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authorNamhyung Kim <namhyung.kim@lge.com>2013-11-25 13:42:47 +0900
committerSteven Rostedt <rostedt@goodmis.org>2014-01-02 20:57:05 -0500
commitb7e0bf341f6cfa92ae0a0e3d0c3496729595e1e9 (patch)
tree0831ae7ab363f3789c5cb14bbf4973bfe17287bc /kernel/trace/trace_probe.c
parent72fd293aa9ae8f4f48d6042be43fe81551c639f2 (diff)
downloadop-kernel-dev-b7e0bf341f6cfa92ae0a0e3d0c3496729595e1e9.zip
op-kernel-dev-b7e0bf341f6cfa92ae0a0e3d0c3496729595e1e9.tar.gz
tracing/uprobes: Add @+file_offset fetch method
Enable to fetch data from a file offset. Currently it only supports fetching from same binary uprobe set. It'll translate the file offset to a proper virtual address in the process. The syntax is "@+OFFSET" as it does similar to normal memory fetching (@ADDR) which does no address translation. Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'kernel/trace/trace_probe.c')
-rw-r--r--kernel/trace/trace_probe.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index a130d61..8364a42 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -374,7 +374,7 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
}
break;
- case '@': /* memory or symbol */
+ case '@': /* memory, file-offset or symbol */
if (isdigit(arg[1])) {
ret = kstrtoul(arg + 1, 0, &param);
if (ret)
@@ -382,6 +382,17 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
f->fn = t->fetch[FETCH_MTD_memory];
f->data = (void *)param;
+ } else if (arg[1] == '+') {
+ /* kprobes don't support file offsets */
+ if (is_kprobe)
+ return -EINVAL;
+
+ ret = kstrtol(arg + 2, 0, &offset);
+ if (ret)
+ break;
+
+ f->fn = t->fetch[FETCH_MTD_file_offset];
+ f->data = (void *)offset;
} else {
/* uprobes don't support symbols */
if (!is_kprobe)
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