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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-10 11:48:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-10 11:48:37 -0800
commit404dbad38248fc07b721f4201318418ce94fcb02 (patch)
treebec5e58d0f9828750afd948a0b4e42c6d279a283
parentff8be964208e6b6f1341f0645857c67830a78379 (diff)
parenta5d05b07961a2df47d3b4aae3bdae61ac095a43c (diff)
Merge tag 'pstore-v5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull pstore update from Kees Cook: - Add boot param for early ftrace recording in pstore (Uwe Kleine-König) * tag 'pstore-v5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: pstore/ftrace: Allow immediate recording
-rw-r--r--fs/pstore/ftrace.c46
1 files changed, 30 insertions, 16 deletions
diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c
index 5939595f0115..776cae20af4e 100644
--- a/fs/pstore/ftrace.c
+++ b/fs/pstore/ftrace.c
@@ -64,20 +64,12 @@ static struct ftrace_ops pstore_ftrace_ops __read_mostly = {
static DEFINE_MUTEX(pstore_ftrace_lock);
static bool pstore_ftrace_enabled;
-static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
- size_t count, loff_t *ppos)
+static int pstore_set_ftrace_enabled(bool on)
{
- u8 on;
ssize_t ret;
- ret = kstrtou8_from_user(buf, count, 2, &on);
- if (ret)
- return ret;
-
- mutex_lock(&pstore_ftrace_lock);
-
- if (!on ^ pstore_ftrace_enabled)
- goto out;
+ if (on == pstore_ftrace_enabled)
+ return 0;
if (on) {
ftrace_ops_set_global_filter(&pstore_ftrace_ops);
@@ -89,15 +81,30 @@ static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
if (ret) {
pr_err("%s: unable to %sregister ftrace ops: %zd\n",
__func__, on ? "" : "un", ret);
- goto err;
+ } else {
+ pstore_ftrace_enabled = on;
}
- pstore_ftrace_enabled = on;
-out:
- ret = count;
-err:
+ return ret;
+}
+
+static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ u8 on;
+ ssize_t ret;
+
+ ret = kstrtou8_from_user(buf, count, 2, &on);
+ if (ret)
+ return ret;
+
+ mutex_lock(&pstore_ftrace_lock);
+ ret = pstore_set_ftrace_enabled(on);
mutex_unlock(&pstore_ftrace_lock);
+ if (ret == 0)
+ ret = count;
+
return ret;
}
@@ -117,6 +124,11 @@ static const struct file_operations pstore_knob_fops = {
static struct dentry *pstore_ftrace_dir;
+static bool record_ftrace;
+module_param(record_ftrace, bool, 0400);
+MODULE_PARM_DESC(record_ftrace,
+ "enable ftrace recording immediately (default: off)");
+
void pstore_register_ftrace(void)
{
if (!psinfo->write)
@@ -124,6 +136,8 @@ void pstore_register_ftrace(void)
pstore_ftrace_dir = debugfs_create_dir("pstore", NULL);
+ pstore_set_ftrace_enabled(record_ftrace);
+
debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir, NULL,
&pstore_knob_fops);
}