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 <mhocko@suse.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>	[x86 vdso]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index a647d66..4a803c5 100644 (file)
--- 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 (file)
--- 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..3ea9684 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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|