From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Date: Thu, 27 May 2021 06:40:29 +0000 Subject: [PATCH -tip v7 09/13] kprobes: Setup instruction pointer in __kretprobe_trampoline_handler Message-Id: <162209762943.436794.874947392889792501.stgit@devnote2> List-Id: References: <162209754288.436794.3904335049560916855.stgit@devnote2> In-Reply-To: <162209754288.436794.3904335049560916855.stgit@devnote2> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Steven Rostedt , Ingo Molnar Cc: X86 ML , Masami Hiramatsu , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, Josh Poimboeuf , linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko To simplify the stacktrace with pt_regs from kretprobe handler, set the correct return address to the instruction pointer in the pt_regs before calling kretprobe handlers. Suggested-by: Josh Poimboeuf Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryik --- Changes in v3: - Cast the correct_ret_addr to unsigned long. --- kernel/kprobes.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 54e5b89aad67..1598aca375c9 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1914,6 +1914,9 @@ unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs, BUG_ON(1); } + /* Set the instruction pointer to the correct address */ + instruction_pointer_set(regs, (unsigned long)correct_ret_addr); + /* Run them. */ first = current->kretprobe_instances.first; while (first) {