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authorCyrill Gorcunov <gorcunov@gmail.com>2012-06-07 14:21:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-06-07 14:43:55 -0700
commit736f24d5e59d699c6e300c5da7e3bb882eddda67 (patch)
tree9f703433c67763623bacb6ec1aab5a69d33903ac /kernel/sys.c
parent300f786b2683f8bb1ec0afb6e1851183a479c86d (diff)
c/r: prctl: drop VMA flags test on PR_SET_MM_ stack data assignment
In commit b76437579d13 ("procfs: mark thread stack correctly in proc/<pid>/maps") the stack allocated via clone() is marked in /proc/<pid>/maps as [stack:%d] thus it might be out of the former mm->start_stack/end_stack values (and even has some custom VMA flags set). So to be able to restore mm->start_stack/end_stack drop vma flags test, but still require the underlying VMA to exist. As always note this feature is under CONFIG_CHECKPOINT_RESTORE and requires CAP_SYS_RESOURCE to be granted. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sys.c')
-rw-r--r--kernel/sys.c14
1 files changed, 0 insertions, 14 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index 0ec1942ba7ea..f0ec44dcd415 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1786,14 +1786,6 @@ SYSCALL_DEFINE1(umask, int, mask)
}
#ifdef CONFIG_CHECKPOINT_RESTORE
-static bool vma_flags_mismatch(struct vm_area_struct *vma,
- unsigned long required,
- unsigned long banned)
-{
- return (vma->vm_flags & required) != required ||
- (vma->vm_flags & banned);
-}
-
static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
{
struct vm_area_struct *vma;
@@ -1931,12 +1923,6 @@ static int prctl_set_mm(int opt, unsigned long addr,
error = -EFAULT;
goto out;
}
-#ifdef CONFIG_STACK_GROWSUP
- if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSUP, 0))
-#else
- if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSDOWN, 0))
-#endif
- goto out;
if (opt == PR_SET_MM_START_STACK)
mm->start_stack = addr;
else if (opt == PR_SET_MM_ARG_START)