x86/vdso/32: Use 32bit syscall fallback
authorThomas Gleixner <tglx@linutronix.de>
Sun, 28 Jul 2019 13:12:55 +0000 (15:12 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Tue, 30 Jul 2019 22:09:10 +0000 (00:09 +0200)
commitd2f5d3fa26196183adb44a413c44caa9872275b4
tree626f069300d13e15ccd8f835124cb17e68d113df
parentc60a32ea4f459f99b98d383cad3b1ac7cfb3f4be
x86/vdso/32: Use 32bit syscall fallback

The generic VDSO implementation uses the Y2038 safe clock_gettime64() and
clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks
seccomp setups because these syscalls might be not (yet) allowed.

Implement the 32bit variants which use the legacy syscalls and select the
variant in the core library.

The 64bit time variants are not removed because they are required for the
time64 based vdso accessors.

Fixes: 7ac870747988 ("x86/vdso: Switch to generic vDSO implementation")
Reported-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reported-by: Paul Bolle <pebolle@tiscali.nl>
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20190728131648.879156507@linutronix.de
arch/x86/include/asm/vdso/gettimeofday.h