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| author | Cyrill Gorcunov <gorcunov@gmail.com> | 2012-06-07 14:21:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-07 14:43:55 -0700 |
| commit | 736f24d5e59d699c6e300c5da7e3bb882eddda67 (patch) | |
| tree | 9f703433c67763623bacb6ec1aab5a69d33903ac /kernel/sys.c | |
| parent | 300f786b2683f8bb1ec0afb6e1851183a479c86d (diff) | |
| download | linux-736f24d5e59d699c6e300c5da7e3bb882eddda67.tar.gz linux-736f24d5e59d699c6e300c5da7e3bb882eddda67.tar.bz2 linux-736f24d5e59d699c6e300c5da7e3bb882eddda67.zip | |
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.c | 14 |
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) |