* Move Linux kernel version conditionals to kernel-features.h
@ 2012-08-03 15:07 Joseph S. Myers
2012-08-03 18:38 ` Roland McGrath
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Joseph S. Myers @ 2012-08-03 15:07 UTC (permalink / raw)
To: libc-alpha; +Cc: libc-ports, Mike Frysinger
Generally conditions on the compile-time minimum Linux kernel version
go via __ASSUME_* macros defined in kernel-features.h. However,
sysdeps/unix/sysv/linux/sysconf.c and
ports/sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h have such
conditions directly using __LINUX_KERNEL_VERSION.
This patch fixes those conditions to follow the kernel-features.h
convention instead. For sysconf.c, a new macro
__ASSUME_ARG_MAX_STACK_BASED is defined and used. Because the #if
condition was a condition on an if () condition using the same
version, the same version number was previously repeated in both
conditions in close proximity; to avoid those copies (that should be
in sync) now being widely separated, I defined a macro
__LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL for the version number in
question. For ports/sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h, I
removed the condition; this is in line with commit
de7f5ce7c595f4741029f7e63429826f8e82b340 which removed such a
condition from nptl/sysdeps/unix/sysv/linux/i386/i686/dl-sysdep.h a
few months ago.
Tested x86_64. (This should be reviewed for ia64.)
2012-08-03 Joseph Myers <joseph@codesourcery.com>
* sysdeps/unix/sysv/linux/kernel-features.h
(__LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL): Define.
[__LINUX_KERNEL_VERSION >= __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL]
(__ASSUME_ARG_MAX_STACK_BASED): Define.
* sysdeps/unix/sysv/linux/sysconf.c (__sysconf)
[__LINUX_KERNEL_VERSION < 0x020617]: Change condition to
!__ASSUME_ARG_MAX_STACK_BASED. Compare version with
__LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL.
ports/ChangeLog.ia64
2012-08-03 Joseph Myers <joseph@codesourcery.com>
* sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h
(_dl_discover_osversion): Do not condition on
__LINUX_KERNEL_VERSION < 0x020617.
(HAVE_DL_DISCOVER_OSVERSION): Likewise.
diff --git a/ports/sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h b/ports/sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h
index e30e33d..0962129 100644
--- a/ports/sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h
+++ b/ports/sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h
@@ -1,5 +1,5 @@
/* System-specific settings for dynamic linker code. IA-64 version.
- Copyright (C) 2003, 2004, 2006, 2008 Free Software Foundation, Inc.
+ Copyright (C) 2003-2012 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
@@ -65,9 +65,7 @@ extern int _dl_sysinfo_break attribute_hidden;
#define DL_ARGV_NOT_RELRO 1
-/* The _dl_discover_osversion function is so far only needed in sysconf
- to check for kernels later than 2.6.23. */
-#if !defined __ASSEMBLER__ && __LINUX_KERNEL_VERSION < 0x020617
+#ifndef __ASSEMBLER__
/* Get version of the OS. */
extern int _dl_discover_osversion (void) attribute_hidden;
# define HAVE_DL_DISCOVER_OSVERSION 1
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index b949f16..18cb038 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -279,6 +279,13 @@
# define __ASSUME_O_CLOEXEC 1
#endif
+/* From 2.6.23 onwards the value of ARG_MAX depends on the stack
+ size. */
+#define __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL 0x020617
+#if __LINUX_KERNEL_VERSION >= __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL
+# define __ASSUME_ARG_MAX_STACK_BASED 1
+#endif
+
/* Support for ADJ_OFFSET_SS_READ was added in 2.6.24. */
#if __LINUX_KERNEL_VERSION >= 0x020618
# define __ASSUME_ADJ_OFFSET_SS_READ 1
diff --git a/sysdeps/unix/sysv/linux/sysconf.c b/sysdeps/unix/sysv/linux/sysconf.c
index 5c8f45d..47ce5ef 100644
--- a/sysdeps/unix/sysv/linux/sysconf.c
+++ b/sysdeps/unix/sysv/linux/sysconf.c
@@ -1,5 +1,5 @@
/* Get file-specific information about a file. Linux version.
- Copyright (C) 2003,2004,2006 2008,2009,2011 Free Software Foundation, Inc.
+ Copyright (C) 2003-2012 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
@@ -88,11 +88,11 @@ __sysconf (int name)
return HAS_CPUCLOCK (name);
case _SC_ARG_MAX:
-#if __LINUX_KERNEL_VERSION < 0x020617
- /* Determine whether this is a kernel 2.6.23 or later. Only
- then do we have an argument limit determined by the stack
- size. */
- if (GLRO(dl_discover_osversion) () >= 0x020617)
+#if !__ASSUME_ARG_MAX_STACK_BASED
+ /* Determine whether this is a kernel with an argument limit
+ determined by the stack size. */
+ if (GLRO(dl_discover_osversion) ()
+ >= __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL)
#endif
/* Use getrlimit to get the stack limit. */
if (__getrlimit (RLIMIT_STACK, &rlimit) == 0)
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Move Linux kernel version conditionals to kernel-features.h
2012-08-03 15:07 Move Linux kernel version conditionals to kernel-features.h Joseph S. Myers
@ 2012-08-03 18:38 ` Roland McGrath
2012-08-09 23:37 ` Ping ia64 " Joseph S. Myers
2012-08-10 15:49 ` Mike Frysinger
2 siblings, 0 replies; 4+ messages in thread
From: Roland McGrath @ 2012-08-03 18:38 UTC (permalink / raw)
To: Joseph S. Myers; +Cc: libc-alpha, libc-ports, Mike Frysinger
Looks fine.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Ping ia64 Re: Move Linux kernel version conditionals to kernel-features.h
2012-08-03 15:07 Move Linux kernel version conditionals to kernel-features.h Joseph S. Myers
2012-08-03 18:38 ` Roland McGrath
@ 2012-08-09 23:37 ` Joseph S. Myers
2012-08-10 15:49 ` Mike Frysinger
2 siblings, 0 replies; 4+ messages in thread
From: Joseph S. Myers @ 2012-08-09 23:37 UTC (permalink / raw)
To: libc-ports; +Cc: Mike Frysinger
On Fri, 3 Aug 2012, Joseph S. Myers wrote:
> Generally conditions on the compile-time minimum Linux kernel version
> go via __ASSUME_* macros defined in kernel-features.h. However,
> sysdeps/unix/sysv/linux/sysconf.c and
> ports/sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h have such
> conditions directly using __LINUX_KERNEL_VERSION.
>
> This patch fixes those conditions to follow the kernel-features.h
> convention instead. For sysconf.c, a new macro
> __ASSUME_ARG_MAX_STACK_BASED is defined and used. Because the #if
> condition was a condition on an if () condition using the same
> version, the same version number was previously repeated in both
> conditions in close proximity; to avoid those copies (that should be
> in sync) now being widely separated, I defined a macro
> __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL for the version number in
> question. For ports/sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h, I
> removed the condition; this is in line with commit
> de7f5ce7c595f4741029f7e63429826f8e82b340 which removed such a
> condition from nptl/sysdeps/unix/sysv/linux/i386/i686/dl-sysdep.h a
> few months ago.
>
> Tested x86_64. (This should be reviewed for ia64.)
Ping. This patch
<http://sourceware.org/ml/libc-ports/2012-08/msg00028.html> is pending
ia64 review.
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Move Linux kernel version conditionals to kernel-features.h
2012-08-03 15:07 Move Linux kernel version conditionals to kernel-features.h Joseph S. Myers
2012-08-03 18:38 ` Roland McGrath
2012-08-09 23:37 ` Ping ia64 " Joseph S. Myers
@ 2012-08-10 15:49 ` Mike Frysinger
2 siblings, 0 replies; 4+ messages in thread
From: Mike Frysinger @ 2012-08-10 15:49 UTC (permalink / raw)
To: Joseph S. Myers; +Cc: libc-alpha, libc-ports
[-- Attachment #1: Type: Text/Plain, Size: 381 bytes --]
On Friday 03 August 2012 11:06:51 Joseph S. Myers wrote:
> ports/ChangeLog.ia64
> 2012-08-03 Joseph Myers <joseph@codesourcery.com>
>
> * sysdeps/unix/sysv/linux/ia64/nptl/dl-sysdep.h
> (_dl_discover_osversion): Do not condition on
> __LINUX_KERNEL_VERSION < 0x020617.
> (HAVE_DL_DISCOVER_OSVERSION): Likewise.
Acked-by: Mike Frysinger <vapier@gentoo.org>
-mike
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^ permalink raw reply [flat|nested] 4+ messages in thread
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2012-08-03 15:07 Move Linux kernel version conditionals to kernel-features.h Joseph S. Myers
2012-08-03 18:38 ` Roland McGrath
2012-08-09 23:37 ` Ping ia64 " Joseph S. Myers
2012-08-10 15:49 ` Mike Frysinger
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