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author | Cyrill Gorcunov <gorcunov@openvz.org> | 2012-05-31 16:26:46 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-31 17:49:32 -0700 |
commit | b32dfe377102ce668775f8b6b1461f7ad428f8b6 (patch) | |
tree | f89be6bd34eb757c471f3ca506e0ce92224f9bc5 /init | |
parent | fe8c7f5cbf91124987106faa3bdf0c8b955c4cf7 (diff) | |
download | op-kernel-dev-b32dfe377102ce668775f8b6b1461f7ad428f8b6.zip op-kernel-dev-b32dfe377102ce668775f8b6b1461f7ad428f8b6.tar.gz |
c/r: prctl: add ability to set new mm_struct::exe_file
When we do restore we would like to have a way to setup a former
mm_struct::exe_file so that /proc/pid/exe would point to the original
executable file a process had at checkpoint time.
For this the PR_SET_MM_EXE_FILE code is introduced. This option takes a
file descriptor which will be set as a source for new /proc/$pid/exe
symlink.
Note it allows to change /proc/$pid/exe if there are no VM_EXECUTABLE
vmas present for current process, simply because this feature is a special
to C/R and mm::num_exe_file_vmas become meaningless after that.
To minimize the amount of transition the /proc/pid/exe symlink might have,
this feature is implemented in one-shot manner. Thus once changed the
symlink can't be changed again. This should help sysadmins to monitor the
symlinks over all process running in a system.
In particular one could make a snapshot of processes and ring alarm if
there unexpected changes of /proc/pid/exe's in a system.
Note -- this feature is available iif CONFIG_CHECKPOINT_RESTORE is set and
the caller must have CAP_SYS_RESOURCE capability granted, otherwise the
request to change symlink will be rejected.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions