From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] powerpc/kprobes: Remove redundant code
Date: Fri, 14 Feb 2020 13:44:15 +0000 (UTC) [thread overview]
Message-ID: <642c8b4ca59e658be38d8dde00f994e183790a6a.1581687838.git.christophe.leroy@c-s.fr> (raw)
At the time being we have something like
if (something) {
p = get();
if (p) {
if (something_wrong)
goto out;
...
return;
} else if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
p = get();
if (!p) {
if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
This is similar to
p = get();
if (something) {
if (p) {
if (something_wrong)
goto out;
...
return;
}
}
if (!p) {
if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/kernel/kprobes.c | 15 +--------------
1 file changed, 1 insertion(+), 14 deletions(-)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index f8b848aa65bd..7a925eb76ec0 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -276,8 +276,8 @@ int kprobe_handler(struct pt_regs *regs)
kcb = get_kprobe_ctlblk();
/* Check we're not actually recursing */
+ p = get_kprobe(addr);
if (kprobe_running()) {
- p = get_kprobe(addr);
if (p) {
kprobe_opcode_t insn = *p->ainsn.insn;
if (kcb->kprobe_status == KPROBE_HIT_SS &&
@@ -308,22 +308,9 @@ int kprobe_handler(struct pt_regs *regs)
}
prepare_singlestep(p, regs);
return 1;
- } else if (*addr != BREAKPOINT_INSTRUCTION) {
- /* If trap variant, then it belongs not to us */
- kprobe_opcode_t cur_insn = *addr;
-
- if (is_trap(cur_insn))
- goto no_kprobe;
- /* The breakpoint instruction was removed by
- * another cpu right after we hit, no further
- * handling of this interrupt is appropriate
- */
- ret = 1;
}
- goto no_kprobe;
}
- p = get_kprobe(addr);
if (!p) {
if (*addr != BREAKPOINT_INSTRUCTION) {
/*
--
2.25.0
next reply other threads:[~2020-02-14 13:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-14 13:44 Christophe Leroy [this message]
2020-02-14 13:44 ` [PATCH 2/2] powerpc/kprobes: Reduce depth of a test Christophe Leroy
2020-02-18 14:40 ` Naveen N. Rao
2020-02-18 14:39 ` [PATCH 1/2] powerpc/kprobes: Remove redundant code Naveen N. Rao
2020-02-19 7:48 ` Christophe Leroy
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