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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2017-05-15 23:40:05 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-05-16 13:11:07 +1000 |
| commit | d04c02f8aa96d82e4cbe783f85a820aae820e746 (patch) | |
| tree | 01c16da24206cc7a1ec823c59a7e2197139a7bcd /arch/powerpc/kernel | |
| parent | bbb075ddf7d58762040ca413ad82e9974713def3 (diff) | |
| download | lwn-d04c02f8aa96d82e4cbe783f85a820aae820e746.tar.gz lwn-d04c02f8aa96d82e4cbe783f85a820aae820e746.zip | |
powerpc/kprobes: Fix handling of instruction emulation on probe re-entry
Commit 22d8b3dec214c ("powerpc/kprobes: Emulate instructions on kprobe
handler re-entry") enabled emulating instructions on kprobe re-entry,
rather than single-stepping always. However, we didn't update the single
stepping code to only be run if the emulation fails. Also, we missed
re-enabling preemption if the instruction emulation was successful. Fix
those issues.
Fixes: 22d8b3dec214c ("powerpc/kprobes: Emulate instructions on kprobe handler re-entry")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 160ae0fa7d0d..fc4343514bed 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -305,16 +305,17 @@ int kprobe_handler(struct pt_regs *regs) save_previous_kprobe(kcb); set_current_kprobe(p, regs, kcb); kprobes_inc_nmissed_count(p); - prepare_singlestep(p, regs); kcb->kprobe_status = KPROBE_REENTER; if (p->ainsn.boostable >= 0) { ret = try_to_emulate(p, regs); if (ret > 0) { restore_previous_kprobe(kcb); + preempt_enable_no_resched(); return 1; } } + prepare_singlestep(p, regs); return 1; } else { if (*addr != BREAKPOINT_INSTRUCTION) { |