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x86/kprobes: Fix __recover_optprobed_insn check optimizing logic 

Since the following commit:

  commit f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")

modified the update timing of the KPROBE_FLAG_OPTIMIZED, a optimized_kprobe
may be in the optimizing or unoptimizing state when op.kp->flags
has KPROBE_FLAG_OPTIMIZED and op->list is not empty.

The __recover_optprobed_insn check logic is incorrect, a kprobe in the
unoptimizing state may be incorrectly determined as unoptimizing.
As a result, incorrect instructions are copied.

The optprobe_queued_unopt function needs to be exported for invoking in
arch directory.

Link: https://lore.kernel.org/all/20230216034247.32348-2-yangjihong1@huawei.com/

Fixes: f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")
Cc: stable@vger.kernel.org
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This commit is contained in:
Yang Jihong 2023-02-21 08:49:16 +09:00 committed by Masami Hiramatsu (Google)
parent 4fbd2f83fd
commit 868a6fc0ca
3 changed files with 4 additions and 3 deletions
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4
arch/x86/kernel/kprobes/opt.c
View File

@ -46,8 +46,8 @@ unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr)
/* This function only handles jump-optimized kprobe */
if (kp && kprobe_optimized(kp)) {
op = container_of(kp, struct optimized_kprobe, kp);
/* If op->list is not empty, op is under optimizing */
if (list_empty(&op->list))
/* If op is optimized or under unoptimizing */
if (list_empty(&op->list) || optprobe_queued_unopt(op))
goto found;
}
}

1
include/linux/kprobes.h
View File

@ -378,6 +378,7 @@ extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
DEFINE_INSN_CACHE_OPS(optinsn);
extern void wait_for_kprobe_optimizer(void);
bool optprobe_queued_unopt(struct optimized_kprobe *op);
#else /* !CONFIG_OPTPROBES */
static inline void wait_for_kprobe_optimizer(void) { }
#endif /* CONFIG_OPTPROBES */

2
kernel/kprobes.c
View File

@ -660,7 +660,7 @@ void wait_for_kprobe_optimizer(void)
mutex_unlock(&kprobe_mutex);
}
static bool optprobe_queued_unopt(struct optimized_kprobe *op)
bool optprobe_queued_unopt(struct optimized_kprobe *op)
{
struct optimized_kprobe *_op;