From 69048176078adda4087a648c9b1812ddd800fad1 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Mon, 23 May 2016 16:25:54 -0700 Subject: vdso: make arch_setup_additional_pages wait for mmap_sem for write killable most architectures are relying on mmap_sem for write in their arch_setup_additional_pages. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by: Michal Hocko Acked-by: Andy Lutomirski [x86 vdso] Acked-by: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index a647d66..4a803c5 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -420,7 +420,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) npages = 1; /* for sigpage */ npages += vdso_total_pages; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; hint = sigpage_addr(mm, npages); addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0); if (IS_ERR_VALUE(addr)) { diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 64fc030..9fefb00 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -95,7 +95,8 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp) }; void *ret; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; current->mm->context.vdso = (void *)addr; /* Map vectors page at the high address. */ @@ -163,7 +164,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, /* Be sure to map the data page */ vdso_mapping_len = vdso_text_len + PAGE_SIZE; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); if (IS_ERR_VALUE(vdso_base)) { ret = ERR_PTR(vdso_base); diff --git a/arch/hexagon/kernel/vdso.c b/arch/hexagon/kernel/vdso.c index 0bf5a87..3ea96841 100644 --- a/arch/hexagon/kernel/vdso.c +++ b/arch/hexagon/kernel/vdso.c @@ -65,7 +65,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) unsigned long vdso_base; struct mm_struct *mm = current->mm; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; /* Try to get it loaded right near ld.so/glibc. */ vdso_base = STACK_TOP; diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c index 975e997..54e1663 100644 --- a/arch/mips/kernel/vdso.c +++ b/arch/mips/kernel/vdso.c @@ -104,7 +104,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) struct resource gic_res; int ret; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; /* * Determine total area size. This includes the VDSO data itself, the diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index def1b8b..6767605 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -195,7 +195,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) * and end up putting it elsewhere. * Add enough to the size so that the result can be aligned. */ - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; vdso_base = get_unmapped_area(NULL, vdso_base, (vdso_pages << PAGE_SHIFT) + ((VDSO_ALIGNMENT - 1) & PAGE_MASK), diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index 94495ca..5904abf 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -216,7 +216,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) * it at vdso_base which is the "natural" base for it, but we might * fail and end up putting it elsewhere. */ - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; vdso_base = get_unmapped_area(NULL, 0, vdso_pages << PAGE_SHIFT, 0, 0); if (IS_ERR_VALUE(vdso_base)) { rc = vdso_base; diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c index ea2aa13..cc0cc5b 100644 --- a/arch/sh/kernel/vsyscall/vsyscall.c +++ b/arch/sh/kernel/vsyscall/vsyscall.c @@ -64,7 +64,9 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) unsigned long addr; int ret; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; + addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); if (IS_ERR_VALUE(addr)) { ret = addr; diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index b3cf813..ab220ac 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -163,7 +163,8 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr) addr = 0; } - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; addr = get_unmapped_area(NULL, addr, image->size - image->sym_vvar_start, 0, 0); diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c index 237c683..6be22f9 100644 --- a/arch/x86/um/vdso/vma.c +++ b/arch/x86/um/vdso/vma.c @@ -61,7 +61,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) if (!vdso_enabled) return 0; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE, VM_READ|VM_EXEC| -- cgit v0.10.2