From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932723AbdJaSdv (ORCPT ); Tue, 31 Oct 2017 14:33:51 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:43340 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932628AbdJaSdt (ORCPT ); Tue, 31 Oct 2017 14:33:49 -0400 X-Google-Smtp-Source: ABhQp+T5cudonyqcT2SEUxrl7VnCr7cYSSGPf5RLsl+/m7nvnhrx4JI2Nn2u8Zwyhr0mHgvPNSS2ig== From: Mark Salyzyn To: linux-kernel@vger.kernel.org Cc: Mark Salyzyn , James Morse , Russell King , Catalin Marinas , Will Deacon , Andy Lutomirski , Dmitry Safonov , John Stultz , Mark Rutland , Laura Abbott , Kees Cook , Ard Biesheuvel , Andy Gross , Kevin Brodsky , Andrew Pinski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 12/12] lib: vdso: do not expose gettimeofday, if no arch supported timer Date: Tue, 31 Oct 2017 11:33:40 -0700 Message-Id: <20171031183345.81499-1-salyzyn@android.com> X-Mailer: git-send-email 2.15.0.rc2.357.g7e34df9404-goog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Take an effort to recode the arm64 vdso code from assembler to C previously submitted by Andrew Pinski , 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 Cc: James Morse Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Andy Lutomirski Cc: Dmitry Safonov Cc: John Stultz Cc: Mark Rutland Cc: Laura Abbott Cc: Kees Cook Cc: Ard Biesheuvel Cc: Andy Gross Cc: Kevin Brodsky Cc: Andrew Pinski Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org v3: - do not expose gettimeofday if arch does not support user space timer. v4: - update commit message to reflect overall reasoning of patch series. --- 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 4f500aba7e60..896e20e34a23 100644 --- a/lib/vdso/vgettimeofday.c +++ b/lib/vdso/vgettimeofday.c @@ -29,7 +29,9 @@ #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) @@ -285,30 +287,6 @@ 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) @@ -322,6 +300,7 @@ 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; @@ -338,6 +317,7 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts) if (do_boottime(vd, ts)) goto fallback; break; +#endif default: goto fallback; } @@ -347,6 +327,7 @@ 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(); @@ -368,21 +349,28 @@ 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; -- 2.15.0.rc2.357.g7e34df9404-goog