Take an effort to recode the arm64 vdso code from assembler to C previously submitted by Andrew Pinski <[email protected]>, 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.
Add clock_getres vdso support to match up with existing support in the arm64's vdso. Signed-off-by: Mark Salyzyn <[email protected]> Cc: James Morse <[email protected]> Cc: Russell King <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: John Stultz <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Kees Cook <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Andy Gross <[email protected]> Cc: Kevin Brodsky <[email protected]> Cc: Andrew Pinski <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] v2: - split first CL into 7 of 7 pieces v4: - update commit message to reflect overall reasoning. - replace typeof() with long for nsec - replace clock_id with clock to match usage elsewhere. v5: - add linux/hrtimer.h to compiler.h to supply for LOW_RES_NSEC and MONOTONIC_RES_NSEC. --- arch/arm/kernel/vdso.c | 1 + arch/arm/vdso/compiler.h | 1 + arch/arm/vdso/vdso.lds.S | 1 + arch/arm/vdso/vgettimeofday.c | 23 +++++++++++++++++++++++ 4 files changed, 26 insertions(+) diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c index b7c93fce2f59..a80c58805699 100644 --- a/arch/arm/kernel/vdso.c +++ b/arch/arm/kernel/vdso.c @@ -189,6 +189,7 @@ static void __init patch_vdso(void *ehdr) if (!cntvct_ok) { vdso_nullpatch_one(&einfo, "__vdso_gettimeofday"); vdso_nullpatch_one(&einfo, "__vdso_clock_gettime"); + vdso_nullpatch_one(&einfo, "__vdso_clock_getres"); } } diff --git a/arch/arm/vdso/compiler.h b/arch/arm/vdso/compiler.h index 3edddb705a1b..c7751019246a 100644 --- a/arch/arm/vdso/compiler.h +++ b/arch/arm/vdso/compiler.h @@ -27,6 +27,7 @@ #include <asm/processor.h> /* for cpu_relax() */ #include <asm/unistd.h> #include <linux/compiler.h> +#include <linux/hrtimer.h> /* for LOW_RES_NSEC and MONOTONIC_RES_NSEC */ #include <linux/time.h> /* for NSEC_PER_SEC */ #ifndef CONFIG_AEABI diff --git a/arch/arm/vdso/vdso.lds.S b/arch/arm/vdso/vdso.lds.S index 89ca89f12d23..1d81e8c3acf6 100644 --- a/arch/arm/vdso/vdso.lds.S +++ b/arch/arm/vdso/vdso.lds.S @@ -82,6 +82,7 @@ VERSION global: __vdso_clock_gettime; __vdso_gettimeofday; + __vdso_clock_getres; local: *; }; } diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c index a2c4db83edc4..a354586f8a65 100644 --- a/arch/arm/vdso/vgettimeofday.c +++ b/arch/arm/vdso/vgettimeofday.c @@ -32,6 +32,7 @@ DEFINE_FALLBACK(gettimeofday, struct timeval *, tv, struct timezone *, tz) DEFINE_FALLBACK(clock_gettime, clockid_t, clock, struct timespec *, ts) +DEFINE_FALLBACK(clock_getres, clockid_t, clock, struct timespec *, ts) static notrace u32 vdso_read_begin(const struct vdso_data *vd) { @@ -301,3 +302,25 @@ notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) return 0; } + +int __vdso_clock_getres(clockid_t clock, struct timespec *res) +{ + long nsec; + + if (clock == CLOCK_REALTIME || + clock == CLOCK_MONOTONIC || + clock == CLOCK_MONOTONIC_RAW) + nsec = MONOTONIC_RES_NSEC; + else if (clock == CLOCK_REALTIME_COARSE || + clock == CLOCK_MONOTONIC_COARSE) + nsec = LOW_RES_NSEC; + else + return clock_getres_fallback(clock, res); + + if (likely(res != NULL)) { + res->tv_sec = 0; + res->tv_nsec = nsec; + } + + return 0; +} -- 2.15.0.403.gc27cc4dac6-goog
