[ktap] [PATCH 2/3] uprobes,sdt: add all events for all matched symbols/notes
- From: Azat Khuzhin <a3at.mail@xxxxxxxxx>
- To: ktap@xxxxxxxxxxxxx
- Date: Wed, 13 Nov 2013 23:13:36 +0400
Not only for first one.
As Jovi, noticed for example:
mulitple probe location with same sdt name
For example(in my x86-64 machine):
#readelf -n /lib64/libc.so.6 | grep lll_futex_wake
Name: lll_futex_wake
Name: lll_futex_wake
After this patch events will be added for both sdt notes.
Signed-off-by: Azat Khuzhin <a3at.mail@xxxxxxxxx>
---
userspace/eventdef.c | 114 +++++++++++++++++++++++++++------------------------
1 file changed, 61 insertions(+), 53 deletions(-)
diff --git a/userspace/eventdef.c b/userspace/eventdef.c
index 13703c6..41f09fd 100644
--- a/userspace/eventdef.c
+++ b/userspace/eventdef.c
@@ -304,51 +304,92 @@ static int parse_events_add_kprobe(char *old_event)
return 0;
}
+#define UPROBE_EVENTS_PATH "/sys/kernel/debug/tracing/uprobe_events"
+
+/**
+ * @return 1 on success, otherwise 0
+ */
+static int
+write_uprobe_event(int fd, int ret, int seq, const char *binary, size_t addr)
+{
+ char probe_event[128] = {0};
+
+ if (ret)
+ snprintf(probe_event, 128, "r:uprobes/kp%d %s:0x%lx", seq,
binary, addr);
+ else
+ snprintf(probe_event, 128, "p:uprobes/kp%d %s:0x%lx", seq,
binary, addr);
+
+ verbose_printf("uprobe event %s\n", probe_event);
+ if (write(fd, probe_event, strlen(probe_event)) <= 0) {
+ fprintf(stderr, "Cannot write %s to %s\n", probe_event,
+ UPROBE_EVENTS_PATH);
+ return 0;
+ }
+
+ return 1;
+}
+
+/**
+ * TODO: avoid copy-paste stuff
+ *
+ * @return 1 on success, otherwise 0
+ */
#ifdef NO_LIBELF
-static char *parse_events_resolve_symbol(char *event, int type)
+static int parse_events_resolve_symbol(int fd, int seq, char *event, int type)
{
char *colon;
+ char *binary;
unsigned long symbol_address;
colon = strchr(event, ':');
if (!colon)
- return event;
+ return 0;
symbol_address = strtol(colon + 1 /* skip ":" */, NULL, 0);
/**
* We already have address, no need in resolving.
*/
- if (symbol_address)
- return event;
+ if (symbol_address) {
+ int ret;
+
+ binary = strndup(event, colon - event);
+ ret = write_uprobe_event(fd, !!strstr(event, "%return"), seq,
+ binary, symbol_address);
+ free(binary);
+
+ return ret;
+ }
fprintf(stderr, "error: cannot resolve event \"%s\" without libelf, "
"please recompile ktap with NO_LIBELF disabled\n",
event);
exit(EXIT_FAILURE);
- return NULL;
+ return 0;
}
#else
-static char *parse_events_resolve_symbol(char *event, int type)
+static int parse_events_resolve_symbol(int fd, int seq, char *event, int type)
{
char *colon, *end, *tail, *binary, *symbol;
+ char *r;
vaddr_t symbol_address;
struct dso_symbol *symbols = NULL;
size_t symbols_count, i;
+ int ret = 0;
colon = strchr(event, ':');
if (!colon)
- return event;
+ return 0;
+ r = strstr(event, "%return");
symbol_address = strtol(colon + 1 /* skip ":" */, NULL, 0);
+ binary = strndup(event, colon - event);
/**
* We already have address, no need in resolving.
*/
if (symbol_address)
- return event;
-
- binary = strndup(event, colon - event);
+ return write_uprobe_event(fd, !!r, seq, binary, symbol_address);
end = strpbrk(event, "% ");
if (end) {
@@ -361,23 +402,21 @@ static char *parse_events_resolve_symbol(char *event, int
type)
symbols_count = get_dso_symbols(&symbols, binary, type);
for (i = 0; i < symbols_count; ++i) {
+
if (strcmp(symbols[i].name, symbol))
continue;
symbol_address = symbols[i].addr;
- break;
- }
- free_dso_symbols(symbols, symbols_count);
- if (symbol_address) {
verbose_printf("symbol %s resolved to 0x%lx\n",
event, symbol_address);
+ ret = write_uprobe_event(fd, !!r, seq, binary, symbol_address);
+ if (!ret)
+ break;
+ }
+ free_dso_symbols(symbols, symbols_count);
- event = realloc(event,
- strlen(event) + (strlen(STRINGIFY(ULONG_MAX))));
- sprintf(event, "%s:0x%lx%s",
- binary, symbol_address, tail ?: "");
- } else {
+ if (!ret) {
fprintf(stderr, "error: cannot find symbol %s in binary %s\n",
symbol, binary);
exit(EXIT_FAILURE);
@@ -388,22 +427,17 @@ static char *parse_events_resolve_symbol(char *event, int
type)
if (tail)
free(tail);
- return event;
+ return ret;
}
#endif
-#define UPROBE_EVENTS_PATH "/sys/kernel/debug/tracing/uprobe_events"
-
static int parse_events_add_uprobe(char *old_event, int type)
{
static int event_seq = 0;
struct probe_list *pl;
- char probe_event[128] = {0};
char event_id_path[128] = {0};
- char *event;
- char *r;
- int fd;
int ret;
+ int fd;
fd = open(UPROBE_EVENTS_PATH, O_WRONLY);
if (fd < 0) {
@@ -411,33 +445,7 @@ static int parse_events_add_uprobe(char *old_event, int
type)
return -1;
}
- event = strdup(old_event);
-
- /* resolve symbol with libelf help */
- event = parse_events_resolve_symbol(event, type);
-
- r = strstr(event, "%return");
- if (r) {
- memset(r, ' ', 7);
- }
-
- if (r) {
- snprintf(probe_event, 128, "r:uprobes/kp%d %s",
- event_seq, event);
- } else
- snprintf(probe_event, 128, "p:uprobes/kp%d %s",
- event_seq, event);
-
- free(event);
-
- verbose_printf("uprobe event %s\n", probe_event);
- ret = write(fd, probe_event, strlen(probe_event));
- if (ret <= 0) {
- fprintf(stderr, "Cannot write %s to %s\n", probe_event,
- UPROBE_EVENTS_PATH);
- close(fd);
- return -1;
- }
+ parse_events_resolve_symbol(fd, event_seq, old_event, type);
close(fd);
--
1.8.4.rc3
Other related posts:
- » [ktap] [PATCH 2/3] uprobes,sdt: add all events for all matched symbols/notes - Azat Khuzhin
