[PATCH v13 16/20] tracing/fprobe: Remove nr_maxactive from fprobe

Masami Hiramatsu (Google)
2024-08-18T12:50:45Z

Remove depercated fprobe::nr_maxactive. This involves fprobe events to
rejects the maxactive number.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
Changes in v2:
- Newly added.
---
include/linux/fprobe.h | 2 --
kernel/trace/trace_fprobe.c | 44 ++++++-------------------------------------
2 files changed, 6 insertions(+), 40 deletions(-)

diff --git a/include/linux/fprobe.h b/include/linux/fprobe.h
index 2d06bbd99601..a86b3e4df2a0 100644
--- a/include/linux/fprobe.h
+++ b/include/linux/fprobe.h
@@ -54,7 +54,6 @@ struct fprobe_hlist {
* @nmissed: The counter for missing events.
* @flags: The status flag.
* @entry_data_size: The private data storage size.
- * @nr_maxactive: The max number of active functions. (*deprecated)
* @entry_handler: The callback function for function entry.
* @exit_handler: The callback function for function exit.
* @hlist_array: The fprobe_hlist for fprobe search from IP hash table.
@@ -63,7 +62,6 @@ struct fprobe {
unsigned long nmissed;
unsigned int flags;
size_t entry_data_size;
- int nr_maxactive;

fprobe_entry_cb entry_handler;
fprobe_exit_cb exit_handler;
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index 86cd6a8c806a..20ef5cd5d419 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -422,7 +422,6 @@ static struct trace_fprobe *alloc_trace_fprobe(const char *group,
const char *event,
const char *symbol,
struct tracepoint *tpoint,
- int maxactive,
int nargs, bool is_return)
{
struct trace_fprobe *tf;
@@ -442,7 +441,6 @@ static struct trace_fprobe *alloc_trace_fprobe(const char *group,
tf->fp.entry_handler = fentry_dispatcher;

tf->tpoint = tpoint;
- tf->fp.nr_maxactive = maxactive;

ret = trace_probe_init(&tf->tp, event, group, false, nargs);
if (ret < 0)
@@ -1021,12 +1019,11 @@ static int __trace_fprobe_create(int argc, const char *argv[])
* FETCHARG:TYPE : use TYPE instead of unsigned long.
*/
struct trace_fprobe *tf = NULL;
- int i, len, new_argc = 0, ret = 0;
+ int i, new_argc = 0, ret = 0;
bool is_return = false;
char *symbol = NULL;
const char *event = NULL, *group = FPROBE_EVENT_SYSTEM;
const char **new_argv = NULL;
- int maxactive = 0;
char buf[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
char sbuf[KSYM_NAME_LEN];
@@ -1048,33 +1045,13 @@ static int __trace_fprobe_create(int argc, const char *argv[])

trace_probe_log_init("trace_fprobe", argc, argv);

- event = strchr(&argv[0][1], ':');
- if (event)
- event++;
-
- if (isdigit(argv[0][1])) {
- if (event)
- len = event - &argv[0][1] - 1;
- else
- len = strlen(&argv[0][1]);
- if (len > MAX_EVENT_NAME_LEN - 1) {
- trace_probe_log_err(1, BAD_MAXACT);
- goto parse_error;
- }
- memcpy(buf, &argv[0][1], len);
- buf[len] = '\0';
- ret = kstrtouint(buf, 0, &maxactive);
- if (ret || !maxactive) {
+ if (argv[0][1] != '\0') {
+ if (argv[0][1] != ':') {
+ trace_probe_log_set_index(0);
trace_probe_log_err(1, BAD_MAXACT);
goto parse_error;
}
- /* fprobe rethook instances are iterated over via a list. The
- * maximum should stay reasonable.
- */
- if (maxactive > RETHOOK_MAXACTIVE_MAX) {
- trace_probe_log_err(1, MAXACT_TOO_BIG);
- goto parse_error;
- }
+ event = &argv[0][2];
}

trace_probe_log_set_index(1);
@@ -1084,12 +1061,6 @@ static int __trace_fprobe_create(int argc, const char *argv[])
if (ret < 0)
goto parse_error;

- if (!is_return && maxactive) {
- trace_probe_log_set_index(0);
- trace_probe_log_err(1, BAD_MAXACT_TYPE);
- goto parse_error;
- }
-
trace_probe_log_set_index(0);
if (event) {
ret = traceprobe_parse_event_name(&event, &group, gbuf,
@@ -1147,8 +1118,7 @@ static int __trace_fprobe_create(int argc, const char *argv[])
goto out;

/* setup a probe */
- tf = alloc_trace_fprobe(group, event, symbol, tpoint, maxactive,
- argc, is_return);
+ tf = alloc_trace_fprobe(group, event, symbol, tpoint, argc, is_return);
if (IS_ERR(tf)) {
ret = PTR_ERR(tf);
/* This must return -ENOMEM, else there is a bug */
@@ -1230,8 +1200,6 @@ static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev)
seq_putc(m, 't');
else
seq_putc(m, 'f');
- if (trace_fprobe_is_return(tf) && tf->fp.nr_maxactive)
- seq_printf(m, "%d", tf->fp.nr_maxactive);
seq_printf(m, ":%s/%s", trace_probe_group_name(&tf->tp),
trace_probe_name(&tf->tp));