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tracing/kprobes: Simplify __trace_kprobe_create() by removing gotos

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Simplify __trace_kprobe_create() by removing gotos.

Link: https://lore.kernel.org/all/173643301102.1514810.6149004416601259466.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 23:30:11 +09:00
parent 7dcc352078
commit 927054606d
1 changed files with 49 additions and 48 deletions
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kernel/trace/trace_kprobe.c
+49 -48
View File
@@ -836,7 +836,8 @@ out:
static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
struct pt_regs *regs);
static int __trace_kprobe_create(int argc, const char *argv[])
static int trace_kprobe_create_internal(int argc, const char *argv[],
struct traceprobe_parse_context *ctx)
{
/*
* Argument syntax:
@@ -877,7 +878,6 @@ static int __trace_kprobe_create(int argc, const char *argv[])
char gbuf[MAX_EVENT_NAME_LEN];
char abuf[MAX_BTF_ARGS_LEN];
char *dbuf __free(kfree) = NULL;
struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL };
switch (argv[0][0]) {
case 'r':
@@ -891,8 +891,6 @@ static int __trace_kprobe_create(int argc, const char *argv[])
if (argc < 2)
return -ECANCELED;
trace_probe_log_init("trace_kprobe", argc, argv);
event = strchr(&argv[0][1], ':');
if (event)
event++;
@@ -900,7 +898,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
if (isdigit(argv[0][1])) {
if (!is_return) {
trace_probe_log_err(1, BAD_MAXACT_TYPE);
goto parse_error;
return -EINVAL;
}
if (event)
len = event - &argv[0][1] - 1;
@@ -908,21 +906,21 @@ static int __trace_kprobe_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;
}
/* kretprobes instances are iterated over via a list. The
* maximum should stay reasonable.
*/
if (maxactive > KRETPROBE_MAXACTIVE_MAX) {
trace_probe_log_err(1, MAXACT_TOO_BIG);
goto parse_error;
return -EINVAL;
}
}
@@ -931,16 +929,13 @@ static int __trace_kprobe_create(int argc, const char *argv[])
if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) {
trace_probe_log_set_index(1);
/* Check whether uprobe event specified */
if (strchr(argv[1], '/') && strchr(argv[1], ':')) {
ret = -ECANCELED;
goto out;
}
if (strchr(argv[1], '/') && strchr(argv[1], ':'))
return -ECANCELED;
/* a symbol specified */
symbol = kstrdup(argv[1], GFP_KERNEL);
if (!symbol) {
ret = -ENOMEM;
goto out;
}
if (!symbol)
return -ENOMEM;
tmp = strchr(symbol, '%');
if (tmp) {
@@ -949,7 +944,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
is_return = true;
} else {
trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
goto parse_error;
return -EINVAL;
}
}
@@ -957,7 +952,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
ret = traceprobe_split_symbol_offset(symbol, &offset);
if (ret || offset < 0 || offset > UINT_MAX) {
trace_probe_log_err(0, BAD_PROBE_ADDR);
goto parse_error;
return -EINVAL;
}
ret = validate_probe_symbol(symbol);
if (ret) {
@@ -965,17 +960,17 @@ static int __trace_kprobe_create(int argc, const char *argv[])
trace_probe_log_err(0, NON_UNIQ_SYMBOL);
else
trace_probe_log_err(0, BAD_PROBE_ADDR);
goto parse_error;
return -EINVAL;
}
if (is_return)
ctx.flags |= TPARG_FL_RETURN;
ctx->flags |= TPARG_FL_RETURN;
ret = kprobe_on_func_entry(NULL, symbol, offset);
if (ret == 0 && !is_return)
ctx.flags |= TPARG_FL_FENTRY;
ctx->flags |= TPARG_FL_FENTRY;
/* Defer the ENOENT case until register kprobe */
if (ret == -EINVAL && is_return) {
trace_probe_log_err(0, BAD_RETPROBE);
goto parse_error;
return -EINVAL;
}
}
@@ -984,7 +979,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto parse_error;
return ret;
}
if (!event) {
@@ -1000,26 +995,24 @@ static int __trace_kprobe_create(int argc, const char *argv[])
}
argc -= 2; argv += 2;
ctx.funcname = symbol;
ctx->funcname = symbol;
new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc,
abuf, MAX_BTF_ARGS_LEN, &ctx);
abuf, MAX_BTF_ARGS_LEN, ctx);
if (IS_ERR(new_argv)) {
ret = PTR_ERR(new_argv);
new_argv = NULL;
goto out;
return ret;
}
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 */
tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
@@ -1028,16 +1021,16 @@ static int __trace_kprobe_create(int argc, const char *argv[])
ret = PTR_ERR(tk);
/* This must return -ENOMEM, else there is a bug */
WARN_ON_ONCE(ret != -ENOMEM);
goto out; /* We know tk is not allocated */
return ret; /* We know tk is not allocated */
}
/* parse arguments */
for (i = 0; i < argc; i++) {
trace_probe_log_set_index(i + 2);
ctx.offset = 0;
ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], &ctx);
ctx->offset = 0;
ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], ctx);
if (ret)
goto out; /* This can be -ENOMEM */
return ret; /* This can be -ENOMEM */
}
/* entry handler for kretprobe */
if (is_return && tk->tp.entry_arg) {
@@ -1048,7 +1041,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
ret = traceprobe_set_print_fmt(&tk->tp, ptype);
if (ret < 0)
goto out;
return ret;
ret = register_trace_kprobe(tk);
if (ret) {
@@ -1059,26 +1052,34 @@ static int __trace_kprobe_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);
} else
/*
* Here, 'tk' has been registered to the list successfully,
* so we don't need to free it.
*/
tk = NULL;
return ret;
}
/*
* Here, 'tk' has been registered to the list successfully,
* so we don't need to free it.
*/
tk = NULL;
return 0;
}
static int trace_kprobe_create_cb(int argc, const char *argv[])
{
struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL };
int ret;
trace_probe_log_init("trace_kprobe", argc, argv);
ret = trace_kprobe_create_internal(argc, argv, &ctx);
out:
traceprobe_finish_parse(&ctx);
trace_probe_log_clear();
return ret;
parse_error:
ret = -EINVAL;
goto out;
}
static int trace_kprobe_create(const char *raw_command)
{
return trace_probe_create(raw_command, __trace_kprobe_create);
return trace_probe_create(raw_command, trace_kprobe_create_cb);
}
static int create_or_delete_trace_kprobe(const char *raw_command)