From 8b658df206586f85cf19097068660203fa1253bd Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Thu, 25 Sep 2025 09:56:47 +0900 Subject: [PATCH] tracing: uprobes: Cleanup __trace_uprobe_create() with __free() Use __free() to cleanup ugly gotos in __trace_uprobe_create(). Link: https://lore.kernel.org/all/175509540482.193596.6541098946023873304.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_uprobe.c | 68 ++++++++++++++----------------------- 1 file changed, 26 insertions(+), 42 deletions(-) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index b3d39b5b0690..d1d9abbe6248 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -533,22 +533,25 @@ static int register_trace_uprobe(struct trace_uprobe *tu) return ret; } +DEFINE_FREE(free_trace_uprobe, struct trace_uprobe *, if (_T) free_trace_uprobe(_T)) + /* * Argument syntax: * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS] */ static int __trace_uprobe_create(int argc, const char **argv) { + struct trace_uprobe *tu __free(free_trace_uprobe) = NULL; const char *trlog __free(trace_probe_log_clear) = NULL; const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; - char *arg, *filename, *rctr, *rctr_end, *tmp; + struct path path __free(path_put) = {}; unsigned long offset, ref_ctr_offset; + char *filename __free(kfree) = NULL; + char *arg, *rctr, *rctr_end, *tmp; char *gbuf __free(kfree) = NULL; char *buf __free(kfree) = NULL; enum probe_print_type ptype; - struct trace_uprobe *tu; bool is_return = false; - struct path path; int i, ret; ref_ctr_offset = 0; @@ -586,10 +589,8 @@ static int __trace_uprobe_create(int argc, const char **argv) /* Find the last occurrence, in case the path contains ':' too. */ arg = strrchr(filename, ':'); - if (!arg || !isdigit(arg[1])) { - kfree(filename); + if (!arg || !isdigit(arg[1])) return -ECANCELED; - } trace_probe_log_set_index(1); /* filename is the 2nd argument */ @@ -597,13 +598,11 @@ static int __trace_uprobe_create(int argc, const char **argv) ret = kern_path(filename, LOOKUP_FOLLOW, &path); if (ret) { trace_probe_log_err(0, FILE_NOT_FOUND); - kfree(filename); return ret; } if (!d_is_reg(path.dentry)) { trace_probe_log_err(0, NO_REGULAR_FILE); - ret = -EINVAL; - goto fail_address_parse; + return -EINVAL; } /* Parse reference counter offset if specified. */ @@ -611,16 +610,14 @@ static int __trace_uprobe_create(int argc, const char **argv) if (rctr) { rctr_end = strchr(rctr, ')'); if (!rctr_end) { - ret = -EINVAL; rctr_end = rctr + strlen(rctr); trace_probe_log_err(rctr_end - filename, REFCNT_OPEN_BRACE); - goto fail_address_parse; + return -EINVAL; } else if (rctr_end[1] != '\0') { - ret = -EINVAL; trace_probe_log_err(rctr_end + 1 - filename, BAD_REFCNT_SUFFIX); - goto fail_address_parse; + return -EINVAL; } *rctr++ = '\0'; @@ -628,7 +625,7 @@ static int __trace_uprobe_create(int argc, const char **argv) ret = kstrtoul(rctr, 0, &ref_ctr_offset); if (ret) { trace_probe_log_err(rctr - filename, BAD_REFCNT); - goto fail_address_parse; + return ret; } } @@ -640,8 +637,7 @@ static int __trace_uprobe_create(int argc, const char **argv) is_return = true; } else { trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX); - ret = -EINVAL; - goto fail_address_parse; + return -EINVAL; } } @@ -649,7 +645,7 @@ static int __trace_uprobe_create(int argc, const char **argv) ret = kstrtoul(arg, 0, &offset); if (ret) { trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS); - goto fail_address_parse; + return ret; } /* setup a probe */ @@ -657,12 +653,12 @@ static int __trace_uprobe_create(int argc, const char **argv) if (event) { gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL); if (!gbuf) - goto fail_mem; + return -ENOMEM; ret = traceprobe_parse_event_name(&event, &group, gbuf, event - argv[0]); if (ret) - goto fail_address_parse; + return ret; } if (!event) { @@ -671,7 +667,7 @@ static int __trace_uprobe_create(int argc, const char **argv) tail = kstrdup(kbasename(filename), GFP_KERNEL); if (!tail) - goto fail_mem; + return -ENOMEM; ptr = strpbrk(tail, ".-_"); if (ptr) @@ -679,7 +675,7 @@ static int __trace_uprobe_create(int argc, const char **argv) buf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL); if (!buf) - goto fail_mem; + return -ENOMEM; snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); event = buf; kfree(tail); @@ -693,49 +689,37 @@ static int __trace_uprobe_create(int argc, const char **argv) ret = PTR_ERR(tu); /* This must return -ENOMEM otherwise there is a bug */ WARN_ON_ONCE(ret != -ENOMEM); - goto fail_address_parse; + return ret; } tu->offset = offset; tu->ref_ctr_offset = ref_ctr_offset; tu->path = path; - tu->filename = filename; + /* Clear @path so that it will not freed by path_put() */ + memset(&path, 0, sizeof(path)); + tu->filename = no_free_ptr(filename); /* parse arguments */ for (i = 0; i < argc; i++) { struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) = kzalloc(sizeof(*ctx), GFP_KERNEL); - if (!ctx) { - ret = -ENOMEM; - goto error; - } + if (!ctx) + return -ENOMEM; ctx->flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER; trace_probe_log_set_index(i + 2); ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], ctx); if (ret) - goto error; + return ret; } ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; ret = traceprobe_set_print_fmt(&tu->tp, ptype); if (ret < 0) - goto error; + return ret; ret = register_trace_uprobe(tu); if (!ret) - goto out; - -error: - free_trace_uprobe(tu); -out: - return ret; - -fail_mem: - ret = -ENOMEM; - -fail_address_parse: - path_put(&path); - kfree(filename); + tu = NULL; return ret; }