efivarfs: Don't return -EINTR when rate-limiting reads
Applications that read EFI variables may see a return
value of -EINTR if they exceed the rate limit and a
signal delivery is attempted while the process is sleeping.
This is quite surprising to the application, which probably
doesn't have code to handle it.
Change the interruptible sleep to a non-interruptible one.
Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20200528194905.690-3-tony.luck@intel.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index 4b8bc45..feaa5e1 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -73,10 +73,8 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
ssize_t size = 0;
int err;
- while (!__ratelimit(&file->f_cred->user->ratelimit)) {
- if (!msleep_interruptible(50))
- return -EINTR;
- }
+ while (!__ratelimit(&file->f_cred->user->ratelimit))
+ msleep(50);
err = efivar_entry_size(var, &datasize);