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[PATCH 1/4] 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: Thu, 13 Jun 2019 12:11:42 -0300
- Subject: [PATCH 1/4] powerpc: Fix static-linked version of __ppc_get_timebase_freq [BZ #24640]
- References: <20190613151145.22243-1-raoni@linux.ibm.com>
From: Stan Shebs <stanshebs@google.com>
__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.
ChangeLog:
2019-06-13 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/get_timebase_freq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
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
--
2.20.1