linux/kernel/events
Oleg Nesterov f8ac4ec9c0 uprobes: Introduce MMF_HAS_UPROBES
Add the new MMF_HAS_UPROBES flag. It is set by install_breakpoint()
and it is copied by dup_mmap(), uprobe_pre_sstep_notifier() checks
it to avoid the slow path if the task was never probed. Perhaps it
makes sense to check it in valid_vma(is_register => false) as well.

This needs the new dup_mmap()->uprobe_dup_mmap() hook. We can't use
uprobe_reset_state() or put MMF_HAS_UPROBES into MMF_INIT_MASK, we
need oldmm->mmap_sem to avoid the race with uprobe_register() or
mmap() from another thread.

Currently we never clear this bit, it can be false-positive after
uprobe_unregister() or uprobe_munmap() or if dup_mmap() hits the
probed VM_DONTCOPY vma. But this is fine correctness-wise and has
no effect unless the task hits the non-uprobe breakpoint.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
2012-08-28 18:21:18 +02:00
..
callchain.c perf: Add attribute to filter out callchains 2012-08-10 12:40:57 -03:00
core.c perf: Add ability to attach user stack dump to sample 2012-08-10 12:17:58 -03:00
hw_breakpoint.c Merge branch 'x86/cleanups' into perf/uprobes 2012-03-13 16:33:03 +01:00
internal.h perf: Add ability to attach user stack dump to sample 2012-08-10 12:17:58 -03:00
Makefile uprobes: Move to kernel/events/ 2012-02-22 11:08:00 +01:00
ring_buffer.c perf: Add perf_output_skip function to skip bytes in sample 2012-08-10 12:16:22 -03:00
uprobes.c uprobes: Introduce MMF_HAS_UPROBES 2012-08-28 18:21:18 +02:00