diff options
Diffstat (limited to 'arch/x86/vdso')
| -rw-r--r-- | arch/x86/vdso/Makefile | 17 | ||||
| -rw-r--r-- | arch/x86/vdso/vclock_gettime.c | 74 | ||||
| -rw-r--r-- | arch/x86/vdso/vdso.lds.S | 9 | ||||
| -rw-r--r-- | arch/x86/vdso/vextern.h | 16 | ||||
| -rw-r--r-- | arch/x86/vdso/vgetcpu.c | 3 | ||||
| -rw-r--r-- | arch/x86/vdso/vma.c | 27 | ||||
| -rw-r--r-- | arch/x86/vdso/vvar.c | 12 |
7 files changed, 71 insertions, 87 deletions
diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index b6552b189bcd..bef0bc962400 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -11,7 +11,7 @@ vdso-install-$(VDSO32-y) += $(vdso32-images) # files to link into the vdso -vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vvar.o +vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o # files to link into kernel obj-$(VDSO64-y) += vma.o vdso.o @@ -37,11 +37,24 @@ $(obj)/%.so: OBJCOPYFLAGS := -S $(obj)/%.so: $(obj)/%.so.dbg FORCE $(call if_changed,objcopy) +# +# Don't omit frame pointers for ease of userspace debugging, but do +# optimize sibling calls. +# CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ - $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) + $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \ + -fno-omit-frame-pointer -foptimize-sibling-calls $(vobjs): KBUILD_CFLAGS += $(CFL) +# +# vDSO code runs in userspace and -pg doesn't help with profiling anyway. +# +CFLAGS_REMOVE_vdso-note.o = -pg +CFLAGS_REMOVE_vclock_gettime.o = -pg +CFLAGS_REMOVE_vgetcpu.o = -pg +CFLAGS_REMOVE_vvar.o = -pg + targets += vdso-syms.lds obj-$(VDSO64-y) += vdso-syms.lds diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index ee55754cc3c5..a724905fdae7 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -2,7 +2,7 @@ * Copyright 2006 Andi Kleen, SUSE Labs. * Subject to the GNU Public License, v.2 * - * Fast user context implementation of clock_gettime and gettimeofday. + * Fast user context implementation of clock_gettime, gettimeofday, and time. * * The code should have no internal unresolved relocations. * Check with readelf after changing. @@ -22,9 +22,8 @@ #include <asm/hpet.h> #include <asm/unistd.h> #include <asm/io.h> -#include "vextern.h" -#define gtod vdso_vsyscall_gtod_data +#define gtod (&VVAR(vsyscall_gtod_data)) notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) { @@ -56,22 +55,6 @@ notrace static noinline int do_realtime(struct timespec *ts) return 0; } -/* Copy of the version in kernel/time.c which we cannot directly access */ -notrace static void -vset_normalized_timespec(struct timespec *ts, long sec, long nsec) -{ - while (nsec >= NSEC_PER_SEC) { - nsec -= NSEC_PER_SEC; - ++sec; - } - while (nsec < 0) { - nsec += NSEC_PER_SEC; - --sec; - } - ts->tv_sec = sec; - ts->tv_nsec = nsec; -} - notrace static noinline int do_monotonic(struct timespec *ts) { unsigned long seq, ns, secs; @@ -82,7 +65,17 @@ notrace static noinline int do_monotonic(struct timespec *ts) secs += gtod->wall_to_monotonic.tv_sec; ns += gtod->wall_to_monotonic.tv_nsec; } while (unlikely(read_seqretry(>od->lock, seq))); - vset_normalized_timespec(ts, secs, ns); + + /* wall_time_nsec, vgetns(), and wall_to_monotonic.tv_nsec + * are all guaranteed to be nonnegative. + */ + while (ns >= NSEC_PER_SEC) { + ns -= NSEC_PER_SEC; + ++secs; + } + ts->tv_sec = secs; + ts->tv_nsec = ns; + return 0; } @@ -107,7 +100,17 @@ notrace static noinline int do_monotonic_coarse(struct timespec *ts) secs += gtod->wall_to_monotonic.tv_sec; ns += gtod->wall_to_monotonic.tv_nsec; } while (unlikely(read_seqretry(>od->lock, seq))); - vset_normalized_timespec(ts, secs, ns); + + /* wall_time_nsec and wall_to_monotonic.tv_nsec are + * guaranteed to be between 0 and NSEC_PER_SEC. + */ + if (ns >= NSEC_PER_SEC) { + ns -= NSEC_PER_SEC; + ++secs; + } + ts->tv_sec = secs; + ts->tv_nsec = ns; + return 0; } @@ -157,3 +160,32 @@ notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) } int gettimeofday(struct timeval *, struct timezone *) __attribute__((weak, alias("__vdso_gettimeofday"))); + +/* This will break when the xtime seconds get inaccurate, but that is + * unlikely */ + +static __always_inline long time_syscall(long *t) +{ + long secs; + asm volatile("syscall" + : "=a" (secs) + : "0" (__NR_time), "D" (t) : "cc", "r11", "cx", "memory"); + return secs; +} + +notrace time_t __vdso_time(time_t *t) +{ + time_t result; + + if (unlikely(!VVAR(vsyscall_gtod_data).sysctl_enabled)) + return time_syscall(t); + + /* This is atomic on x86_64 so we don't need any locks. */ + result = ACCESS_ONCE(VVAR(vsyscall_gtod_data).wall_time_sec); + + if (t) + *t = result; + return result; +} +int time(time_t *t) + __attribute__((weak, alias("__vdso_time"))); diff --git a/arch/x86/vdso/vdso.lds.S b/arch/x86/vdso/vdso.lds.S index 4e5dd3b4de7f..b96b2677cad8 100644 --- a/arch/x86/vdso/vdso.lds.S +++ b/arch/x86/vdso/vdso.lds.S @@ -23,15 +23,10 @@ VERSION { __vdso_gettimeofday; getcpu; __vdso_getcpu; + time; + __vdso_time; local: *; }; } VDSO64_PRELINK = VDSO_PRELINK; - -/* - * Define VDSO64_x for each VEXTERN(x), for use via VDSO64_SYMBOL. - */ -#define VEXTERN(x) VDSO64_ ## x = vdso_ ## x; -#include "vextern.h" -#undef VEXTERN diff --git a/arch/x86/vdso/vextern.h b/arch/x86/vdso/vextern.h deleted file mode 100644 index 1683ba2ae3e8..000000000000 --- a/arch/x86/vdso/vextern.h +++ /dev/null @@ -1,16 +0,0 @@ -#ifndef VEXTERN -#include <asm/vsyscall.h> -#define VEXTERN(x) \ - extern typeof(x) *vdso_ ## x __attribute__((visibility("hidden"))); -#endif - -#define VMAGIC 0xfeedbabeabcdefabUL - -/* Any kernel variables used in the vDSO must be exported in the main - kernel's vmlinux.lds.S/vsyscall.h/proper __section and - put into vextern.h and be referenced as a pointer with vdso prefix. - The main kernel later fills in the values. */ - -VEXTERN(jiffies) -VEXTERN(vgetcpu_mode) -VEXTERN(vsyscall_gtod_data) diff --git a/arch/x86/vdso/vgetcpu.c b/arch/x86/vdso/vgetcpu.c index 9fbc6b20026b..5463ad558573 100644 --- a/arch/x86/vdso/vgetcpu.c +++ b/arch/x86/vdso/vgetcpu.c @@ -11,14 +11,13 @@ #include <linux/time.h> #include <asm/vsyscall.h> #include <asm/vgtod.h> -#include "vextern.h" notrace long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) { unsigned int p; - if (*vdso_vgetcpu_mode == VGETCPU_RDTSCP) { + if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) { /* Load per CPU data from RDTSCP */ native_read_tscp(&p); } else { diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c index 4b5d26f108bb..7abd2be0f9b9 100644 --- a/arch/x86/vdso/vma.c +++ b/arch/x86/vdso/vma.c @@ -15,9 +15,6 @@ #include <asm/proto.h> #include <asm/vdso.h> -#include "vextern.h" /* Just for VMAGIC. */ -#undef VEXTERN - unsigned int __read_mostly vdso_enabled = 1; extern char vdso_start[], vdso_end[]; @@ -26,20 +23,10 @@ extern unsigned short vdso_sync_cpuid; static struct page **vdso_pages; static unsigned vdso_size; -static inline void *var_ref(void *p, char *name) -{ - if (*(void **)p != (void *)VMAGIC) { - printk("VDSO: variable %s broken\n", name); - vdso_enabled = 0; - } - return p; -} - static int __init init_vdso_vars(void) { int npages = (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE; int i; - char *vbase; vdso_size = npages << PAGE_SHIFT; vdso_pages = kmalloc(sizeof(struct page *) * npages, GFP_KERNEL); @@ -54,20 +41,6 @@ static int __init init_vdso_vars(void) copy_page(page_address(p), vdso_start + i*PAGE_SIZE); } - vbase = vmap(vdso_pages, npages, 0, PAGE_KERNEL); - if (!vbase) - goto oom; - - if (memcmp(vbase, "\177ELF", 4)) { - printk("VDSO: I'm broken; not ELF\n"); - vdso_enabled = 0; - } - -#define VEXTERN(x) \ - *(typeof(__ ## x) **) var_ref(VDSO64_SYMBOL(vbase, x), #x) = &__ ## x; -#include "vextern.h" -#undef VEXTERN - vunmap(vbase); return 0; oom: diff --git a/arch/x86/vdso/vvar.c b/arch/x86/vdso/vvar.c deleted file mode 100644 index 1b7e703684f9..000000000000 --- a/arch/x86/vdso/vvar.c +++ /dev/null @@ -1,12 +0,0 @@ -/* Define pointer to external vDSO variables. - These are part of the vDSO. The kernel fills in the real addresses - at boot time. This is done because when the vdso is linked the - kernel isn't yet and we don't know the final addresses. */ -#include <linux/kernel.h> -#include <linux/time.h> -#include <asm/vsyscall.h> -#include <asm/timex.h> -#include <asm/vgtod.h> - -#define VEXTERN(x) typeof (__ ## x) *const vdso_ ## x = (void *)VMAGIC; -#include "vextern.h" |