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| author | Oleg Nesterov <oleg@redhat.com> | 2012-09-30 20:31:41 +0200 |
|---|---|---|
| committer | Anton Arapov <anton@redhat.com> | 2012-10-29 11:50:19 +0100 |
| commit | 7e0dbbe849e1d99b1b3ae1b5acc7a1dabaf64e7f (patch) | |
| tree | 7984c88cbbdc57b2b69b9f0a8bae7efc6309e110 /arch/mn10300/oprofile | |
| parent | 50dfafcb45e17878104d94f7a479de83ec76d6b6 (diff) | |
| download | kernel-uprobes-7e0dbbe849e1d99b1b3ae1b5acc7a1dabaf64e7f.tar.gz kernel-uprobes-7e0dbbe849e1d99b1b3ae1b5acc7a1dabaf64e7f.tar.xz kernel-uprobes-7e0dbbe849e1d99b1b3ae1b5acc7a1dabaf64e7f.zip | |
uprobes: Fix prepare_uprobe() race with itself
install_breakpoint() is called under mm->mmap_sem, this protects
set_swbp() but not prepare_uprobe(). Two or more different tasks
can call install_breakpoint()->prepare_uprobe() at the same time,
this leads to numerous problems if UPROBE_COPY_INSN is not set.
Just for example, the second copy_insn() can corrupt the already
analyzed/fixuped uprobe->arch.insn and race with handle_swbp().
This patch simply adds uprobe->copy_mutex to serialize this code.
We could probably reuse ->consumer_rwsem, but this would mean that
consumer->handler() can not use mm->mmap_sem, not good.
Note: this is another temporary ugly hack until we move this logic
into uprobe_register().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Diffstat (limited to 'arch/mn10300/oprofile')
0 files changed, 0 insertions, 0 deletions