8 files changed, 81 insertions, 96 deletions

diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile
index 4a2afa1bac51..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
@@ -25,7 +25,7 @@ targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
 
 export CPPFLAGS_vdso.lds += -P -C
 
-VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -Wl,-soname=linux-vdso.so.1 \
+VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
                         -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
 
 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
@@ -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
 
@@ -69,7 +82,7 @@ vdso32.so-$(VDSO32-y)		+= sysenter
 vdso32-images                   = $(vdso32.so-y:%=vdso32-%.so)
 
 CPPFLAGS_vdso32.lds = $(CPPFLAGS_vdso.lds)
-VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -Wl,-soname=linux-gate.so.1
+VDSO_LDFLAGS_vdso32.lds = -m32 -Wl,-soname=linux-gate.so.1
 
 # This makes sure the $(obj) subdirectory exists even though vdso32/
 # is not a kbuild sub-make subdirectory.
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(&gtod->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(&gtod->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/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 36df991985b2..468d591dde31 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -417,24 +417,25 @@ const char *arch_vma_name(struct vm_area_struct *vma)
         return NULL;
 }
 
-struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 {
-        struct mm_struct *mm = tsk->mm;
-
-        /* Check to see if this task was created in compat vdso mode */
+        /*
+         * Check to see if the corresponding task was created in compat vdso
+         * mode.
+         */
         if (mm && mm->context.vdso == (void *)VDSO_HIGH_BASE)
                 return &gate_vma;
         return NULL;
 }
 
-int in_gate_area(struct task_struct *task, unsigned long addr)
+int in_gate_area(struct mm_struct *mm, unsigned long addr)
 {
-        const struct vm_area_struct *vma = get_gate_vma(task);
+        const struct vm_area_struct *vma = get_gate_vma(mm);
 
         return vma && addr >= vma->vm_start && addr < vma->vm_end;
 }
 
-int in_gate_area_no_task(unsigned long addr)
+int in_gate_area_no_mm(unsigned long addr)
 {
         return 0;
 }
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"