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>
This commit is contained in:
Tony Luck 2020-05-28 12:49:05 -07:00 committed by Ard Biesheuvel
parent 2096721f15
commit 4353f03317

View File

@ -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);