diff options
| author | Tomas Glozar <tglozar@redhat.com> | 2025-04-25 11:18:39 +0200 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2025-05-08 09:36:09 -0400 |
| commit | 17f89102fe23d7389085a8820550df688f79888a (patch) | |
| tree | ff10ff4c59bbd0b32361c74e05a33f4bc4dc31da | |
| parent | a54665ab7c20081cb6299d79dcab9960752bc741 (diff) | |
tracing/osnoise: Allow arbitrarily long CPU string
Allocate kernel memory for processing CPU string
(/sys/kernel/tracing/osnoise/cpus) also in osnoise_cpus_write to allow
the writing of a CPU string of an arbitrary length.
This replaces the 256-byte buffer, which is insufficient with the rising
number of CPUs. For example, if I wanted to measure on every even CPU
on a system with 256 CPUs, the string would be 456 characters long.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250425091839.343289-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace_osnoise.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index e732c9e37e14..6819b93309ce 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -2302,7 +2302,7 @@ osnoise_cpus_read(struct file *filp, char __user *ubuf, size_t count, * osnoise_cpus_write - Write function for "cpus" entry * @filp: The active open file structure * @ubuf: The user buffer that contains the value to write - * @cnt: The maximum number of bytes to write to "file" + * @count: The maximum number of bytes to write to "file" * @ppos: The current position in @file * * This function provides a write implementation for the "cpus" @@ -2320,10 +2320,11 @@ osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count, { cpumask_var_t osnoise_cpumask_new; int running, err; - char buf[256]; + char *buf __free(kfree) = NULL; - if (count >= 256) - return -EINVAL; + buf = kmalloc(count, GFP_KERNEL); + if (!buf) + return -ENOMEM; if (copy_from_user(buf, ubuf, count)) return -EFAULT; |