Re: [PATCH v4] Enable VDSO on x86_64 statically linked programs.

[Rafael Avila de Espindola <rafael at espindo dot la>]

> > object-suffixes += .os
> > -CPPFLAGS-.os = -DPIC -DSHARED
> > +CPPFLAGS-.os = -DPIC -DSHARED -DUSE_VSYSCALL
> > CFLAGS-.os = $(filter %frame-pointer,$(+cflags)) $(pic-ccflag)
> > libtype.os := lib%_pic.a
> >
> > This can be changed by a sysdep makefile
> >
> > =========================================
>
> This doesn't seem to be the right place to define the macro. We also
> prefer macros that are always defined and which change there value
> between 0 and 1.
>
> USE_VSYSCALL seems to be a Linux thing and thus should go into
> sysdeps/unix/sysv/linux.
>
> It may be clearer to define
>
> #define USE_VSYSCALL (defined (SHARED) || ALWAYS_USE_VSYSCALL)
>
> and then default ALWAYS_USE_VSYSCALL to 0 and override that to 1 for
> x86_64.


Thanks. A new version is attached and it uses your suggestion.

The new ChangeLog is

2018-11-12  Rafael Ávila de Espíndola  <rafael@espindo.la>

        [BZ #19767]
        * nptl/Makefile: Add tst-cond11-static to tests-static and tests.
        * nptl/tst-cond11-static.c: New File.
        * sysdeps/unix/sysv/linux/Makefile: Add tst-affinity-static to
          tests-static and tests
        * sysdeps/unix/sysv/linux/sysdep-vdso.h: Use USE_VSYSCALL instead
          of SHARED.
	* sysdeps/unix/sysv/linux/sysdep.h: Define ALWAYS_USE_VSYSCALL and
	  USE_VSYSCALL.
        * sysdeps/unix/sysv/linux/tst-affinity-static.c: New file.
        * sysdeps/unix/sysv/linux/x86/libc-vdso.h: Use USE_VSYSCALL
          instead of SHARED.
        * sysdeps/unix/sysv/linux/x86_64/init-first.c: remove #ifdef SHARED.
        * sysdeps/unix/sysv/linux/x86_64/sysdep.h: define ALWAYS_USE_VSYSCALL.


Cheers,
Rafael

From e035a9e1da87daec5e0b8f735734df42e595646b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafael=20=C3=81vila=20de=20Esp=C3=ADndola?=
 <rafael@espindo.la>
Date: Thu, 8 Nov 2018 23:25:31 -0800
Subject: [PATCH] Enable VDSO on x86_64 statically linked programs.

All the required code already existed, and some of it was already
running.

AT_SYSINFO_EHDR is processed if NEED_DL_SYSINFO_DSO is defined, but it
looks like it always is. The call to setup_vdso is also unconditional,
so all that was left to do was setup the function pointers and use
them. This patch just deletes some #ifdef to enable that.
---
 nptl/Makefile                                 |  5 +++--
 nptl/tst-cond11-static.c                      |  1 +
 sysdeps/unix/sysv/linux/Makefile              |  3 +++
 sysdeps/unix/sysv/linux/sysdep-vdso.h         |  4 ++--
 sysdeps/unix/sysv/linux/sysdep.h              |  7 +++++++
 sysdeps/unix/sysv/linux/tst-affinity-static.c |  1 +
 sysdeps/unix/sysv/linux/x86/libc-vdso.h       |  2 +-
 sysdeps/unix/sysv/linux/x86_64/init-first.c   | 12 +++++-------
 sysdeps/unix/sysv/linux/x86_64/sysdep.h       |  3 +++
 9 files changed, 26 insertions(+), 12 deletions(-)
 create mode 100644 nptl/tst-cond11-static.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-affinity-static.c

diff --git a/nptl/Makefile b/nptl/Makefile
index 49b6faa330..982e43adfa 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -449,9 +449,10 @@ link-libc-static := $(common-objpfx)libc.a $(static-gnulib) \
 tests-static += tst-locale1 tst-locale2 tst-stackguard1-static \
 		tst-cancel21-static tst-cancel24-static tst-cond8-static \
 		tst-mutex8-static tst-mutexpi8-static tst-sem11-static \
-		tst-sem12-static
+		tst-sem12-static tst-cond11-static
+
 tests += tst-cancel21-static tst-cancel24-static \
-	 tst-cond8-static
+	 tst-cond8-static tst-cond11-static
 tests-internal += tst-sem11-static tst-sem12-static tst-stackguard1-static
 xtests-static += tst-setuid1-static
 
diff --git a/nptl/tst-cond11-static.c b/nptl/tst-cond11-static.c
new file mode 100644
index 0000000000..9bccb8ec8b
--- /dev/null
+++ b/nptl/tst-cond11-static.c
@@ -0,0 +1 @@
+#include "tst-cond11.c"
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 72b6b641d5..362cf3b950 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -146,6 +146,9 @@ sysdep_routines += sched_getcpu oldglob
 
 tests += tst-affinity tst-affinity-pid
 
+tests-static := tst-affinity-static
+tests += $(tests-static)
+
 CFLAGS-fork.c = $(libio-mtsafe)
 CFLAGS-getpid.o = -fomit-frame-pointer
 CFLAGS-getpid.os = -fomit-frame-pointer
diff --git a/sysdeps/unix/sysv/linux/sysdep-vdso.h b/sysdeps/unix/sysv/linux/sysdep-vdso.h
index 7f894c5e02..1ee0657ad3 100644
--- a/sysdeps/unix/sysv/linux/sysdep-vdso.h
+++ b/sysdeps/unix/sysv/linux/sysdep-vdso.h
@@ -26,7 +26,7 @@
      funcptr (args)
 #endif
 
-#if defined SHARED && defined HAVE_VSYSCALL
+#if USE_VSYSCALL && defined HAVE_VSYSCALL
 
 # include <libc-vdso.h>
 
@@ -84,6 +84,6 @@
 # define INTERNAL_VSYSCALL(name, err, nr, args...) \
    INTERNAL_SYSCALL (name, err, nr, ##args)
 
-#endif /* defined SHARED && defined HAVE_VSYSCALL */
+#endif /* USE_VSYSCALL && defined HAVE_VSYSCALL */
 
 #endif /* SYSDEP_VDSO_LINUX_H  */
diff --git a/sysdeps/unix/sysv/linux/sysdep.h b/sysdeps/unix/sysv/linux/sysdep.h
index 4fd0a9bae3..9655436ee4 100644
--- a/sysdeps/unix/sysv/linux/sysdep.h
+++ b/sysdeps/unix/sysv/linux/sysdep.h
@@ -18,6 +18,13 @@
 #include <bits/wordsize.h>
 #include <kernel-features.h>
 
+/* By default only shared builds use vdso. */
+#ifndef ALWAYS_USE_VSYSCALL
+#define ALWAYS_USE_VSYSCALL 0
+#endif
+
+#define USE_VSYSCALL (defined (SHARED) || ALWAYS_USE_VSYSCALL)
+
 /* Set error number and return -1.  A target may choose to return the
    internal function, __syscall_error, which sets errno and returns -1.
    We use -1l, instead of -1, so that it can be casted to (void *).  */
diff --git a/sysdeps/unix/sysv/linux/tst-affinity-static.c b/sysdeps/unix/sysv/linux/tst-affinity-static.c
new file mode 100644
index 0000000000..4022ea317a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-affinity-static.c
@@ -0,0 +1 @@
+#include "tst-affinity.c"
diff --git a/sysdeps/unix/sysv/linux/x86/libc-vdso.h b/sysdeps/unix/sysv/linux/x86/libc-vdso.h
index 6f86073dae..b9b4b93011 100644
--- a/sysdeps/unix/sysv/linux/x86/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/x86/libc-vdso.h
@@ -22,7 +22,7 @@
 #include <time.h>
 #include <sys/time.h>
 
-#ifdef SHARED
+#if USE_VSYSCALL
 
 # include <sysdep-vdso.h>
 
diff --git a/sysdeps/unix/sysv/linux/x86_64/init-first.c b/sysdeps/unix/sysv/linux/x86_64/init-first.c
index 2320505804..ad19f4b055 100644
--- a/sysdeps/unix/sysv/linux/x86_64/init-first.c
+++ b/sysdeps/unix/sysv/linux/x86_64/init-first.c
@@ -16,11 +16,10 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#ifdef SHARED
-# include <time.h>
-# include <sysdep.h>
-# include <dl-vdso.h>
-# include <libc-vdso.h>
+#include <time.h>
+#include <sysdep.h>
+#include <dl-vdso.h>
+#include <libc-vdso.h>
 
 long int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
   attribute_hidden;
@@ -46,7 +45,6 @@ __vdso_platform_setup (void)
   VDSO_SYMBOL(getcpu) = p;
 }
 
-# define VDSO_SETUP __vdso_platform_setup
-#endif
+#define VDSO_SETUP __vdso_platform_setup
 
 #include <csu/init-first.c>
diff --git a/sysdeps/unix/sysv/linux/x86_64/sysdep.h b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
index f07eb04962..9f49347ce5 100644
--- a/sysdeps/unix/sysv/linux/x86_64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
@@ -18,6 +18,9 @@
 #ifndef _LINUX_X86_64_SYSDEP_H
 #define _LINUX_X86_64_SYSDEP_H 1
 
+/* Always enable vsyscalls on x86_64 */
+#define ALWAYS_USE_VSYSCALL 1
+
 /* There is some commonality.  */
 #include <sysdeps/unix/sysv/linux/sysdep.h>
 #include <sysdeps/unix/x86_64/sysdep.h>
-- 
2.19.1