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S390: Add support for vdso getcpu symbol.
- From: Stefan Liebler <stli at linux dot vnet dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Date: Fri, 29 Apr 2016 09:42:14 +0200
- Subject: S390: Add support for vdso getcpu symbol.
- Authentication-results: sourceware.org; auth=none
Hi,
This patch adds support for symbol __kernel_getcpu in vDSO,
which is available with kernel 4.5.
Now sched_getcpu is using this symbol if available in mapped vDSO
by defining macro HAVE_GETCPU_VSYSCALL. If not available at runtime,
the former syscall is used.
Bye
Stefan
ChangeLog:
* sysdeps/unix/sysv/linux/s390/init-first.c:
Add VDSO_SYMBOL(getcpu).
(_libc_vdso_platform_setup): Initialize VDSO_SYMBOL(getcpu).
* sysdeps/unix/sysv/linux/s390/libc-vdso.h:
Add VDSO_SYMBOL(getcpu).
* sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h:
New define HAVE_GETCPU_VSYSCALL.
* sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h: Likewise.
commit 47c8c56d61660701e18cf17932a6da1b84fcf789
Author: Stefan Liebler <stli@linux.vnet.ibm.com>
Date: Thu Apr 28 17:30:34 2016 +0200
S390: Add support for vdso getcpu symbol.
This patch adds support for symbol __kernel_getcpu in vDSO,
which is available with kernel 4.5.
Now sched_getcpu is using this symbol if available in mapped vDSO
by defining macro HAVE_GETCPU_VSYSCALL. If not available at runtime,
the former syscall is used.
ChangeLog:
* sysdeps/unix/sysv/linux/s390/init-first.c:
Add VDSO_SYMBOL(getcpu).
(_libc_vdso_platform_setup): Initialize VDSO_SYMBOL(getcpu).
* sysdeps/unix/sysv/linux/s390/libc-vdso.h:
Add VDSO_SYMBOL(getcpu).
* sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h:
New define HAVE_GETCPU_VSYSCALL.
* sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h: Likewise.
diff --git a/sysdeps/unix/sysv/linux/s390/init-first.c b/sysdeps/unix/sysv/linux/s390/init-first.c
index d3a20fd..7498cbe 100644
--- a/sysdeps/unix/sysv/linux/s390/init-first.c
+++ b/sysdeps/unix/sysv/linux/s390/init-first.c
@@ -29,6 +29,8 @@ long int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
long int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *)
__attribute__ ((nocommon));
+long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *)
+ attribute_hidden;
static inline void
_libc_vdso_platform_setup (void)
@@ -46,6 +48,10 @@ _libc_vdso_platform_setup (void)
p = _dl_vdso_vsym ("__kernel_clock_getres", &linux2629);
PTR_MANGLE (p);
VDSO_SYMBOL (clock_getres) = p;
+
+ p = _dl_vdso_vsym ("__kernel_getcpu", &linux2629);
+ PTR_MANGLE (p);
+ VDSO_SYMBOL (getcpu) = p;
}
# define VDSO_SETUP _libc_vdso_platform_setup
diff --git a/sysdeps/unix/sysv/linux/s390/libc-vdso.h b/sysdeps/unix/sysv/linux/s390/libc-vdso.h
index d2a8316..512b3ba 100644
--- a/sysdeps/unix/sysv/linux/s390/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/s390/libc-vdso.h
@@ -31,6 +31,8 @@ extern long int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *);
extern long int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *);
+extern long int (*VDSO_SYMBOL(getcpu)) (unsigned *, unsigned *, void *)
+ attribute_hidden;
#endif
#endif /* _LIBC_VDSO_H */
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h b/sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h
index 3540416..651e1ee 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h
@@ -283,6 +283,7 @@
#define HAVE_CLOCK_GETRES_VSYSCALL 1
#define HAVE_CLOCK_GETTIME_VSYSCALL 1
#define HAVE_GETTIMEOFDAY_VSYSCALL 1
+#define HAVE_GETCPU_VSYSCALL 1
/* This version is for internal uses when there is no desire
to set errno */
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
index 6f390ff..702b0b6 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
@@ -289,6 +289,7 @@
#define HAVE_CLOCK_GETRES_VSYSCALL 1
#define HAVE_CLOCK_GETTIME_VSYSCALL 1
#define HAVE_GETTIMEOFDAY_VSYSCALL 1
+#define HAVE_GETCPU_VSYSCALL 1
/* This version is for internal uses when there is no desire
to set errno */