[PATCH] tracing/kprobes: allow to create probe with a module name starting with a digit

[Sabrina Dubroca]

Always try to parse an address, since kstrtoul() will safely fail when
given a symbol as input. If that fails (which will be the case for a
symbol), try to parse a symbol instead.

This allows creating a probe such as:

    p:probe/vlan_gro_receive 8021q:vlan_gro_receive+0

Which is necessary for this command to work:

    perf probe -m 8021q -a vlan_gro_receive

Signed-off-by: Sabrina Dubroca <s...@queasysnail.net>
---
 kernel/trace/trace_kprobe.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c129fca6ec99..b53c8d369163 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -707,20 +707,16 @@ static int create_trace_kprobe(int argc, char **argv)
                pr_info("Probe point is not specified.\n");
                return -EINVAL;
        }
-       if (isdigit(argv[1][0])) {
-               /* an address specified */
-               ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr);
-               if (ret) {
-                       pr_info("Failed to parse address.\n");
-                       return ret;
-               }
-       } else {
+
+       /* try to parse an address. if that fails, try to read the
+        * input as a symbol. */
+       if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
                /* a symbol specified */
                symbol = argv[1];
                /* TODO: support .init module functions */
                ret = traceprobe_split_symbol_offset(symbol, &offset);
                if (ret) {
-                       pr_info("Failed to parse symbol.\n");
+                       pr_info("Failed to parse either an address or a 
symbol.\n");
                        return ret;
                }
                if (offset && is_return &&
-- 
2.13.1