public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug c/36706] New: [Regression] linux-kernel 2.6.24 doesn't boot for arm @ 2008-07-02 22:34 chris dot steel dot lnx at googlemail dot com 2008-07-02 22:37 ` [Bug c/36706] " chris dot steel dot lnx at googlemail dot com ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: chris dot steel dot lnx at googlemail dot com @ 2008-07-02 22:34 UTC (permalink / raw) To: gcc-bugs I've built linux-2.6.24 for arm using gcc-4.3.1 and while it builds fine, the resulting binary doesn't boot on qemu. If I build the same kernel with gcc-4.2.4 it boots correctly. The problem seems to be that the prefetch function (linux-2.6.24/include/asm-arm/processor.h) causes a crash if it is called with a NULL pointer argument. But only if it's compiled with gcc-4.3.x. This patch fixes the problem, but the extra code may cost more than you gain by having prefetch in the first place diff -urN linux-2.6.24-clean/include/asm-arm/processor.h linux-2.6.24/include/asm-arm/processor.h --- linux-2.6.24-clean/include/asm-arm/processor.h 2008-01-24 22:58:37.000000000 +0000 +++ linux-2.6.24/include/asm-arm/processor.h 2008-07-02 22:44:26.052525328 +0100 @@ -105,11 +105,14 @@ #define ARCH_HAS_PREFETCH static inline void prefetch(const void *ptr) { - __asm__ __volatile__( - "pld\t%0" - : - : "o" (*(char *)ptr) - : "cc"); + if (ptr) + { + __asm__ __volatile__( + "pld\t%0" + : + : "o" (*(char *)ptr) + : "cc"); + } } #define ARCH_HAS_PREFETCHW -- Summary: [Regression] linux-kernel 2.6.24 doesn't boot for arm Product: gcc Version: 4.3.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: chris dot steel dot lnx at googlemail dot com GCC build triplet: x86_64-cross-linux-gnu GCC host triplet: x86_64-cross-linux-gnu GCC target triplet: arm-unknown-linux-gnueabi http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36706 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c/36706] [Regression] linux-kernel 2.6.24 doesn't boot for arm 2008-07-02 22:34 [Bug c/36706] New: [Regression] linux-kernel 2.6.24 doesn't boot for arm chris dot steel dot lnx at googlemail dot com @ 2008-07-02 22:37 ` chris dot steel dot lnx at googlemail dot com 2008-07-02 22:44 ` pinskia at gcc dot gnu dot org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: chris dot steel dot lnx at googlemail dot com @ 2008-07-02 22:37 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from chris dot steel dot lnx at googlemail dot com 2008-07-02 22:36 ------- Created an attachment (id=15845) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=15845&action=view) kernel config to reproduce the problem -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36706 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c/36706] [Regression] linux-kernel 2.6.24 doesn't boot for arm 2008-07-02 22:34 [Bug c/36706] New: [Regression] linux-kernel 2.6.24 doesn't boot for arm chris dot steel dot lnx at googlemail dot com 2008-07-02 22:37 ` [Bug c/36706] " chris dot steel dot lnx at googlemail dot com @ 2008-07-02 22:44 ` pinskia at gcc dot gnu dot org 2008-07-02 22:47 ` [Bug inline-asm/36706] " pinskia at gcc dot gnu dot org 2008-07-02 22:48 ` pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2008-07-02 22:44 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from pinskia at gcc dot gnu dot org 2008-07-02 22:44 ------- The use of "o" is most likely wrong here and most likely not a GCC issue as you are saying you access the memory when in reality you don't. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36706 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug inline-asm/36706] [Regression] linux-kernel 2.6.24 doesn't boot for arm 2008-07-02 22:34 [Bug c/36706] New: [Regression] linux-kernel 2.6.24 doesn't boot for arm chris dot steel dot lnx at googlemail dot com 2008-07-02 22:37 ` [Bug c/36706] " chris dot steel dot lnx at googlemail dot com 2008-07-02 22:44 ` pinskia at gcc dot gnu dot org @ 2008-07-02 22:47 ` pinskia at gcc dot gnu dot org 2008-07-02 22:48 ` pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2008-07-02 22:47 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from pinskia at gcc dot gnu dot org 2008-07-02 22:46 ------- Yes o is wrong here. THis is not a GCC bug. -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |INVALID http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36706 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug inline-asm/36706] [Regression] linux-kernel 2.6.24 doesn't boot for arm 2008-07-02 22:34 [Bug c/36706] New: [Regression] linux-kernel 2.6.24 doesn't boot for arm chris dot steel dot lnx at googlemail dot com ` (2 preceding siblings ...) 2008-07-02 22:47 ` [Bug inline-asm/36706] " pinskia at gcc dot gnu dot org @ 2008-07-02 22:48 ` pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu dot org @ 2008-07-02 22:48 UTC (permalink / raw) To: gcc-bugs ------- Comment #4 from pinskia at gcc dot gnu dot org 2008-07-02 22:47 ------- "o" means any offsetable memory operand so GCC thinks you are accessing memory that will always be valid. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36706 ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2008-07-02 22:48 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2008-07-02 22:34 [Bug c/36706] New: [Regression] linux-kernel 2.6.24 doesn't boot for arm chris dot steel dot lnx at googlemail dot com 2008-07-02 22:37 ` [Bug c/36706] " chris dot steel dot lnx at googlemail dot com 2008-07-02 22:44 ` pinskia at gcc dot gnu dot org 2008-07-02 22:47 ` [Bug inline-asm/36706] " pinskia at gcc dot gnu dot org 2008-07-02 22:48 ` pinskia at gcc dot gnu dot org
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).