From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org, stable@kernel.org
Cc: stable-review@kernel.org, torvalds@linux-foundation.org,
akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk
Subject: [patch 24/24] Dont use -fwrapv compiler option: its buggy in gcc-4.1.x
Date: Fri, 17 Jul 2009 13:09:15 -0700 [thread overview]
Message-ID: <20090717201238.142701426@mini.kroah.org> (raw)
In-Reply-To: <20090717201639.GA14209@kroah.com>
[-- Attachment #1: don-t-use-fwrapv-compiler-option-it-s-buggy-in-gcc-4.1.x.patch --]
[-- Type: text/plain, Size: 1582 bytes --]
2.6.30-stable review patch. If anyone has any objections, please let us know.
------------------
From: Linus Torvalds <torvalds@linux-foundation.org>
commit a137802ee839ace40079bebde24cfb416f73208a upstream.
This causes kernel images that don't run init to completion with certain
broken gcc versions.
This fixes kernel bugzilla entry:
http://bugzilla.kernel.org/show_bug.cgi?id=13012
I suspect the gcc problem is this:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28230
Fix the problem by using the -fno-strict-overflow flag instead, which
not only does not exist in the known-to-be-broken versions of gcc (it
was introduced later than fwrapv), but seems to be much less disturbing
to gcc too: the difference in the generated code by -fno-strict-overflow
are smaller (compared to using neither flag) than when using -fwrapv.
Reported-by: Barry K. Nathan <barryn@pobox.com>
Pushed-by: Frans Pop <elendil@planet.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/Makefile
+++ b/Makefile
@@ -574,7 +574,7 @@ KBUILD_CFLAGS += $(call cc-option,-Wdecl
KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,)
# disable invalid "can't wrap" optimizations for signed / pointers
-KBUILD_CFLAGS += $(call cc-option,-fwrapv)
+KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)
# revert to pre-gcc-4.4 behaviour of .eh_frame
KBUILD_CFLAGS += $(call cc-option,-fno-dwarf2-cfi-asm)
next prev parent reply other threads:[~2009-07-17 20:20 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20090717200851.907421303@mini.kroah.org>
2009-07-17 20:16 ` [patch 00/24] 2.6.30.2-stable review Greg KH
2009-07-17 20:08 ` [patch 01/24] Add -fno-delete-null-pointer-checks to gcc CFLAGS Greg KH
2009-07-17 20:08 ` [patch 02/24] security: use mmap_min_addr indepedently of security models Greg KH
2009-07-17 20:08 ` [patch 03/24] tun/tap: Fix crashes if open() /dev/net/tun and then poll() it. (CVE-2009-1897) Greg KH
2009-07-17 20:08 ` [patch 04/24] personality: fix PER_CLEAR_ON_SETID (CVE-2009-1895) Greg KH
2009-07-17 20:08 ` [patch 05/24] Blackfin: fix accidental reset in some boot modes Greg KH
2009-07-17 20:08 ` [patch 06/24] Blackfin: redo handling of bad irqs Greg KH
2009-07-17 20:08 ` [patch 07/24] Blackfin: fix deadlock in SMP IPI handler Greg KH
2009-07-17 20:08 ` [patch 08/24] Blackfin: fix command line corruption with DEBUG_DOUBLEFAULT Greg KH
2009-07-17 20:09 ` [patch 09/24] futex: Fix the write access fault problem for real Greg KH
2009-07-17 20:09 ` [patch 10/24] futexes: Fix infinite loop in get_futex_key() on huge page Greg KH
2009-07-17 20:09 ` [patch 11/24] kernel/resource.c: fix sign extension in reserve_setup() Greg KH
2009-07-17 20:09 ` [patch 12/24] alpha: fix percpu build breakage Greg KH
2009-07-17 20:09 ` [patch 13/24] dma-debug: fix off-by-one error in overlap function Greg KH
2009-07-17 20:09 ` [patch 14/24] blocK: Restore barrier support for md and probably other virtual devices Greg KH
2009-07-17 20:09 ` [patch 15/24] md/raid5: suspend shouldnt affect read requests Greg KH
2009-07-17 20:09 ` [patch 16/24] md: fix error path when duplicate name is found on md device creation Greg KH
2009-07-17 20:09 ` [patch 17/24] md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes Greg KH
2009-07-17 20:09 ` [patch 18/24] Revert "ipv4: arp announce, arp_proxy and windows ip conflict verification" Greg KH
2009-07-17 20:09 ` [patch 19/24] floppy: fix lock imbalance Greg KH
2009-07-17 20:09 ` [patch 20/24] Fix pci_unmap_addr() et al on i386 Greg KH
2009-07-17 20:09 ` [patch 21/24] Fix iommu address space allocation Greg KH
2009-07-17 20:09 ` [patch 22/24] fuse: fix bad return value in fuse_file_poll() Greg KH
2009-07-17 20:09 ` [patch 23/24] fuse: fix return value of fuse_dev_write() Greg KH
2009-07-17 20:09 ` Greg KH [this message]
2009-07-17 20:36 ` [patch 00/24] 2.6.30.2-stable review Greg KH
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