This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
[PATCH v2] powerpc: Fix static-linked version of __ppc_get_timebase_freq [BZ #24640]
- From: Raoni Fassina Firmino <raoni at linux dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Date: Wed, 19 Jun 2019 15:09:01 -0300
- Subject: [PATCH v2] powerpc: Fix static-linked version of __ppc_get_timebase_freq [BZ #24640]
From: Stan Shebs <stanshebs@google.com>
Originally part of a larger pathset[1].
Changes since v1:
- Merged fix & testcase in one patch.
Originally patches #1 and #2[2,3].
[1] https://www.sourceware.org/ml/libc-alpha/2019-06/msg00283.html
[2] https://www.sourceware.org/ml/libc-alpha/2019-06/msg00284.html
[3] https://www.sourceware.org/ml/libc-alpha/2019-06/msg00285.html
---- 8< ----
__ppc_get_timebase_freq() always return 0 when using static linked
glibc.
This is a minimal example.c to reproduce:
/******************************/
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <sys/platform/ppc.h>
int main() {
uint64_t freq = __ppc_get_timebase_freq();
printf("Time Base frequency = %"PRIu64" Hz\n", freq);
if (freq == 0)
return -1;
return 0;
}
/******************************/
Compile command: gcc -static example.c
This bug has been reproduced, fixed and tested on all powerpc platforms
(ppc32, ppc64 and ppc64le).
The underlying code of __ppc_get_timebase_freq uses __get_timebase_freq
that has a different implementation for shared and static version of
glibc. In the static version, there is an incorrect sense in the if
check for the fd returned when opening /proc/cpuinfo.
This solution is mostly a cherry-pick from:
commit 4791e4f773d060c1a37b27aac5b03cdfa9327afc
Author: Stan Shebs <stanshebs@google.com>
Date: Fri May 17 12:25:19 2019 -0700
Subject: Fix sense of a test in the static-linking version of ppc get_clockfreq
That is in branch glibc/google/grte/v5-2.27/master and was mentioned for
inclusion on master here:
https://www.sourceware.org/ml/libc-alpha/2019-05/msg00409.html
Adapted from original fix for get_clockfreq. That code was moved to
get_timebase_freq.
Also added a static-build testcase for __ppc_get_timebase_freq since the
underlying function has different implementations for shared and static
build.
ChangeLog:
2019-06-19 Stan Shebs <stanshebs@google.com>
Raoni Fassina Firmino <raoni@linux.ibm.com>
[BZ #24640]
* sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c
[!SHARED] (__get_timebase_freq): Fix sense of a test in the
static-linking version.
* sysdeps/unix/sysv/linux/powerpc/Makefile
(tests-static): Add test-gettimebasefreq-static.
(tests): Likewise.
* sysdeps/unix/sysv/linux/powerpc/test-gettimebasefreq-static.c:
New file.
---
sysdeps/unix/sysv/linux/powerpc/Makefile | 2 ++
.../sysv/linux/powerpc/get_timebase_freq.c | 2 +-
.../powerpc/test-gettimebasefreq-static.c | 19 +++++++++++++++++++
3 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 sysdeps/unix/sysv/linux/powerpc/test-gettimebasefreq-static.c
diff --git a/sysdeps/unix/sysv/linux/powerpc/Makefile b/sysdeps/unix/sysv/linux/powerpc/Makefile
index 19ac59d862..4b7198dcec 100644
--- a/sysdeps/unix/sysv/linux/powerpc/Makefile
+++ b/sysdeps/unix/sysv/linux/powerpc/Makefile
@@ -25,6 +25,8 @@ endif
ifeq ($(subdir),misc)
sysdep_headers += bits/ppc.h
sysdep_routines += get_timebase_freq
+tests-static += test-gettimebasefreq-static
+tests += test-gettimebasefreq-static
tests += test-gettimebasefreq
tests += test-powerpc-linux-sysconf
endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c
index 23e7694d87..c245e97526 100644
--- a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c
+++ b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c
@@ -39,7 +39,7 @@ __get_timebase_freq (void)
timebase : 33333333
We search for this line and convert the number into an integer. */
int fd = __open_nocancel ("/proc/cpuinfo", O_RDONLY);
- if (__glibc_likely (fd != -1))
+ if (__glibc_unlikely (fd == -1))
return result;
/* The timebase will be in the 1st 1024 bytes for systems with up
diff --git a/sysdeps/unix/sysv/linux/powerpc/test-gettimebasefreq-static.c b/sysdeps/unix/sysv/linux/powerpc/test-gettimebasefreq-static.c
new file mode 100644
index 0000000000..58b4eee98d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/test-gettimebasefreq-static.c
@@ -0,0 +1,19 @@
+/* Check __ppc_get_timebase_freq() for architecture changes
+ Copyright (C) 2019 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include "test-gettimebasefreq.c"
--
2.20.1