On 28/07/2019 14:12, 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]> > Reported-by: Sean Christopherson <[email protected]> > Reported-by: Paul Bolle <[email protected]> > Suggested-by: Andy Lutomirski <[email protected]> > Fixes: 7ac870747988 ("x86/vdso: Switch to generic vDSO implementation") > Signed-off-by: Thomas Gleixner <[email protected]> > --- > arch/x86/include/asm/vdso/gettimeofday.h | 36 > +++++++++++++++++++++++++++++++ > 1 file changed, 36 insertions(+) > > --- a/arch/x86/include/asm/vdso/gettimeofday.h > +++ b/arch/x86/include/asm/vdso/gettimeofday.h > @@ -96,6 +96,8 @@ long clock_getres_fallback(clockid_t _cl > > #else > > +#define VDSO_HAS_32BIT_FALLBACK 1 > + > static __always_inline > long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) > { > @@ -114,6 +116,23 @@ long clock_gettime_fallback(clockid_t _c > } > > static __always_inline > +long clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts) > +{ > + long ret; > + > + asm ( > + "mov %%ebx, %%edx \n" > + "mov %[clock], %%ebx \n" > + "call __kernel_vsyscall \n" > + "mov %%edx, %%ebx \n" > + : "=a" (ret), "=m" (*_ts) > + : "0" (__NR_clock_gettime), [clock] "g" (_clkid), "c" (_ts) > + : "edx"); > + > + return ret; > +} > + > +static __always_inline > long gettimeofday_fallback(struct __kernel_old_timeval *_tv, > struct timezone *_tz) > { > @@ -146,6 +165,23 @@ clock_getres_fallback(clockid_t _clkid, > : "edx"); > > return ret; > +} > + > +static __always_inline > +long clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts) > +{ > + long ret; > + > + asm ( > + "mov %%ebx, %%edx \n" > + "mov %[clock], %%ebx \n" > + "call __kernel_vsyscall \n" > + "mov %%edx, %%ebx \n" > + : "=a" (ret), "=m" (*_ts) > + : "0" (__NR_clock_getres), [clock] "g" (_clkid), "c" (_ts) > + : "edx"); > + > + return ret; > } > > #endif > > -- Regards, Vincenzo
