On 7/28/19 2:12 PM, Thomas Gleixner wrote: > To allow syscall fallbacks using the legacy 32bit syscall for 32bit VDSO > builds, move the fallback invocation out into the callers. > > Split the common code out of __cvdso_clock_gettime/getres() and invoke the > syscall fallback in the 64bit and 32bit variants. > > Preparatory work for using legacy syscalls in 32bit VDSO. No functional > change. >
Reviewed-by: Vincenzo Frascino <[email protected]> Tested-by: Vincenzo Frascino <[email protected]> > Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation") > Signed-off-by: Thomas Gleixner <[email protected]> > --- > lib/vdso/gettimeofday.c | 53 > ++++++++++++++++++++++++++++++++---------------- > 1 file changed, 36 insertions(+), 17 deletions(-) > > --- a/lib/vdso/gettimeofday.c > +++ b/lib/vdso/gettimeofday.c > @@ -51,7 +51,7 @@ static int do_hres(const struct vdso_dat > ns = vdso_ts->nsec; > last = vd->cycle_last; > if (unlikely((s64)cycles < 0)) > - return clock_gettime_fallback(clk, ts); > + return -1; > > ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult); > ns >>= vd->shift; > @@ -82,14 +82,14 @@ static void do_coarse(const struct vdso_ > } > > static __maybe_unused int > -__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) > +__cvdso_clock_gettime_common(clockid_t clock, struct __kernel_timespec *ts) > { > const struct vdso_data *vd = __arch_get_vdso_data(); > u32 msk; > > /* Check for negative values or invalid clocks */ > if (unlikely((u32) clock >= MAX_CLOCKS)) > - goto fallback; > + return -1; > > /* > * Convert the clockid to a bitmask and use it to check which > @@ -104,9 +104,17 @@ static __maybe_unused int > } else if (msk & VDSO_RAW) { > return do_hres(&vd[CS_RAW], clock, ts); > } > + return -1; > +} > > -fallback: > - return clock_gettime_fallback(clock, ts); > +static __maybe_unused int > +__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) > +{ > + int ret = __cvdso_clock_gettime_common(clock, ts); > + > + if (unlikely(ret)) > + return clock_gettime_fallback(clock, ts); > + return 0; > } > > static __maybe_unused int > @@ -115,9 +123,12 @@ static __maybe_unused int > struct __kernel_timespec ts; > int ret; > > - ret = __cvdso_clock_gettime(clock, &ts); > + ret = __cvdso_clock_gettime_common(clock, &ts); > > - if (ret == 0) { > + if (unlikely(ret)) > + ret = clock_gettime_fallback(clock, &ts); > + > + if (likely(!ret)) { > res->tv_sec = ts.tv_sec; > res->tv_nsec = ts.tv_nsec; > } > @@ -163,17 +174,18 @@ static __maybe_unused time_t __cvdso_tim > > #ifdef VDSO_HAS_CLOCK_GETRES > static __maybe_unused > -int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res) > +int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec > *res) > { > const struct vdso_data *vd = __arch_get_vdso_data(); > - u64 ns; > + u64 hrtimer_res; > u32 msk; > - u64 hrtimer_res = READ_ONCE(vd[CS_HRES_COARSE].hrtimer_res); > + u64 ns; > > /* Check for negative values or invalid clocks */ > if (unlikely((u32) clock >= MAX_CLOCKS)) > - goto fallback; > + return -1; > > + hrtimer_res = READ_ONCE(vd[CS_HRES_COARSE].hrtimer_res); > /* > * Convert the clockid to a bitmask and use it to check which > * clocks are handled in the VDSO directly. > @@ -195,16 +207,22 @@ int __cvdso_clock_getres(clockid_t clock > */ > ns = hrtimer_res; > } else { > - goto fallback; > + return -1; > } > > res->tv_sec = 0; > res->tv_nsec = ns; > > return 0; > +} > + > +int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res) > +{ > + int ret = __cvdso_clock_getres_common(clock, res); > > -fallback: > - return clock_getres_fallback(clock, res); > + if (unlikely(ret)) > + return clock_getres_fallback(clock, res); > + return 0; > } > > static __maybe_unused int > @@ -213,13 +231,14 @@ static __maybe_unused int > struct __kernel_timespec ts; > int ret; > > - ret = __cvdso_clock_getres(clock, &ts); > + ret = __cvdso_clock_getres_common(clock, &ts); > + if (unlikely(ret)) > + ret = clock_getres_fallback(clock, &ts); > > - if (ret == 0) { > + if (likely(!ret)) { > res->tv_sec = ts.tv_sec; > res->tv_nsec = ts.tv_nsec; > } > - > return ret; > } > #endif /* VDSO_HAS_CLOCK_GETRES */ > > -- Regards, Vincenzo
