diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2016-02-27 23:11:28 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-29 08:47:51 +0100 |
| commit | 869ae76147ffdf21ad24f0e599303cd58a2bb39f (patch) | |
| tree | b05b3db6be6d5eff0ba0ce179bfabaa2ec108463 /kernel/events/uprobes.c | |
| parent | 0f68c088c0adb3c3bbeb487c4ebcde91fd5d34be (diff) | |
uprobes: __create_xol_area() must nullify xol_mapping.fault
As Jiri pointed out, this recent commit:
f872f5400cc0 ("mm: Add a vm_special_mapping.fault() method")
breaks uprobes: __create_xol_area() doesn't initialize the new ->fault()
method and this obviously leads to kernel crash when the application
tries to execute the probed insn after bp hit.
We probably want to add uprobes_special_mapping_fault(), this allows to
turn xol_area->xol_mapping into a single instance of vm_special_mapping.
But we need a simple fix, so lets change __create_xol() to nullify the
new member as Jiri suggests.
Suggested-by: Jiri Olsa <jolsa@redhat.com>
Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <tipbot@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160227221128.GA29565@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events/uprobes.c')
| -rw-r--r-- | kernel/events/uprobes.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 0167679182c0..5f6ce931f1ea 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1178,6 +1178,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr) goto free_area; area->xol_mapping.name = "[uprobes]"; + area->xol_mapping.fault = NULL; area->xol_mapping.pages = area->pages; area->pages[0] = alloc_page(GFP_HIGHUSER); if (!area->pages[0]) |