Commit 7e465baa authored by Tom Zanussi's avatar Tom Zanussi Committed by Steven Rostedt (VMware)
Browse files

tracing: Make traceprobe parsing code reusable 

traceprobe_probes_write() and traceprobe_command() actually contain
nothing that ties them to kprobes - the code is generically useful for
similar types of parsing elsewhere, so separate it out and move it to
trace.c/trace.h.

Other than moving it, the only change is in naming:
traceprobe_probes_write() becomes trace_parse_run_command() and
traceprobe_command() becomes trace_run_command().

Link: http://lkml.kernel.org/r/ae5c26ea40c196a8986854d921eb6e713ede7e3f.1506105045.git.tom.zanussi@linux.intel.com



Signed-off-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 4f36c2d8

kernel/trace/trace.c

+86 −0
Original line number Diff line number Diff line
@@ -8281,6 +8281,92 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) 
}

EXPORT_SYMBOL_GPL(ftrace_dump);



int trace_run_command(const char *buf, int (*createfn)(int, char **))

{

	char **argv;

	int argc, ret;



	argc = 0;

	ret = 0;

	argv = argv_split(GFP_KERNEL, buf, &argc);

	if (!argv)

		return -ENOMEM;



	if (argc)

		ret = createfn(argc, argv);



	argv_free(argv);



	return ret;

}



#define WRITE_BUFSIZE  4096



ssize_t trace_parse_run_command(struct file *file, const char __user *buffer,

				size_t count, loff_t *ppos,

				int (*createfn)(int, char **))

{

	char *kbuf, *buf, *tmp;

	int ret = 0;

	size_t done = 0;

	size_t size;



	kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);

	if (!kbuf)

		return -ENOMEM;



	while (done < count) {

		size = count - done;



		if (size >= WRITE_BUFSIZE)

			size = WRITE_BUFSIZE - 1;



		if (copy_from_user(kbuf, buffer + done, size)) {

			ret = -EFAULT;

			goto out;

		}

		kbuf[size] = '\0';

		buf = kbuf;

		do {

			tmp = strchr(buf, '\n');

			if (tmp) {

				*tmp = '\0';

				size = tmp - buf + 1;

			} else {

				size = strlen(buf);

				if (done + size < count) {

					if (buf != kbuf)

						break;

					/* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */

					pr_warn("Line length is too long: Should be less than %d\n",

						WRITE_BUFSIZE - 2);

					ret = -EINVAL;

					goto out;

				}

			}

			done += size;



			/* Remove comments */

			tmp = strchr(buf, '#');



			if (tmp)

				*tmp = '\0';



			ret = trace_run_command(buf, createfn);

			if (ret)

				goto out;

			buf += size;



		} while (done < count);

	}

	ret = done;



out:

	kfree(kbuf);



	return ret;

}



__init static int tracer_alloc_buffers(void)

{

	int ring_buf_size;

kernel/trace/trace.h

+7 −0
Original line number Diff line number Diff line
@@ -1752,6 +1752,13 @@ void trace_printk_start_comm(void); 
int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);

int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);



#define MAX_EVENT_NAME_LEN	64



extern int trace_run_command(const char *buf, int (*createfn)(int, char**));

extern ssize_t trace_parse_run_command(struct file *file,

		const char __user *buffer, size_t count, loff_t *ppos,

		int (*createfn)(int, char**));



/*

 * Normal trace_printk() and friends allocates special buffers

 * to do the manipulation, as well as saves the print formats

kernel/trace/trace_kprobe.c

+9 −9
Original line number Diff line number Diff line
@@ -907,7 +907,7 @@ static int probes_open(struct inode *inode, struct file *file) 
static ssize_t probes_write(struct file *file, const char __user *buffer,

			    size_t count, loff_t *ppos)

{

	return traceprobe_probes_write(file, buffer, count, ppos,

	return trace_parse_run_command(file, buffer, count, ppos,

				       create_trace_kprobe);

}
@@ -1433,7 +1433,7 @@ static __init int kprobe_trace_self_tests_init(void) 


	pr_info("Testing kprobe tracing: ");



	ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "

	ret = trace_run_command("p:testprobe kprobe_trace_selftest_target "

				"$stack $stack0 +0($stack)",

				create_trace_kprobe);

	if (WARN_ON_ONCE(ret)) {
@@ -1455,7 +1455,7 @@ static __init int kprobe_trace_self_tests_init(void) 
		}

	}



	ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "

	ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target "

				"$retval", create_trace_kprobe);

	if (WARN_ON_ONCE(ret)) {

		pr_warn("error on probing function return.\n");
@@ -1526,13 +1526,13 @@ static __init int kprobe_trace_self_tests_init(void) 
			disable_trace_kprobe(tk, file);

	}



	ret = traceprobe_command("-:testprobe", create_trace_kprobe);

	ret = trace_run_command("-:testprobe", create_trace_kprobe);

	if (WARN_ON_ONCE(ret)) {

		pr_warn("error on deleting a probe.\n");

		warn++;

	}



	ret = traceprobe_command("-:testprobe2", create_trace_kprobe);

	ret = trace_run_command("-:testprobe2", create_trace_kprobe);

	if (WARN_ON_ONCE(ret)) {

		pr_warn("error on deleting a probe.\n");

		warn++;

kernel/trace/trace_probe.c

+0 −86
Original line number Diff line number Diff line
@@ -623,92 +623,6 @@ void traceprobe_free_probe_arg(struct probe_arg *arg) 
	kfree(arg->comm);

}



int traceprobe_command(const char *buf, int (*createfn)(int, char **))

{

	char **argv;

	int argc, ret;



	argc = 0;

	ret = 0;

	argv = argv_split(GFP_KERNEL, buf, &argc);

	if (!argv)

		return -ENOMEM;



	if (argc)

		ret = createfn(argc, argv);



	argv_free(argv);



	return ret;

}



#define WRITE_BUFSIZE  4096



ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,

				size_t count, loff_t *ppos,

				int (*createfn)(int, char **))

{

	char *kbuf, *buf, *tmp;

	int ret = 0;

	size_t done = 0;

	size_t size;



	kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);

	if (!kbuf)

		return -ENOMEM;



	while (done < count) {

		size = count - done;



		if (size >= WRITE_BUFSIZE)

			size = WRITE_BUFSIZE - 1;



		if (copy_from_user(kbuf, buffer + done, size)) {

			ret = -EFAULT;

			goto out;

		}

		kbuf[size] = '\0';

		buf = kbuf;

		do {

			tmp = strchr(buf, '\n');

			if (tmp) {

				*tmp = '\0';

				size = tmp - buf + 1;

			} else {

				size = strlen(buf);

				if (done + size < count) {

					if (buf != kbuf)

						break;

					/* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */

					pr_warn("Line length is too long: Should be less than %d\n",

						WRITE_BUFSIZE - 2);

					ret = -EINVAL;

					goto out;

				}

			}

			done += size;



			/* Remove comments */

			tmp = strchr(buf, '#');



			if (tmp)

				*tmp = '\0';



			ret = traceprobe_command(buf, createfn);

			if (ret)

				goto out;

			buf += size;



		} while (done < count);

	}

	ret = done;



out:

	kfree(kbuf);



	return ret;

}



static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,

			   bool is_return)

{

kernel/trace/trace_probe.h

+0 −7
Original line number Diff line number Diff line
@@ -42,7 +42,6 @@ 


#define MAX_TRACE_ARGS		128

#define MAX_ARGSTR_LEN		63

#define MAX_EVENT_NAME_LEN	64

#define MAX_STRING_SIZE		PATH_MAX



/* Reserved field names */
@@ -356,12 +355,6 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg); 


extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset);



extern ssize_t traceprobe_probes_write(struct file *file,

		const char __user *buffer, size_t count, loff_t *ppos,

		int (*createfn)(int, char**));



extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));



/* Sum up total data length for dynamic arraies (strings) */

static nokprobe_inline int

__get_data_size(struct trace_probe *tp, struct pt_regs *regs)

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