Implement ->proc_write_buf() so procfs copies in what is written before
it pins the entry, and parse the option from that copy. Writes larger
than PAGE_SIZE - 1 bytes fail with -EINVAL now.
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
drivers/macintosh/via-pmu.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/macintosh/via-pmu.c b/drivers/macintosh/via-pmu.c
index 49f929ae10e4..079c085be5d2 100644
--- a/drivers/macintosh/via-pmu.c
+++ b/drivers/macintosh/via-pmu.c
@@ -913,7 +913,7 @@ static int pmu_options_proc_show(struct seq_file *m, void *v)
}
static ssize_t pmu_options_proc_write(struct file *file,
- const char __user *buffer, size_t count, loff_t *pos)
+ char *buffer, size_t count, loff_t *pos)
{
char tmp[33];
char *label, *val;@@ -923,8 +923,7 @@ static ssize_t pmu_options_proc_write(struct file *file,
return -EINVAL;
if (count > 32)
count = 32;
- if (copy_from_user(tmp, buffer, count))
- return -EFAULT;
+ memcpy(tmp, buffer, count);
tmp[count] = 0;
label = tmp;
@@ -958,7 +957,7 @@ static ssize_t pmu_options_proc_write(struct file *file,
static const struct proc_ops pmu_options_proc_ops = {
.proc_show = pmu_options_proc_show,
- .proc_write = pmu_options_proc_write,
+ .proc_write_buf = pmu_options_proc_write,
};
#endif
--
2.53.0