tracing: Adopt __free() and guard() for trace_fprobe.c

Adopt __free() and guard() for trace_fprobe.c to remove gotos.

Link: https://lore.kernel.org/all/173643302228.1514810.2053430844068447947.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu (Google) 2025-01-09 23:30:22 +09:00
parent 927054606d
commit ff246f27d4

View File

@ -379,6 +379,9 @@ static void free_trace_fprobe(struct trace_fprobe *tf)
}
}
/* Since alloc_trace_fprobe() can return error, check the pointer is ERR too. */
DEFINE_FREE(free_trace_fprobe, struct trace_fprobe *, if (!IS_ERR_OR_NULL(_T)) free_trace_fprobe(_T))
/*
* Allocate new trace_probe and initialize it (including fprobe).
*/
@ -390,7 +393,7 @@ static struct trace_fprobe *alloc_trace_fprobe(const char *group,
int maxactive,
int nargs, bool is_return)
{
struct trace_fprobe *tf;
struct trace_fprobe *tf __free(free_trace_fprobe) = NULL;
int ret = -ENOMEM;
tf = kzalloc(struct_size(tf, tp.args, nargs), GFP_KERNEL);
@ -399,7 +402,7 @@ static struct trace_fprobe *alloc_trace_fprobe(const char *group,
tf->symbol = kstrdup(symbol, GFP_KERNEL);
if (!tf->symbol)
goto error;
return ERR_PTR(-ENOMEM);
if (is_return)
tf->fp.exit_handler = fexit_dispatcher;
@ -412,13 +415,10 @@ static struct trace_fprobe *alloc_trace_fprobe(const char *group,
ret = trace_probe_init(&tf->tp, event, group, false, nargs);
if (ret < 0)
goto error;
return ERR_PTR(ret);
dyn_event_init(&tf->devent, &trace_fprobe_ops);
return tf;
error:
free_trace_fprobe(tf);
return ERR_PTR(ret);
return_ptr(tf);
}
static struct trace_fprobe *find_trace_fprobe(const char *event,
@ -845,14 +845,12 @@ static int register_trace_fprobe(struct trace_fprobe *tf)
struct trace_fprobe *old_tf;
int ret;
mutex_lock(&event_mutex);
guard(mutex)(&event_mutex);
old_tf = find_trace_fprobe(trace_probe_name(&tf->tp),
trace_probe_group_name(&tf->tp));
if (old_tf) {
ret = append_trace_fprobe(tf, old_tf);
goto end;
}
if (old_tf)
return append_trace_fprobe(tf, old_tf);
/* Register new event */
ret = register_fprobe_event(tf);
@ -862,7 +860,7 @@ static int register_trace_fprobe(struct trace_fprobe *tf)
trace_probe_log_err(0, EVENT_EXIST);
} else
pr_warn("Failed to register probe event(%d)\n", ret);
goto end;
return ret;
}
/* Register fprobe */
@ -872,8 +870,6 @@ static int register_trace_fprobe(struct trace_fprobe *tf)
else
dyn_event_add(&tf->devent, trace_probe_event_call(&tf->tp));
end:
mutex_unlock(&event_mutex);
return ret;
}
@ -1034,7 +1030,10 @@ static int parse_symbol_and_return(int argc, const char *argv[],
return 0;
}
static int __trace_fprobe_create(int argc, const char *argv[])
DEFINE_FREE(module_put, struct module *, if (_T) module_put(_T))
static int trace_fprobe_create_internal(int argc, const char *argv[],
struct traceprobe_parse_context *ctx)
{
/*
* Argument syntax:
@ -1060,24 +1059,21 @@ static int __trace_fprobe_create(int argc, const char *argv[])
* Type of args:
* FETCHARG:TYPE : use TYPE instead of unsigned long.
*/
struct trace_fprobe *tf = NULL;
struct trace_fprobe *tf __free(free_trace_fprobe) = NULL;
int i, len, new_argc = 0, ret = 0;
bool is_return = false;
char *symbol = NULL;
char *symbol __free(kfree) = NULL;
const char *event = NULL, *group = FPROBE_EVENT_SYSTEM;
const char **new_argv = NULL;
const char **new_argv __free(kfree) = NULL;
int maxactive = 0;
char buf[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
char sbuf[KSYM_NAME_LEN];
char abuf[MAX_BTF_ARGS_LEN];
char *dbuf = NULL;
char *dbuf __free(kfree) = NULL;
bool is_tracepoint = false;
struct module *tp_mod = NULL;
struct module *tp_mod __free(module_put) = NULL;
struct tracepoint *tpoint = NULL;
struct traceprobe_parse_context ctx = {
.flags = TPARG_FL_KERNEL | TPARG_FL_FPROBE,
};
if ((argv[0][0] != 'f' && argv[0][0] != 't') || argc < 2)
return -ECANCELED;
@ -1087,8 +1083,6 @@ static int __trace_fprobe_create(int argc, const char *argv[])
group = TRACEPOINT_EVENT_SYSTEM;
}
trace_probe_log_init("trace_fprobe", argc, argv);
event = strchr(&argv[0][1], ':');
if (event)
event++;
@ -1100,21 +1094,21 @@ static int __trace_fprobe_create(int argc, const char *argv[])
len = strlen(&argv[0][1]);
if (len > MAX_EVENT_NAME_LEN - 1) {
trace_probe_log_err(1, BAD_MAXACT);
goto parse_error;
return -EINVAL;
}
memcpy(buf, &argv[0][1], len);
buf[len] = '\0';
ret = kstrtouint(buf, 0, &maxactive);
if (ret || !maxactive) {
trace_probe_log_err(1, BAD_MAXACT);
goto parse_error;
return -EINVAL;
}
/* 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;
return -EINVAL;
}
}
@ -1123,12 +1117,12 @@ static int __trace_fprobe_create(int argc, const char *argv[])
/* a symbol(or tracepoint) must be specified */
ret = parse_symbol_and_return(argc, argv, &symbol, &is_return, is_tracepoint);
if (ret < 0)
goto parse_error;
return -EINVAL;
if (!is_return && maxactive) {
trace_probe_log_set_index(0);
trace_probe_log_err(1, BAD_MAXACT_TYPE);
goto parse_error;
return -EINVAL;
}
trace_probe_log_set_index(0);
@ -1136,7 +1130,7 @@ static int __trace_fprobe_create(int argc, const char *argv[])
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto parse_error;
return -EINVAL;
}
if (!event) {
@ -1152,49 +1146,44 @@ static int __trace_fprobe_create(int argc, const char *argv[])
}
if (is_return)
ctx.flags |= TPARG_FL_RETURN;
ctx->flags |= TPARG_FL_RETURN;
else
ctx.flags |= TPARG_FL_FENTRY;
ctx->flags |= TPARG_FL_FENTRY;
if (is_tracepoint) {
ctx.flags |= TPARG_FL_TPOINT;
ctx->flags |= TPARG_FL_TPOINT;
tpoint = find_tracepoint(symbol, &tp_mod);
if (tpoint) {
ctx.funcname = kallsyms_lookup(
ctx->funcname = kallsyms_lookup(
(unsigned long)tpoint->probestub,
NULL, NULL, NULL, sbuf);
} else if (IS_ENABLED(CONFIG_MODULES)) {
/* This *may* be loaded afterwards */
tpoint = TRACEPOINT_STUB;
ctx.funcname = symbol;
ctx->funcname = symbol;
} else {
trace_probe_log_set_index(1);
trace_probe_log_err(0, NO_TRACEPOINT);
goto parse_error;
return -EINVAL;
}
} else
ctx.funcname = symbol;
ctx->funcname = symbol;
argc -= 2; argv += 2;
new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc,
abuf, MAX_BTF_ARGS_LEN, &ctx);
if (IS_ERR(new_argv)) {
ret = PTR_ERR(new_argv);
new_argv = NULL;
goto out;
}
abuf, MAX_BTF_ARGS_LEN, ctx);
if (IS_ERR(new_argv))
return PTR_ERR(new_argv);
if (new_argv) {
argc = new_argc;
argv = new_argv;
}
if (argc > MAX_TRACE_ARGS) {
ret = -E2BIG;
goto out;
}
if (argc > MAX_TRACE_ARGS)
return -E2BIG;
ret = traceprobe_expand_dentry_args(argc, argv, &dbuf);
if (ret)
goto out;
return ret;
/* setup a probe */
tf = alloc_trace_fprobe(group, event, symbol, tpoint, tp_mod,
@ -1203,16 +1192,16 @@ static int __trace_fprobe_create(int argc, const char *argv[])
ret = PTR_ERR(tf);
/* This must return -ENOMEM, else there is a bug */
WARN_ON_ONCE(ret != -ENOMEM);
goto out; /* We know tf is not allocated */
return ret;
}
/* parse arguments */
for (i = 0; i < argc; i++) {
trace_probe_log_set_index(i + 2);
ctx.offset = 0;
ret = traceprobe_parse_probe_arg(&tf->tp, i, argv[i], &ctx);
ctx->offset = 0;
ret = traceprobe_parse_probe_arg(&tf->tp, i, argv[i], ctx);
if (ret)
goto error; /* This can be -ENOMEM */
return ret; /* This can be -ENOMEM */
}
if (is_return && tf->tp.entry_arg) {
@ -1223,7 +1212,7 @@ static int __trace_fprobe_create(int argc, const char *argv[])
ret = traceprobe_set_print_fmt(&tf->tp,
is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL);
if (ret < 0)
goto error;
return ret;
ret = register_trace_fprobe(tf);
if (ret) {
@ -1234,29 +1223,32 @@ static int __trace_fprobe_create(int argc, const char *argv[])
trace_probe_log_err(0, BAD_PROBE_ADDR);
else if (ret != -ENOMEM && ret != -EEXIST)
trace_probe_log_err(0, FAIL_REG_PROBE);
goto error;
return -EINVAL;
}
out:
if (tp_mod)
module_put(tp_mod);
/* 'tf' is successfully registered. To avoid freeing, assign NULL. */
tf = NULL;
return 0;
}
static int trace_fprobe_create_cb(int argc, const char *argv[])
{
struct traceprobe_parse_context ctx = {
.flags = TPARG_FL_KERNEL | TPARG_FL_FPROBE,
};
int ret;
trace_probe_log_init("trace_fprobe", argc, argv);
ret = trace_fprobe_create_internal(argc, argv, &ctx);
traceprobe_finish_parse(&ctx);
trace_probe_log_clear();
kfree(new_argv);
kfree(symbol);
kfree(dbuf);
return ret;
parse_error:
ret = -EINVAL;
error:
free_trace_fprobe(tf);
goto out;
}
static int trace_fprobe_create(const char *raw_command)
{
return trace_probe_create(raw_command, __trace_fprobe_create);
return trace_probe_create(raw_command, trace_fprobe_create_cb);
}
static int trace_fprobe_release(struct dyn_event *ev)