Fix vDSO support for all supported architectures.

- Cleanup dl-vdso.c code.
- Pass `void *` as first arg to `load_vdso()`, using 32-bit type
  is completely wrong on 64bit architectures.
- Split libc code and vDSO-related code.
  Move arch-specific implementations into separate files.

The performance improvement is for example 50-60 times on ARMv7
and about 4 times on x86_64.

Signed-off-by: Dmitry Chestnykh <dm.chestnykh@gmail.com>

1 files changed, 68 insertions, 0 deletions

diff --git a/ldso/ldso/dl-vdso-calls.h b/ldso/ldso/dl-vdso-calls.h
new file mode 100644
index 000000000..c72f2dadf
--- /dev/null
+++ b/ldso/ldso/dl-vdso-calls.h
@@ -0,0 +1,68 @@
+#ifndef _DL_VDSO_CALLS_H
+#define _DL_VDSO_CALLS_H
+
+#include <sys/time.h>
+#include <sys/syscall.h>
+#include <errno.h>
+#include <time.h>
+
+void __attribute__((weak)) *_get__dl__vdso_clock_gettime(void);
+#if defined(__UCLIBC_USE_TIME64__)
+#include "internal/time64_helpers.h"
+void __attribute__((weak)) *_get__dl__vdso_clock_gettime64(void);
+typedef int (*clock_gettime_func)(clockid_t clock_id, struct __ts64_struct *tp);
+#else
+typedef int (*clock_gettime_func)(clockid_t clock_id, struct timespec *tp);
+#endif
+
+extern int __libc_clock_gettime(clockid_t clock_id, struct timespec *tp);
+
+static int __attribute__ ((used)) __generic_vdso_clock_gettime(clockid_t clock_id, struct timespec *tp);
+static int __attribute__ ((used)) __generic_vdso_clock_gettime(clockid_t clock_id, struct timespec *tp)
+{
+    void *impl = NULL;
+#if defined(__UCLIBC_USE_TIME64__)
+    if (&_get__dl__vdso_clock_gettime64 && (impl = _get__dl__vdso_clock_gettime64())) {
+        struct __ts64_struct __ts64;
+        int __ret = ((clock_gettime_func)impl)(clock_id, &__ts64);
+        if (__ret != 0) {
+            __set_errno(-__ret);
+            return -1;
+        }
+
+        if (tp) {
+            tp->tv_sec = __ts64.tv_sec;
+            tp->tv_nsec = __ts64.tv_nsec;
+        }
+        return 0;
+    }
+
+    /* fallback to syscall */
+    return __libc_clock_gettime(clock_id, tp);
+#else
+    if (&_get__dl__vdso_clock_gettime && (impl = _get__dl__vdso_clock_gettime())) {
+        int __ret = ((clock_gettime_func)impl)(clock_id, tp);
+        if (__ret != 0) {
+            __set_errno(-__ret);
+            return -1;
+        }
+
+        return 0;
+    }
+
+    /* fallback to syscall */
+    return __libc_clock_gettime(clock_id, tp);
+#endif
+}
+
+static int __attribute__ ((used)) __generic_vdso_gettimeofday(struct timeval *tv, __timezone_ptr_t tz)
+{
+    struct timespec ts;
+    int __res = __generic_vdso_clock_gettime(CLOCK_REALTIME, &ts);
+    tv->tv_sec = ts.tv_sec;
+    tv->tv_usec = (suseconds_t)ts.tv_nsec / 1000;
+
+    return __res;
+}
+
+#endif /* _DL_VDSO_CALLS_H */
\ No newline at end of file