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samples/bpf: fix kprobe attachment issue on x64

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Commit d5a00528b5 ("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: d5a00528b5 ("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>
This commit is contained in:
Yonghong Song 2018-04-29 19:27:48 -07:00 committed by Alexei Starovoitov
parent 7ef3771205
commit 34745aed51
1 changed files with 26 additions and 8 deletions
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34
samples/bpf/bpf_load.c
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@ -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) {