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Re: [PATCH] [BZ #20072] x86 init_cpu_features is called twice in static executable
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: GNU C Library <libc-alpha at sourceware dot org>
- Date: Fri, 13 May 2016 08:12:35 -0700
- Subject: Re: [PATCH] [BZ #20072] x86 init_cpu_features is called twice in static executable
- Authentication-results: sourceware.org; auth=none
- References: <20160510165004 dot GA13777 at intel dot com>
On Tue, May 10, 2016 at 9:50 AM, H.J. Lu <hongjiu.lu@intel.com> wrote:
> In static executable, since init_cpu_features is called early from
> __libc_start_main, there is no need to call it again in dl_platform_init.
>
> Tested on x86 and x86-64. Any comments, feedbacks?
>
> H.J.
> ---
> [BZ #20072]
> * sysdeps/i386/dl-machine.h (dl_platform_init): Call
> init_cpu_features only if SHARED is defined.
> * sysdeps/x86_64/dl-machine.h (dl_platform_init): Likewise.
I will check in this revised patch today.
--
H.J.
From f8cbec51d151fe1cd9cbbecb6db391734d50e71d Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 10 May 2016 09:44:30 -0700
Subject: [PATCH] Call init_cpu_features only if SHARED is defined
In static executable, since init_cpu_features is called early from
__libc_start_main, there is no need to call it again in dl_platform_init.
[BZ #20072]
* sysdeps/i386/dl-machine.h (dl_platform_init): Call
init_cpu_features only if SHARED is defined.
* sysdeps/x86_64/dl-machine.h (dl_platform_init): Likewise.
---
sysdeps/i386/dl-machine.h | 4 ++++
sysdeps/x86_64/dl-machine.h | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
index 130bcf5..4e3968a 100644
--- a/sysdeps/i386/dl-machine.h
+++ b/sysdeps/i386/dl-machine.h
@@ -237,7 +237,11 @@ dl_platform_init (void)
/* Avoid an empty string which would disturb us. */
GLRO(dl_platform) = NULL;
+#ifdef SHARED
+ /* init_cpu_features has been called early from __libc_start_main in
+ static executable. */
init_cpu_features (&GLRO(dl_x86_cpu_features));
+#endif
}
static inline Elf32_Addr
diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h
index 980ca73..ed0c1a8 100644
--- a/sysdeps/x86_64/dl-machine.h
+++ b/sysdeps/x86_64/dl-machine.h
@@ -224,7 +224,11 @@ dl_platform_init (void)
/* Avoid an empty string which would disturb us. */
GLRO(dl_platform) = NULL;
+#ifdef SHARED
+ /* init_cpu_features has been called early from __libc_start_main in
+ static executable. */
init_cpu_features (&GLRO(dl_x86_cpu_features));
+#endif
}
static inline ElfW(Addr)
--
2.5.5