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authorNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>2017-05-15 20:10:05 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2017-05-16 05:11:07 +0200
commitd04c02f8aa96d82e4cbe783f85a820aae820e746 (patch)
tree01c16da24206cc7a1ec823c59a7e2197139a7bcd /arch/powerpc
parentpowerpc/powernv: Set NAPSTATELOST after recovering paca on P9 DD1 (diff)
downloadlinux-d04c02f8aa96d82e4cbe783f85a820aae820e746.tar.xz
linux-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')
-rw-r--r--arch/powerpc/kernel/kprobes.c3
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) {