[RFC][PATCH 08/21] tracing: Make traceprobe parsing code reusable

Tom Zanussi
2017-02-08T17:28:52Z

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().

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
---
kernel/trace/trace.c | 75 +++++++++++++++++++++++++++++++++++++++++++++
kernel/trace/trace.h | 7 +++++
kernel/trace/trace_kprobe.c | 18 +++++------
kernel/trace/trace_probe.c | 75 ---------------------------------------------
kernel/trace/trace_probe.h | 7 -----
kernel/trace/trace_uprobe.c | 2 +-
6 files changed, 92 insertions(+), 92 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5868656..78dff2f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7912,6 +7912,81 @@ 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, *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';
+ tmp = strchr(kbuf, '\n');
+
+ if (tmp) {
+ *tmp = '\0';
+ size = tmp - kbuf + 1;
+ } else if (done + size < count) {
+ pr_warn("Line length is too long: Should be less than %d\n",
+ WRITE_BUFSIZE);
+ ret = -EINVAL;
+ goto out;
+ }
+ done += size;
+ /* Remove comments */
+ tmp = strchr(kbuf, '#');
+
+ if (tmp)
+ *tmp = '\0';
+
+ ret = trace_run_command(kbuf, createfn);
+ if (ret)
+ goto out;
+ }
+ ret = done;
+
+out:
+ kfree(kbuf);
+
+ return ret;
+}
+
__init static int tracer_alloc_buffers(void)
{
int ring_buf_size;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index ac55fa1..f2af21b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1647,6 +1647,13 @@ extern int trace_event_enable_disable(struct trace_event_file *file,
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
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index a133ecd..8f3b4d9 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -876,8 +876,8 @@ 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,
- create_trace_kprobe);
+ return trace_parse_run_command(file, buffer, count, ppos,
+ create_trace_kprobe);
}

static const struct file_operations kprobe_events_ops = {
@@ -1402,9 +1402,9 @@ static __init int kprobe_trace_self_tests_init(void)

pr_info("Testing kprobe tracing: ");

- ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "
- "$stack $stack0 +0($stack)",
- create_trace_kprobe);
+ ret = trace_run_command("p:testprobe kprobe_trace_selftest_target "
+ "$stack $stack0 +0($stack)",
+ create_trace_kprobe);
if (WARN_ON_ONCE(ret)) {
pr_warn("error on probing function entry.\n");
warn++;
@@ -1424,8 +1424,8 @@ static __init int kprobe_trace_self_tests_init(void)
}
}

- ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
- "$retval", create_trace_kprobe);
+ ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target "
+ "$retval", create_trace_kprobe);
if (WARN_ON_ONCE(ret)) {
pr_warn("error on probing function return.\n");
warn++;
@@ -1495,13 +1495,13 @@ 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++;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 8c0553d..b7de026 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -622,81 +622,6 @@ 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, *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';
- tmp = strchr(kbuf, '\n');
-
- if (tmp) {
- *tmp = '\0';
- size = tmp - kbuf + 1;
- } else if (done + size < count) {
- pr_warn("Line length is too long: Should be less than %d\n",
- WRITE_BUFSIZE);
- ret = -EINVAL;
- goto out;
- }
- done += size;
- /* Remove comments */
- tmp = strchr(kbuf, '#');
-
- if (tmp)
- *tmp = '\0';
-
- ret = traceprobe_command(kbuf, createfn);
- if (ret)
- goto out;
- }
- ret = done;
-
-out:
- kfree(kbuf);
-
- return ret;
-}
-
static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
bool is_return)
{
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 0c0ae54..37ab38c 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -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 int traceprobe_conflict_field_name(const char *name,

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)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 4f2ba2b..10e3ec8 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -649,7 +649,7 @@ 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, create_trace_uprobe);
+ return trace_parse_run_command(file, buffer, count, ppos, create_trace_uprobe);
}

static const struct file_operations uprobe_events_ops = {
--
1.9.3