From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yonghong Song Subject: [PATCH bpf-next v2] samples/bpf: fix kprobe attachment issue on x64 Date: Sun, 29 Apr 2018 19:27:48 -0700 Message-ID: <20180430022748.4093322-1-yhs@fb.com> Mime-Version: 1.0 Content-Type: text/plain Cc: To: , , Return-path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:34644 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750938AbeD3C1v (ORCPT ); Sun, 29 Apr 2018 22:27:51 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.22/8.16.0.22) with SMTP id w3U2Ixf8027052 for ; Sun, 29 Apr 2018 19:27:50 -0700 Received: from mail.thefacebook.com ([199.201.64.23]) by m0089730.ppops.net with ESMTP id 2hmmeyjrkk-2 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Sun, 29 Apr 2018 19:27:50 -0700 Sender: netdev-owner@vger.kernel.org List-ID: Commit d5a00528b58c ("syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()") renamed a lot of syscall function sys_*() to __x64_sys_*(). This caused several kprobe based samples/bpf tests failing. This patch fixed the problem in bpf_load.c. For x86_64 architecture, function name __x64_sys_*() will be first used for kprobe event creation. If the creation is successful, it will be used. Otherwise, function name sys_*() will be used for kprobe event creation. Fixes: d5a00528b58c ("syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()") Signed-off-by: Yonghong Song --- samples/bpf/bpf_load.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) Changelogs: v1 -> v2: . make change in bpf_load.c instead of each individual bpf programs. diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c index a27ef3c..da9bccf 100644 --- a/samples/bpf/bpf_load.c +++ b/samples/bpf/bpf_load.c @@ -145,6 +145,9 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) } if (is_kprobe || is_kretprobe) { + bool need_normal_check = true; + const char *event_prefix = ""; + if (is_kprobe) event += 7; else @@ -158,18 +161,33 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size) if (isdigit(*event)) return populate_prog_array(event, fd); - snprintf(buf, sizeof(buf), - "echo '%c:%s %s' >> /sys/kernel/debug/tracing/kprobe_events", - is_kprobe ? 'p' : 'r', event, event); - err = system(buf); - if (err < 0) { - printf("failed to create kprobe '%s' error '%s'\n", - event, strerror(errno)); - return -1; +#ifdef __x86_64__ + if (strncmp(event, "sys_", 4) == 0) { + snprintf(buf, sizeof(buf), + "echo '%c:__x64_%s __x64_%s' >> /sys/kernel/debug/tracing/kprobe_events", + is_kprobe ? 'p' : 'r', event, event); + err = system(buf); + if (err >= 0) { + need_normal_check = false; + event_prefix = "__x64_"; + } + } +#endif + if (need_normal_check) { + snprintf(buf, sizeof(buf), + "echo '%c:%s %s' >> /sys/kernel/debug/tracing/kprobe_events", + is_kprobe ? 'p' : 'r', event, event); + err = system(buf); + if (err < 0) { + printf("failed to create kprobe '%s' error '%s'\n", + event, strerror(errno)); + return -1; + } } strcpy(buf, DEBUGFS); strcat(buf, "events/kprobes/"); + strcat(buf, event_prefix); strcat(buf, event); strcat(buf, "/id"); } else if (is_tracepoint) { -- 2.9.5