2011-2014 Thomas Backlund <tmb@mageia.org>
* Rebased / adapted for new glibc
2006-05-17 Gwenole Beauchesne <gbeauchesne@mandriva.com>
* Update and simplify for glibc 2.4.90.
2002-12-07 Gwenole Beauchesne <gbeauchesne@mandrakesoft.com>
Let an i586 rtld load i686 libraries (especially libpthread)
* elf/rtld.c (HP_TIMING_AVAIL): Redefine to HP_TIMING_HWCAP_AVAIL
since early statistics require high-precision timers.
* sysdeps/generic/ldsodefs.h (rtld_global): Declare
_dl_cpuclock_offset if HP_TIMING_HWCAP_AVAIL is defined too.
* sysdeps/unix/sysv/linux/i386/i586/Makefile: New file.
* sysdeps/unix/sysv/linux/i386/i586/hp-timing.c: New file.
* sysdeps/unix/sysv/linux/i386/i586/hp-timing.h: New file.
---
elf/rtld.c | 12 ++++++++++-
sysdeps/generic/ldsodefs.h | 2 -
sysdeps/i386/i586/Makefile | 4 +++
sysdeps/i386/i586/hp-timing.c | 2 +
sysdeps/i386/i586/hp-timing.h | 43 ++++++++++++++++++++++++++++++++++++++++++
diff -Nurp glibc-2.20.orig/elf/rtld.c glibc-2.20/elf/rtld.c
--- glibc-2.20.orig/elf/rtld.c 2014-09-07 11:09:09.000000000 +0300
+++ glibc-2.20/elf/rtld.c 2014-09-08 18:12:17.640928030 +0300
@@ -16,6 +16,9 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
+/* Early statistics require high-precision timing. */
+#define NEED_HP_TIMING_HWCAP_AVAIL 1
+
#include <errno.h>
#include <dlfcn.h>
#include <fcntl.h>
@@ -195,6 +198,12 @@ static void dl_main (const ElfW(Phdr) *p
static struct libname_list _dl_rtld_libname;
static struct libname_list _dl_rtld_libname2;
+/* Run-time detect availability of high-precision timer? */
+#ifdef HP_TIMING_HWCAP_AVAIL
+# undef HP_SMALL_TIMING_AVAIL
+# define HP_SMALL_TIMING_AVAIL HP_TIMING_HWCAP_AVAIL
+#endif
+
/* Variable for statistics. */
#ifndef HP_TIMING_NONAVAIL
static hp_timing_t relocate_time;
@@ -296,7 +305,8 @@ _dl_start_final (void *arg, struct dl_st
# endif
#endif
- HP_TIMING_NOW (GL(dl_cpuclock_offset));
+ if (HP_SMALL_TIMING_AVAIL)
+ HP_TIMING_NOW (GL(dl_cpuclock_offset));
/* Initialize the stack end variable. */
__libc_stack_end = __builtin_frame_address (0);
diff -Nurp glibc-2.20.orig/sysdeps/generic/ldsodefs.h glibc-2.20/sysdeps/generic/ldsodefs.h
--- glibc-2.20.orig/sysdeps/generic/ldsodefs.h 2014-09-07 11:09:09.000000000 +0300
+++ glibc-2.20/sysdeps/generic/ldsodefs.h 2014-09-08 18:17:19.655631175 +0300
@@ -319,7 +319,7 @@ struct rtld_global
/* The object to be initialized first. */
EXTERN struct link_map *_dl_initfirst;
-#if HP_SMALL_TIMING_AVAIL
+#if HP_SMALL_TIMING_AVAIL || defined HP_TIMING_HWCAP_AVAIL
/* Start time on CPU clock. */
EXTERN hp_timing_t _dl_cpuclock_offset;
#endif
diff -Nurp glibc-2.20.orig/sysdeps/i386/i586/hp-timing.h glibc-2.20/sysdeps/i386/i586/hp-timing.h
--- glibc-2.20.orig/sysdeps/i386/i586/hp-timing.h 1970-01-01 02:00:00.000000000 +0200
+++ glibc-2.20/sysdeps/i386/i586/hp-timing.h 2014-09-08 18:07:38.466353624 +0300
@@ -0,0 +1,43 @@
+#ifndef _HP_HWCAP_TIMING_H
+#define _HP_HWCAP_TIMING_H 1
+
+/* We can use the i686 implementation with slight changes. */
+#include <sysdeps/i386/i686/hp-timing.h>
+
+/* We need the definition of HWCAP_I386_TSC. */
+#include <sysdeps/i386/dl-hwcapinfo.h>
+
+/* We need to perform a runtime check for the timestamp register. */
+#undef HP_SMALL_TIMING_AVAIL
+#define HP_SMALL_TIMING_AVAIL (0)
+
+/* HP_TIMING_HWCAP_AVAIL: this macro performs a run-time check for the
+ capability. */
+#define HP_TIMING_HWCAP_AVAIL (_dl_hp_timing_avail())
+
+/* Perform the TSC check. */
+#ifdef NEED_HP_TIMING_HWCAP_AVAIL
+static inline
+unsigned int
+_dl_cpuid_edx (unsigned int op)
+{
+ unsigned int edx;
+ __asm__ __volatile__("push %%ebx ; cpuid ; pop %%ebx"
+ : "=d" (edx) : "a" (op) : "ecx");
+ return edx;
+}
+
+static int
+internal_function
+_dl_hp_timing_avail (void)
+{
+ static int has_tsc = -1;
+
+ if (__builtin_expect (has_tsc == -1, 0))
+ has_tsc = (_dl_cpuid_edx(1) & HWCAP_I386_TSC) == HWCAP_I386_TSC;
+
+ return has_tsc;
+}
+#endif
+
+#endif /* hp-timing.h */
