On Mon, Feb 10, 2025 at 10:41:00AM +0100, Alice Ryhl wrote:

On Sat, Feb 8, 2025 at 4:01 AM FUJITA Tomonori
[off-list ref] wrote:

quoted

On Fri, 7 Feb 2025 18:12:58 +0000
David Laight [off-list ref] wrote:

quoted

quoted

 static void print_preempt_disable_ip(int preempt_offset, unsigned long ip)
 {
     if (!IS_ENABLED(CONFIG_DEBUG_PREEMPT))

@@ -8717,7 +8699,8 @@ static inline bool resched_offsets_ok(unsigned int offsets)
     return nested == offsets;
 }

-void __might_resched(const char *file, int line, unsigned int offsets)
+static void __might_resched_precision(const char *file, int len, int line,

For clarity that ought to be file_len.

Yeah, I'll update.

quoted

quoted

+                                  unsigned int offsets)
 {
     /* Ratelimiting timestamp: */
     static unsigned long prev_jiffy;

@@ -8740,8 +8723,10 @@ void __might_resched(const char *file, int line, unsigned int offsets)
     /* Save this before calling printk(), since that will clobber it: */
     preempt_disable_ip = get_preempt_disable_ip(current);

-    pr_err("BUG: sleeping function called from invalid context at %s:%d\n",
-           file, line);
+    if (len < 0)
+            len = strlen(file);

No need for strlen(), just use a big number instead of -1.
Anything bigger than a sane upper limit on the filename length will do.

Ah, that's right. Just passing the maximum precision (1<<15-1) works.

The precision specifies the maximum length. vsnprintf() always
iterates through a string until it reaches the maximum length or
encounters the null terminator. So strlen() here is useless.

Alice and Boqun, the above change is fine? Can I keep the tags?

I'd probably like a comment explaining the meaning of this constant
somewhere, but sure ok with me.

Agreed. The code should be fine but need some comments.

Regards,
Boqun

Alice