On 7/28/19 2:12 PM, Thomas Gleixner wrote: > 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. >
Reviewed-by: Vincenzo Frascino <[email protected]> Tested-by: Vincenzo Frascino <[email protected]> > Reported-by: Sean Christopherson <[email protected]> > Reported-by: Paul Bolle <[email protected]> > Suggested-by: Andy Lutomirski <[email protected]> > Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation") > Signed-off-by: Thomas Gleixner <[email protected]> > --- > Note: > > The NULL pointer check in the getres/getres32() fallbacks is just wrong. > The proper return code for a NULL pointer is -EFAULT. How did this ever > pass any posix test? Also it just should go away because any other invalid > pointer will be caught in the syscall anyway. The clockid check is also > part of the syscall so no point in having it here again. Handling calls > with invalid arguments is not really a performance critical operation. > > --- > arch/arm64/include/asm/vdso/compat_gettimeofday.h | 40 > ++++++++++++++++++++++ > 1 file changed, 40 insertions(+) > > --- a/arch/arm64/include/asm/vdso/compat_gettimeofday.h > +++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h > @@ -16,6 +16,8 @@ > > #define VDSO_HAS_CLOCK_GETRES 1 > > +#define VDSO_HAS_32BIT_FALLBACK 1 > + > static __always_inline > int gettimeofday_fallback(struct __kernel_old_timeval *_tv, > struct timezone *_tz) > @@ -52,6 +54,23 @@ long clock_gettime_fallback(clockid_t _c > } > > static __always_inline > +long clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts) > +{ > + register struct old_timespec32 *ts asm("r1") = _ts; > + register clockid_t clkid asm("r0") = _clkid; > + register long ret asm ("r0"); > + register long nr asm("r7") = __NR_compat_clock_gettime; > + > + asm volatile( > + " swi #0\n" > + : "=r" (ret) > + : "r" (clkid), "r" (ts), "r" (nr) > + : "memory"); > + > + return ret; > +} > + > +static __always_inline > int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) > { > register struct __kernel_timespec *ts asm("r1") = _ts; > @@ -61,6 +80,27 @@ int clock_getres_fallback(clockid_t _clk > > /* The checks below are required for ABI consistency with arm */ > if ((_clkid >= MAX_CLOCKS) && (_ts == NULL)) > + return -EINVAL; > + > + asm volatile( > + " swi #0\n" > + : "=r" (ret) > + : "r" (clkid), "r" (ts), "r" (nr) > + : "memory"); > + > + return ret; > +} > + > +static __always_inline > +int clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts) > +{ > + register struct old_timespec32 *ts asm("r1") = _ts; > + register clockid_t clkid asm("r0") = _clkid; > + register long ret asm ("r0"); > + register long nr asm("r7") = __NR_compat_clock_getres; > + > + /* The checks below are required for ABI consistency with arm */ > + if ((_clkid >= MAX_CLOCKS) && (_ts == NULL)) > return -EINVAL; > > asm volatile( > > -- Regards, Vincenzo
