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authorYonghong Song <yhs@fb.com>2018-04-29 19:27:48 -0700
committerAlexei Starovoitov <ast@kernel.org>2018-04-29 20:36:53 -0700
commit34745aed515c1d6040110ff82378056533518eb6 (patch)
treebdd6bbae3a8616d5a53f4299932aceecf61f5921
parent7ef3771205302a71a8bb4a2286ef98e5cade5d1a (diff)
samples/bpf: fix kprobe attachment issue on x64
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 <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r--samples/bpf/bpf_load.c34
1 files changed, 26 insertions, 8 deletions
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index a27ef3c42e4e..da9bccfaf391 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) {