In 293d5b4394 ("perf probe: Support probing on offline cross-arch binary")
DWARF register tables were introduced for many architectures, with the one for
the "dx" register being broken for x86_64, which got noticed by the 'perf test
bpf' testcase, that has this difference from a successful run to one that
fails, with the aforementioned patch:
-Writing event: p:perf_bpf_probe/func _text+5197232 f_mode=+68(%di):x32 offset=%si:s64 orig=dx:s32
-Failed to write event: Invalid argument
-bpf_probe: failed to apply perf probe eventsFailed to add events selected by BPF
+Writing event: p:perf_bpf_probe/func _text+5197232 f_mode=+68(%di):x32 offset=%si:s64 orig=%dx:s32
Add the missing '%' to '%dx' to fix this.
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 293d5b4394 ("perf probe: Support probing on offline cross-arch binary")
Link: https://lkml.kernel.org/r/20160909145955.GC32585@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support probing on offline cross-architecture binary by adding getting
the target machine arch from ELF and choose correct register string for
the machine.
Here is an example:
-----
$ perf probe --vmlinux=./vmlinux-arm --definition 'do_sys_open $params'
p:probe/do_sys_open do_sys_open+0 dfd=%r5:s32 filename=%r1:u32 flags=%r6:s32 mode=%r3:u16
-----
Here, we can get probe/do_sys_open from above and append it to to the target
machine's tracing/kprobe_events file in the tracefs mountput, usually
/sys/kernel/debug/tracing/kprobe_events (or /sys/kernel/tracing/kprobe_events).
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147214229717.23638.6440579792548044658.stgit@devbox
[ Add definition for EM_AARCH64 to fix the build on at least centos 6, debian 7 & ubuntu 12.04.5 ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo
Masami Hiramatsu