On Fri, 2019-11-08 at 21:34 +0100, Arnd Bergmann wrote:
The layout of struct timeval is different on sparc64 from anything else, and the patch I did long ago failed to take this into account.
Change it now to handle sparc64 user space correctly again.
Quite likely nobody cares about parallel ports on sparc64, but there is no reason not to fix it.
Cc: stable@vger.kernel.org Fixes: 9a450484089d ("lp: support 64-bit time_t user space") Signed-off-by: Arnd Bergmann arnd@arndb.de
drivers/char/lp.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/char/lp.c b/drivers/char/lp.c index 7c9269e3477a..bd95aba1f9fe 100644 --- a/drivers/char/lp.c +++ b/drivers/char/lp.c @@ -713,6 +713,10 @@ static int lp_set_timeout64(unsigned int minor, void __user *arg) if (copy_from_user(karg, arg, sizeof(karg))) return -EFAULT;
- /* sparc64 suseconds_t is 32-bit only */
- if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
karg[1] >>= 32;- return lp_set_timeout(minor, karg[0], karg[1]);
}
It seems like it would make way more sense to use __kernel_old_timeval. Then you don't have to explicitly handle the sparc64 oddity.
As it is, this still over-reads from user-space which might result in a spurious -EFAULT.
Ben.