On powerpc, __arch_get_vdso_data() clobbers the link register,
requiring the caller to save it.

As the parent function already has to set a stack frame and saves
the link register before calling the C vdso function, retriving the
vdso data pointer there is lighter.

Give architectures the opportunity to hand the vdso data pointer
to C vdso functions.

Signed-off-by: Christophe Leroy <[email protected]>
---
 lib/vdso/gettimeofday.c | 83 +++++++++++++++++++++++++++++++++--------
 1 file changed, 67 insertions(+), 16 deletions(-)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index f8b8ec5e63ac..72d65dd50cb4 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -206,9 +206,9 @@ static __always_inline int do_coarse(const struct vdso_data 
*vd, clockid_t clk,
 }
 
 static __maybe_unused int
-__cvdso_clock_gettime_common(clockid_t clock, struct __kernel_timespec *ts)
+__cvdso_clock_gettime_common(const struct vdso_data *vd, clockid_t clock,
+                            struct __kernel_timespec *ts)
 {
-       const struct vdso_data *vd = __arch_get_vdso_data();
        u32 msk;
 
        /* Check for negative values or invalid clocks */
@@ -233,23 +233,33 @@ __cvdso_clock_gettime_common(clockid_t clock, struct 
__kernel_timespec *ts)
 }
 
 static __maybe_unused int
-__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
+__cvdso_clock_gettime_data(const struct vdso_data *vd, clockid_t clock,
+                          struct __kernel_timespec *ts)
 {
-       int ret = __cvdso_clock_gettime_common(clock, ts);
+       int ret = __cvdso_clock_gettime_common(vd, clock, ts);
 
        if (unlikely(ret))
                return clock_gettime_fallback(clock, ts);
        return 0;
 }
 
+static __maybe_unused int
+__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
+{
+       const struct vdso_data *vd = __arch_get_vdso_data();
+
+       return __cvdso_clock_gettime_data(vd, clock, ts);
+}
+
 #ifdef BUILD_VDSO32
 static __maybe_unused int
-__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
+__cvdso_clock_gettime32_data(const struct vdso_data *vd, clockid_t clock,
+                            struct old_timespec32 *res)
 {
        struct __kernel_timespec ts;
        int ret;
 
-       ret = __cvdso_clock_gettime_common(clock, &ts);
+       ret = __cvdso_clock_gettime_common(vd, clock, &ts);
 
        if (unlikely(ret))
                return clock_gettime32_fallback(clock, res);
@@ -260,13 +270,21 @@ __cvdso_clock_gettime32(clockid_t clock, struct 
old_timespec32 *res)
 
        return ret;
 }
-#endif /* BUILD_VDSO32 */
 
 static __maybe_unused int
-__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
+__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
 {
        const struct vdso_data *vd = __arch_get_vdso_data();
 
+       return __cvdso_clock_gettime32_data(vd, clock, res);
+}
+#endif /* BUILD_VDSO32 */
+
+static __maybe_unused int
+__cvdso_gettimeofday_data(const struct vdso_data *vd,
+                         struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+
        if (likely(tv != NULL)) {
                struct __kernel_timespec ts;
 
@@ -289,10 +307,18 @@ __cvdso_gettimeofday(struct __kernel_old_timeval *tv, 
struct timezone *tz)
        return 0;
 }
 
-#ifdef VDSO_HAS_TIME
-static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t 
*time)
+static __maybe_unused int
+__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
 {
        const struct vdso_data *vd = __arch_get_vdso_data();
+
+       return __cvdso_gettimeofday_data(vd, tv, tz);
+}
+
+#ifdef VDSO_HAS_TIME
+static __maybe_unused __kernel_old_time_t
+__cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time)
+{
        __kernel_old_time_t t;
 
        if (IS_ENABLED(CONFIG_TIME_NS) && vd->clock_mode == VCLOCK_TIMENS)
@@ -305,13 +331,20 @@ static __maybe_unused __kernel_old_time_t 
__cvdso_time(__kernel_old_time_t *time
 
        return t;
 }
+
+static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t 
*time)
+{
+       const struct vdso_data *vd = __arch_get_vdso_data();
+
+       return __cvdso_time_data(vd, time);
+}
 #endif /* VDSO_HAS_TIME */
 
 #ifdef VDSO_HAS_CLOCK_GETRES
 static __maybe_unused
-int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res)
+int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
+                               struct __kernel_timespec *res)
 {
-       const struct vdso_data *vd = __arch_get_vdso_data();
        u32 msk;
        u64 ns;
 
@@ -349,23 +382,33 @@ int __cvdso_clock_getres_common(clockid_t clock, struct 
__kernel_timespec *res)
 }
 
 static __maybe_unused
-int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
+int __cvdso_clock_getres_data(const struct vdso_data *vd, clockid_t clock,
+                             struct __kernel_timespec *res)
 {
-       int ret = __cvdso_clock_getres_common(clock, res);
+       int ret = __cvdso_clock_getres_common(vd, clock, res);
 
        if (unlikely(ret))
                return clock_getres_fallback(clock, res);
        return 0;
 }
 
+static __maybe_unused
+int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
+{
+       const struct vdso_data *vd = __arch_get_vdso_data();
+
+       return __cvdso_clock_getres_data(vd, clock, res);
+}
+
 #ifdef BUILD_VDSO32
 static __maybe_unused int
-__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
+__cvdso_clock_getres_time32_data(const struct vdso_data *vd, clockid_t clock,
+                                struct old_timespec32 *res)
 {
        struct __kernel_timespec ts;
        int ret;
 
-       ret = __cvdso_clock_getres_common(clock, &ts);
+       ret = __cvdso_clock_getres_common(vd, clock, &ts);
 
        if (unlikely(ret))
                return clock_getres32_fallback(clock, res);
@@ -376,5 +419,13 @@ __cvdso_clock_getres_time32(clockid_t clock, struct 
old_timespec32 *res)
        }
        return ret;
 }
+
+static __maybe_unused int
+__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
+{
+       const struct vdso_data *vd = __arch_get_vdso_data();
+
+       return __cvdso_clock_getres_time32_data(vd, clock, res);
+}
 #endif /* BUILD_VDSO32 */
 #endif /* VDSO_HAS_CLOCK_GETRES */
-- 
2.25.0

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