From 4c5a116ada953b86125ab7c70a57c57463a55a55 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 4 Aug 2020 22:37:48 +0200 Subject: [PATCH] vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter() MIPS already uses and S390 will need the vdso data pointer in __arch_get_hw_counter(). This works nicely as long as the architecture does not support time namespaces in the VDSO. With time namespaces enabled the regular accessor to the vdso data pointer __arch_get_vdso_data() will return the namespace specific VDSO data page for tasks which are part of a non-root time namespace. This would cause the architectures which need the vdso data pointer in __arch_get_hw_counter() to access the wrong vdso data page. Add a vdso_data pointer argument to __arch_get_hw_counter() and hand it in from the call sites in the core code. For architectures which do not need the data pointer in their counter accessor function the compiler will just optimize it out. Fix up all existing architecture implementations and make MIPS utilize the pointer instead of invoking the accessor function. No functional change and no change in the resulting object code (except MIPS). Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/draft-87wo2ekuzn.fsf@nanos.tec.linutronix.de --- arch/arm/include/asm/vdso/gettimeofday.h | 3 ++- arch/arm64/include/asm/vdso/compat_gettimeofday.h | 3 ++- arch/arm64/include/asm/vdso/gettimeofday.h | 3 ++- arch/mips/include/asm/vdso/gettimeofday.h | 5 +++-- arch/riscv/include/asm/vdso/gettimeofday.h | 3 ++- arch/x86/include/asm/vdso/gettimeofday.h | 3 ++- lib/vdso/gettimeofday.c | 4 ++-- 7 files changed, 15 insertions(+), 9 deletions(-) diff --git a/arch/arm/include/asm/vdso/gettimeofday.h b/arch/arm/include/asm/vdso/gettimeofday.h index 1b207cf07697..2134cbd5469f 100644 --- a/arch/arm/include/asm/vdso/gettimeofday.h +++ b/arch/arm/include/asm/vdso/gettimeofday.h @@ -113,7 +113,8 @@ static inline bool arm_vdso_hres_capable(void) } #define __arch_vdso_hres_capable arm_vdso_hres_capable -static __always_inline u64 __arch_get_hw_counter(int clock_mode) +static __always_inline u64 __arch_get_hw_counter(int clock_mode, + const struct vdso_data *vd) { #ifdef CONFIG_ARM_ARCH_TIMER u64 cycle_now; diff --git a/arch/arm64/include/asm/vdso/compat_gettimeofday.h b/arch/arm64/include/asm/vdso/compat_gettimeofday.h index 75cbae60455b..7508b0ac1d21 100644 --- a/arch/arm64/include/asm/vdso/compat_gettimeofday.h +++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h @@ -103,7 +103,8 @@ int clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts) return ret; } -static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) +static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, + const struct vdso_data *vd) { u64 res; diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h index 9c29ad3049f8..631ab1281633 100644 --- a/arch/arm64/include/asm/vdso/gettimeofday.h +++ b/arch/arm64/include/asm/vdso/gettimeofday.h @@ -64,7 +64,8 @@ int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) return ret; } -static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) +static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, + const struct vdso_data *vd) { u64 res; diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h index c63ddcaea54c..2203e2d0ae2a 100644 --- a/arch/mips/include/asm/vdso/gettimeofday.h +++ b/arch/mips/include/asm/vdso/gettimeofday.h @@ -167,7 +167,8 @@ static __always_inline u64 read_gic_count(const struct vdso_data *data) #endif -static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) +static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, + const struct vdso_data *vd) { #ifdef CONFIG_CSRC_R4K if (clock_mode == VDSO_CLOCKMODE_R4K) @@ -175,7 +176,7 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) #endif #ifdef CONFIG_CLKSRC_MIPS_GIC if (clock_mode == VDSO_CLOCKMODE_GIC) - return read_gic_count(get_vdso_data()); + return read_gic_count(vd); #endif /* * Core checks mode already. So this raced against a concurrent diff --git a/arch/riscv/include/asm/vdso/gettimeofday.h b/arch/riscv/include/asm/vdso/gettimeofday.h index 3099362d9f26..f839f16e0d2a 100644 --- a/arch/riscv/include/asm/vdso/gettimeofday.h +++ b/arch/riscv/include/asm/vdso/gettimeofday.h @@ -60,7 +60,8 @@ int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) return ret; } -static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) +static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, + const struct vdso_data *vd) { /* * The purpose of csr_read(CSR_TIME) is to trap the system into diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h index fb81fea99093..df01d7349d79 100644 --- a/arch/x86/include/asm/vdso/gettimeofday.h +++ b/arch/x86/include/asm/vdso/gettimeofday.h @@ -241,7 +241,8 @@ static u64 vread_hvclock(void) } #endif -static inline u64 __arch_get_hw_counter(s32 clock_mode) +static inline u64 __arch_get_hw_counter(s32 clock_mode, + const struct vdso_data *vd) { if (likely(clock_mode == VDSO_CLOCKMODE_TSC)) return (u64)rdtsc_ordered(); diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index bcc9a98a0524..2919f1698140 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -68,7 +68,7 @@ static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk, if (unlikely(!vdso_clocksource_ok(vd))) return -1; - cycles = __arch_get_hw_counter(vd->clock_mode); + cycles = __arch_get_hw_counter(vd->clock_mode, vd); if (unlikely(!vdso_cycles_ok(cycles))) return -1; ns = vdso_ts->nsec; @@ -138,7 +138,7 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk, if (unlikely(!vdso_clocksource_ok(vd))) return -1; - cycles = __arch_get_hw_counter(vd->clock_mode); + cycles = __arch_get_hw_counter(vd->clock_mode, vd); if (unlikely(!vdso_cycles_ok(cycles))) return -1; ns = vdso_ts->nsec;