a backport of 33692f27597f ("vm: add VM_FAULT_SIGSEGV handling support"). I'll queue 7fb08eca4527 ("x86: mm: move mmap_sem unlock from mm_fault_error() to caller") as well. Cheers, -- Luis > On Wed, Feb 4, 2015 at 2:13 AM, Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: > > 3.18-stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Linus Torvalds <torvalds@linux-foundation.org> > > > > commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream. > > > > The core VM already knows about VM_FAULT_SIGBUS, but cannot return a > > "you should SIGSEGV" error, because the SIGSEGV case was generally > > handled by the caller - usually the architecture fault handler. > > > > That results in lots of duplication - all the architecture fault > > handlers end up doing very similar "look up vma, check permissions, do > > retries etc" - but it generally works. However, there are cases where > > the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV. > > > > In particular, when accessing the stack guard page, libsigsegv expects a > > SIGSEGV. And it usually got one, because the stack growth is handled by > > that duplicated architecture fault handler. > > > > However, when the generic VM layer started propagating the error return > > from the stack expansion in commit fee7e49d4514 ("mm: propagate error > > from stack expansion even for guard page"), that now exposed the > > existing VM_FAULT_SIGBUS result to user space. And user space really > > expected SIGSEGV, not SIGBUS. > > > > To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those > > duplicate architecture fault handlers about it. They all already have > > the code to handle SIGSEGV, so it's about just tying that new return > > value to the existing code, but it's all a bit annoying. > > > > This is the mindless minimal patch to do this. A more extensive patch > > would be to try to gather up the mostly shared fault handling logic into > > one generic helper routine, and long-term we really should do that > > cleanup. > > > > Just from this patch, you can generally see that most architectures just > > copied (directly or indirectly) the old x86 way of doing things, but in > > the meantime that original x86 model has been improved to hold the VM > > semaphore for shorter times etc and to handle VM_FAULT_RETRY and other > > "newer" things, so it would be a good idea to bring all those > > improvements to the generic case and teach other architectures about > > them too. > > > > Reported-and-tested-by: Takashi Iwai <tiwai@suse.de> > > Tested-by: Jan Engelhardt <jengelh@inai.de> > > Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots" > > Cc: linux-arch@vger.kernel.org > > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > > > --- > > arch/alpha/mm/fault.c | 2 ++ > > arch/arc/mm/fault.c | 2 ++ > > arch/avr32/mm/fault.c | 2 ++ > > arch/cris/mm/fault.c | 2 ++ > > arch/frv/mm/fault.c | 2 ++ > > arch/ia64/mm/fault.c | 2 ++ > > arch/m32r/mm/fault.c | 2 ++ > > arch/m68k/mm/fault.c | 2 ++ > > arch/metag/mm/fault.c | 2 ++ > > arch/microblaze/mm/fault.c | 2 ++ > > arch/mips/mm/fault.c | 2 ++ > > arch/mn10300/mm/fault.c | 2 ++ > > arch/openrisc/mm/fault.c | 2 ++ > > arch/parisc/mm/fault.c | 2 ++ > > arch/powerpc/mm/copro_fault.c | 2 +- > > arch/powerpc/mm/fault.c | 2 ++ > > arch/s390/mm/fault.c | 6 ++++++ > > arch/score/mm/fault.c | 2 ++ > > arch/sh/mm/fault.c | 2 ++ > > arch/sparc/mm/fault_32.c | 2 ++ > > arch/sparc/mm/fault_64.c | 2 ++ > > arch/tile/mm/fault.c | 2 ++ > > arch/um/kernel/trap.c | 2 ++ > > arch/x86/mm/fault.c | 2 ++ > > arch/xtensa/mm/fault.c | 2 ++ > > drivers/staging/lustre/lustre/llite/vvp_io.c | 2 +- > > include/linux/mm.h | 6 ++++-- > > mm/gup.c | 4 ++-- > > mm/ksm.c | 2 +- > > 29 files changed, 61 insertions(+), 7 deletions(-) > > > > --- a/arch/alpha/mm/fault.c > > +++ b/arch/alpha/mm/fault.c > > @@ -156,6 +156,8 @@ retry: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/arc/mm/fault.c > > +++ b/arch/arc/mm/fault.c > > @@ -161,6 +161,8 @@ good_area: > > > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > > > --- a/arch/avr32/mm/fault.c > > +++ b/arch/avr32/mm/fault.c > > @@ -142,6 +142,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/cris/mm/fault.c > > +++ b/arch/cris/mm/fault.c > > @@ -176,6 +176,8 @@ retry: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/frv/mm/fault.c > > +++ b/arch/frv/mm/fault.c > > @@ -168,6 +168,8 @@ asmlinkage void do_page_fault(int datamm > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/ia64/mm/fault.c > > +++ b/arch/ia64/mm/fault.c > > @@ -172,6 +172,8 @@ retry: > > */ > > if (fault & VM_FAULT_OOM) { > > goto out_of_memory; > > + } else if (fault & VM_FAULT_SIGSEGV) { > > + goto bad_area; > > } else if (fault & VM_FAULT_SIGBUS) { > > signal = SIGBUS; > > goto bad_area; > > --- a/arch/m32r/mm/fault.c > > +++ b/arch/m32r/mm/fault.c > > @@ -200,6 +200,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/m68k/mm/fault.c > > +++ b/arch/m68k/mm/fault.c > > @@ -145,6 +145,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto map_err; > > else if (fault & VM_FAULT_SIGBUS) > > goto bus_err; > > BUG(); > > --- a/arch/metag/mm/fault.c > > +++ b/arch/metag/mm/fault.c > > @@ -141,6 +141,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/microblaze/mm/fault.c > > +++ b/arch/microblaze/mm/fault.c > > @@ -224,6 +224,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/mips/mm/fault.c > > +++ b/arch/mips/mm/fault.c > > @@ -158,6 +158,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/mn10300/mm/fault.c > > +++ b/arch/mn10300/mm/fault.c > > @@ -262,6 +262,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/openrisc/mm/fault.c > > +++ b/arch/openrisc/mm/fault.c > > @@ -171,6 +171,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/parisc/mm/fault.c > > +++ b/arch/parisc/mm/fault.c > > @@ -256,6 +256,8 @@ good_area: > > */ > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto bad_area; > > BUG(); > > --- a/arch/powerpc/mm/copro_fault.c > > +++ b/arch/powerpc/mm/copro_fault.c > > @@ -76,7 +76,7 @@ int copro_handle_mm_fault(struct mm_stru > > if (*flt & VM_FAULT_OOM) { > > ret = -ENOMEM; > > goto out_unlock; > > - } else if (*flt & VM_FAULT_SIGBUS) { > > + } else if (*flt & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) { > > ret = -EFAULT; > > goto out_unlock; > > } > > --- a/arch/powerpc/mm/fault.c > > +++ b/arch/powerpc/mm/fault.c > > @@ -444,6 +444,8 @@ good_area: > > */ > > fault = handle_mm_fault(mm, vma, address, flags); > > if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) { > > + if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > rc = mm_fault_error(regs, address, fault); > > if (rc >= MM_FAULT_RETURN) > > goto bail; > > --- a/arch/s390/mm/fault.c > > +++ b/arch/s390/mm/fault.c > > @@ -374,6 +374,12 @@ static noinline void do_fault_error(stru > > do_no_context(regs); > > else > > pagefault_out_of_memory(); > > + } else if (fault & VM_FAULT_SIGSEGV) { > > + /* Kernel mode? Handle exceptions or die */ > > + if (!user_mode(regs)) > > + do_no_context(regs); > > + else > > + do_sigsegv(regs, SEGV_MAPERR); > > } else if (fault & VM_FAULT_SIGBUS) { > > /* Kernel mode? Handle exceptions or die */ > > if (!user_mode(regs)) > > --- a/arch/score/mm/fault.c > > +++ b/arch/score/mm/fault.c > > @@ -114,6 +114,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/sh/mm/fault.c > > +++ b/arch/sh/mm/fault.c > > @@ -353,6 +353,8 @@ mm_fault_error(struct pt_regs *regs, uns > > } else { > > if (fault & VM_FAULT_SIGBUS) > > do_sigbus(regs, error_code, address); > > + else if (fault & VM_FAULT_SIGSEGV) > > + bad_area(regs, error_code, address); > > else > > BUG(); > > } > > --- a/arch/sparc/mm/fault_32.c > > +++ b/arch/sparc/mm/fault_32.c > > @@ -249,6 +249,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/sparc/mm/fault_64.c > > +++ b/arch/sparc/mm/fault_64.c > > @@ -446,6 +446,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/tile/mm/fault.c > > +++ b/arch/tile/mm/fault.c > > @@ -444,6 +444,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/arch/um/kernel/trap.c > > +++ b/arch/um/kernel/trap.c > > @@ -80,6 +80,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) { > > goto out_of_memory; > > + } else if (fault & VM_FAULT_SIGSEGV) { > > + goto out; > > } else if (fault & VM_FAULT_SIGBUS) { > > err = -EACCES; > > goto out; > > --- a/arch/x86/mm/fault.c > > +++ b/arch/x86/mm/fault.c > > @@ -905,6 +905,8 @@ mm_fault_error(struct pt_regs *regs, uns > > if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON| > > VM_FAULT_HWPOISON_LARGE)) > > do_sigbus(regs, error_code, address, fault); > > + else if (fault & VM_FAULT_SIGSEGV) > > + bad_area_nosemaphore(regs, error_code, address); > > else > > BUG(); > > } > > --- a/arch/xtensa/mm/fault.c > > +++ b/arch/xtensa/mm/fault.c > > @@ -117,6 +117,8 @@ good_area: > > if (unlikely(fault & VM_FAULT_ERROR)) { > > if (fault & VM_FAULT_OOM) > > goto out_of_memory; > > + else if (fault & VM_FAULT_SIGSEGV) > > + goto bad_area; > > else if (fault & VM_FAULT_SIGBUS) > > goto do_sigbus; > > BUG(); > > --- a/drivers/staging/lustre/lustre/llite/vvp_io.c > > +++ b/drivers/staging/lustre/lustre/llite/vvp_io.c > > @@ -632,7 +632,7 @@ static int vvp_io_kernel_fault(struct vv > > return 0; > > } > > > > - if (cfio->fault.ft_flags & VM_FAULT_SIGBUS) { > > + if (cfio->fault.ft_flags & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) { > > CDEBUG(D_PAGE, "got addr %p - SIGBUS\n", vmf->virtual_address); > > return -EFAULT; > > } > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -1054,6 +1054,7 @@ static inline int page_mapped(struct pag > > #define VM_FAULT_WRITE 0x0008 /* Special case for get_user_pages */ > > #define VM_FAULT_HWPOISON 0x0010 /* Hit poisoned small page */ > > #define VM_FAULT_HWPOISON_LARGE 0x0020 /* Hit poisoned large page. Index encoded in upper bits */ > > +#define VM_FAULT_SIGSEGV 0x0040 > > > > #define VM_FAULT_NOPAGE 0x0100 /* ->fault installed the pte, not return page */ > > #define VM_FAULT_LOCKED 0x0200 /* ->fault locked the returned page */ > > @@ -1062,8 +1063,9 @@ static inline int page_mapped(struct pag > > > > #define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */ > > > > -#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | \ > > - VM_FAULT_FALLBACK | VM_FAULT_HWPOISON_LARGE) > > +#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \ > > + VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \ > > + VM_FAULT_FALLBACK) > > > > /* Encode hstate index for a hwpoisoned large page */ > > #define VM_FAULT_SET_HINDEX(x) ((x) << 12) > > --- a/mm/gup.c > > +++ b/mm/gup.c > > @@ -296,7 +296,7 @@ static int faultin_page(struct task_stru > > return -ENOMEM; > > if (ret & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) > > return *flags & FOLL_HWPOISON ? -EHWPOISON : -EFAULT; > > - if (ret & VM_FAULT_SIGBUS) > > + if (ret & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) > > return -EFAULT; > > BUG(); > > } > > @@ -571,7 +571,7 @@ int fixup_user_fault(struct task_struct > > return -ENOMEM; > > if (ret & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) > > return -EHWPOISON; > > - if (ret & VM_FAULT_SIGBUS) > > + if (ret & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV)) > > return -EFAULT; > > BUG(); > > } > > --- a/mm/ksm.c > > +++ b/mm/ksm.c > > @@ -376,7 +376,7 @@ static int break_ksm(struct vm_area_stru > > else > > ret = VM_FAULT_WRITE; > > put_page(page); > > - } while (!(ret & (VM_FAULT_WRITE | VM_FAULT_SIGBUS | VM_FAULT_OOM))); > > + } while (!(ret & (VM_FAULT_WRITE | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | VM_FAULT_OOM))); > > /* > > * We must loop because handle_mm_fault() may back out if there's > > * any difficulty e.g. if pte accessed bit gets updated concurrently. > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-02-16 9:49 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <20150203231211.486950145@linuxfoundation.org>
[not found] ` <20150203231212.223123220@linuxfoundation.org>
2015-02-10 8:22 ` [PATCH 3.18 04/57] vm: add VM_FAULT_SIGSEGV handling support Konstantin Khlebnikov
2015-02-11 3:43 ` Greg Kroah-Hartman
2015-02-11 3:49 ` Linus Torvalds
2015-02-11 4:16 ` Greg Kroah-Hartman
2015-02-11 5:34 ` Konstantin Khlebnikov
2015-02-16 9:50 ` Luis Henriques
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox