profile: setup_profiling_timer() is moslty not implemented
The setup_profiling_timer() is mostly un-implemented by many
architectures. In many places it isn't guarded by CONFIG_PROFILE which is
needed for it to be used. Make it a weak symbol in kernel/profile.c and
remove the 'return -EINVAL' implementations from the kenrel.
There are a couple of architectures which do return 0 from the
setup_profiling_timer() function but they don't seem to do anything else
with it. To keep the /proc compatibility for now, leave these for a
future update or removal.
On ARM, this fixes the following sparse warning:
arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static?
Link: https://lkml.kernel.org/r/20220721195509.418205-1-ben-linux@fluff.org
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/kernel/profile.c b/kernel/profile.c
index ae82ddf..7ea01ba 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -425,6 +425,12 @@ read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos)
return read;
}
+/* default is to not implement this call */
+int __weak setup_profiling_timer(unsigned mult)
+{
+ return -EINVAL;
+}
+
/*
* Writing to /proc/profile resets the counters
*
@@ -435,8 +441,6 @@ static ssize_t write_profile(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
#ifdef CONFIG_SMP
- extern int setup_profiling_timer(unsigned int multiplier);
-
if (count == sizeof(int)) {
unsigned int multiplier;
