Now that pvclock doesn't require access to the fixmap, all vdso
variants can use it.
The kernel side isn't wired up for 32-bit kernels yet, but this
covers 32-bit and x32 userspace on 64-bit kernels.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/entry/vdso/vclock_gettime.c | 91 ++++++++++++++++--------------------
1 file changed, 40 insertions(+), 51 deletions(-)
diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c
index 59a98c25bde7..8602f06c759f 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -17,8 +17,10 @@
#include <asm/vvar.h>
#include <asm/unistd.h>
#include <asm/msr.h>
+#include <asm/pvclock.h>
#include <linux/math64.h>
#include <linux/time.h>
+#include <linux/kernel.h>
#define gtod (&VVAR(vsyscall_gtod_data))
@@ -43,10 +45,6 @@ extern u8 pvclock_page
#ifndef BUILD_VDSO32
-#include <linux/kernel.h>
-#include <asm/vsyscall.h>
-#include <asm/pvclock.h>
-
notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
{
long ret;
@@ -64,8 +62,42 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
return ret;
}
-#ifdef CONFIG_PARAVIRT_CLOCK
+#else
+
+notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
+{
+ long ret;
+
+ asm(
+ "mov %%ebx, %%edx \n"
+ "mov %2, %%ebx \n"
+ "call __kernel_vsyscall \n"
+ "mov %%edx, %%ebx \n"
+ : "=a" (ret)
+ : "0" (__NR_clock_gettime), "g" (clock), "c" (ts)
+ : "memory", "edx");
+ return ret;
+}
+
+notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
+{
+ long ret;
+
+ asm(
+ "mov %%ebx, %%edx \n"
+ "mov %2, %%ebx \n"
+ "call __kernel_vsyscall \n"
+ "mov %%edx, %%ebx \n"
+ : "=a" (ret)
+ : "0" (__NR_gettimeofday), "g" (tv), "c" (tz)
+ : "memory", "edx");
+ return ret;
+}
+
+#endif
+
+#ifdef CONFIG_PARAVIRT_CLOCK
static notrace const struct pvclock_vsyscall_time_info *get_pvti0(void)
{
return (const struct pvclock_vsyscall_time_info *)&pvclock_page;
@@ -109,9 +141,9 @@ static notrace cycle_t vread_pvclock(int *mode)
do {
version = pvti->version;
- /* This is also a read barrier, so we'll read version first. */
- tsc = rdtsc_ordered();
+ smp_rmb();
+ tsc = rdtsc_ordered();
pvti_tsc_to_system_mul = pvti->tsc_to_system_mul;
pvti_tsc_shift = pvti->tsc_shift;
pvti_system_time = pvti->system_time;
@@ -126,7 +158,7 @@ static notrace cycle_t vread_pvclock(int *mode)
pvclock_scale_delta(delta, pvti_tsc_to_system_mul,
pvti_tsc_shift);
- /* refer to tsc.c read_tsc() comment for rationale */
+ /* refer to vread_tsc() comment for rationale */
last = gtod->cycle_last;
if (likely(ret >= last))
@@ -136,49 +168,6 @@ static notrace cycle_t vread_pvclock(int *mode)
}
#endif
-#else
-
-notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
-{
- long ret;
-
- asm(
- "mov %%ebx, %%edx \n"
- "mov %2, %%ebx \n"
- "call __kernel_vsyscall \n"
- "mov %%edx, %%ebx \n"
- : "=a" (ret)
- : "0" (__NR_clock_gettime), "g" (clock), "c" (ts)
- : "memory", "edx");
- return ret;
-}
-
-notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
-{
- long ret;
-
- asm(
- "mov %%ebx, %%edx \n"
- "mov %2, %%ebx \n"
- "call __kernel_vsyscall \n"
- "mov %%edx, %%ebx \n"
- : "=a" (ret)
- : "0" (__NR_gettimeofday), "g" (tv), "c" (tz)
- : "memory", "edx");
- return ret;
-}
-
-#ifdef CONFIG_PARAVIRT_CLOCK
-
-static notrace cycle_t vread_pvclock(int *mode)
-{
- *mode = VCLOCK_NONE;
- return 0;
-}
-#endif
-
-#endif
-
notrace static cycle_t vread_tsc(void)
{
cycle_t ret = (cycle_t)rdtsc_ordered();
--
2.5.0
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