x86/entry/64/compat: Fix bad fast syscall arg failure path

If user code does SYSCALL32 or SYSENTER without a valid stack,
then our attempt to determine the syscall args will result in a
failed uaccess fault.  Previously, we would try to recover by
jumping to the syscall exit code, but we'd run the syscall exit
work even though we never made it to the syscall entry work.

Clean it up by treating the failure path as a non-syscall entry
and exit pair.

This fixes strace's output when running the syscall_arg_fault
test. Without this fix, strace would get out of sync and would
fail to associate syscall entries with syscall exits.

Signed-off-by: Andy Lutomirski <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/903010762c07a3d67df914fea2da84b52b0f8f1d.1435952415.git.luto@kernel.org
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions