Messages in this thread Patch in this message | | | From | Mark Salyzyn <> | Subject | RESEND [PATCH v5 12/12] lib: vdso: do not expose gettimeofday, if no arch supported timer | Date | Mon, 1 Oct 2018 10:58:32 -0700 |
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Take an effort to recode the arm64 vdso code from assembler to C previously submitted by Andrew Pinski <apinski@cavium.com>, rework it for use in both arm and arm64, overlapping any optimizations for each architecture. But instead of landing it in arm64, land the result into lib/vdso and unify both implementations to simplify future maintenance.
If ARCH_PROVIDES_TIMER is not defined, do not expose gettimeofday. libc will default directly to syscall. Also ifdef clock_gettime switch cases and stubs if not supported and other unused components.
Signed-off-by: Mark Salyzyn <salyzyn@android.com> Tested-by: Mark Salyzyn <salyzyn@android.com> Cc: James Morse <james.morse@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Gross <andy.gross@linaro.org> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Andrew Pinski <apinski@cavium.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: Jeremy Linton <Jeremy.Linton@arm.com> Cc: android-kernel@android.com
v3: - do not expose gettimeofday if arch does not support user space timer.
v4: - update commit message to reflect overall reasoning of patch series.
v5: - rebase --- lib/vdso/vgettimeofday.c | 52 ++++++++++++++++------------------------ 1 file changed, 20 insertions(+), 32 deletions(-)
diff --git a/lib/vdso/vgettimeofday.c b/lib/vdso/vgettimeofday.c index 4c3af7bc6499..54e519c99c4b 100644 --- a/lib/vdso/vgettimeofday.c +++ b/lib/vdso/vgettimeofday.c @@ -30,7 +30,9 @@ #include "compiler.h" #include "datapage.h" +#ifdef ARCH_PROVIDES_TIMER DEFINE_FALLBACK(gettimeofday, struct timeval *, tv, struct timezone *, tz) +#endif DEFINE_FALLBACK(clock_gettime, clockid_t, clock, struct timespec *, ts) DEFINE_FALLBACK(clock_getres, clockid_t, clock, struct timespec *, ts) @@ -292,30 +294,6 @@ static notrace int do_boottime(const struct vdso_data *vd, struct timespec *ts) return 0; } -#else /* ARCH_PROVIDES_TIMER */ - -static notrace int do_realtime(const struct vdso_data *vd, struct timespec *ts) -{ - return -1; -} - -static notrace int do_monotonic(const struct vdso_data *vd, struct timespec *ts) -{ - return -1; -} - -static notrace int do_monotonic_raw(const struct vdso_data *vd, - struct timespec *ts) -{ - return -1; -} - -static notrace int do_boottime(const struct vdso_data *vd, - struct timespec *ts) -{ - return -1; -} - #endif /* ARCH_PROVIDES_TIMER */ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) @@ -329,6 +307,7 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) case CLOCK_MONOTONIC_COARSE: do_monotonic_coarse(vd, ts); break; +#ifdef ARCH_PROVIDES_TIMER case CLOCK_REALTIME: if (do_realtime(vd, ts)) goto fallback; @@ -345,6 +324,7 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) if (do_boottime(vd, ts)) goto fallback; break; +#endif default: goto fallback; } @@ -354,6 +334,7 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) return clock_gettime_fallback(clock, ts); } +#ifdef ARCH_PROVIDES_TIMER notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) { const struct vdso_data *vd = __get_datapage(); @@ -375,21 +356,28 @@ notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) return 0; } +#endif int __vdso_clock_getres(clockid_t clock, struct timespec *res) { long nsec; - if (clock == CLOCK_REALTIME || - clock == CLOCK_BOOTTIME || - clock == CLOCK_MONOTONIC || - clock == CLOCK_MONOTONIC_RAW) - nsec = MONOTONIC_RES_NSEC; - else if (clock == CLOCK_REALTIME_COARSE || - clock == CLOCK_MONOTONIC_COARSE) + switch (clock) { + case CLOCK_REALTIME_COARSE: + case CLOCK_MONOTONIC_COARSE: nsec = LOW_RES_NSEC; - else + break; +#ifdef ARCH_PROVIDES_TIMER + case CLOCK_REALTIME: + case CLOCK_MONOTONIC: + case CLOCK_MONOTONIC_RAW: + case CLOCK_BOOTTIME: + nsec = MONOTONIC_RES_NSEC; + break; +#endif + default: return clock_getres_fallback(clock, res); + } if (likely(res != NULL)) { res->tv_sec = 0; -- 2.19.0.605.g01d371f741-goog
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