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* [Bug c/28281] New: gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode
@ 2006-07-06 9:23 arjan at linux dot intel dot com
2006-07-06 9:24 ` [Bug c/28281] " arjan at linux dot intel dot com
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: arjan at linux dot intel dot com @ 2006-07-06 9:23 UTC (permalink / raw)
To: gcc-bugs
Userspace and kernel space use a different segment register for TLS access in
x86_64. (This is so that a syscall doesn't need to switch these registers most
of the time, so good for performance)
This means that the kernel cannot use -fstack-protector currently, which is sad
since today another buffer overflow has been found in the linux kernel.
The solution is quite simple, and I will attach a patch to fix this next; just
use a different segement register for the mc_kernel model.
(the patch is trivial; it copies a line and changes a few characters in it, and
then places an if around it)
--
Summary: gcc uses the wrong segment register for TLS access for -
fstack-protector in kernel mode
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: arjan at linux dot intel dot com
GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28281
^ permalink raw reply [flat|nested] 7+ messages in thread* [Bug c/28281] gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode 2006-07-06 9:23 [Bug c/28281] New: gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode arjan at linux dot intel dot com @ 2006-07-06 9:24 ` arjan at linux dot intel dot com 2006-07-06 9:49 ` arjan at linux dot intel dot com ` (4 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: arjan at linux dot intel dot com @ 2006-07-06 9:24 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from arjan at linux dot intel dot com 2006-07-06 09:24 ------- Created an attachment (id=11839) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11839&action=view) patch to fix this issue, including a testcase patch + testcase for this issue 2006-07-06 Arjan van de Ven <arjan@linux.intel.com> * config/i386/i386.md: add conditonal for kernel side stack-protector -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28281 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/28281] gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode 2006-07-06 9:23 [Bug c/28281] New: gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode arjan at linux dot intel dot com 2006-07-06 9:24 ` [Bug c/28281] " arjan at linux dot intel dot com @ 2006-07-06 9:49 ` arjan at linux dot intel dot com 2006-07-06 11:09 ` arjan at linux dot intel dot com ` (3 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: arjan at linux dot intel dot com @ 2006-07-06 9:49 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from arjan at linux dot intel dot com 2006-07-06 09:49 ------- Created an attachment (id=11842) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11842&action=view) updated patch updated patch; it helps if I send the non-test version of the testsuite test so that it actually tests the right behavior -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28281 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/28281] gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode 2006-07-06 9:23 [Bug c/28281] New: gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode arjan at linux dot intel dot com 2006-07-06 9:24 ` [Bug c/28281] " arjan at linux dot intel dot com 2006-07-06 9:49 ` arjan at linux dot intel dot com @ 2006-07-06 11:09 ` arjan at linux dot intel dot com 2006-07-06 14:53 ` [Bug target/28281] " pinskia at gcc dot gnu dot org ` (2 subsequent siblings) 5 siblings, 0 replies; 7+ messages in thread From: arjan at linux dot intel dot com @ 2006-07-06 11:09 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from arjan at linux dot intel dot com 2006-07-06 11:08 ------- Created an attachment (id=11844) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11844&action=view) updates with Jakub's comments updates with jakubs comments -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28281 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/28281] gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode 2006-07-06 9:23 [Bug c/28281] New: gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode arjan at linux dot intel dot com ` (2 preceding siblings ...) 2006-07-06 11:09 ` arjan at linux dot intel dot com @ 2006-07-06 14:53 ` pinskia at gcc dot gnu dot org 2006-07-29 7:46 ` arjan at linux dot intel dot com 2006-07-29 7:47 ` belyshev at depni dot sinp dot msu dot ru 5 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu dot org @ 2006-07-06 14:53 UTC (permalink / raw) To: gcc-bugs -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Severity|normal |enhancement Component|c |target http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28281 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/28281] gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode 2006-07-06 9:23 [Bug c/28281] New: gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode arjan at linux dot intel dot com ` (3 preceding siblings ...) 2006-07-06 14:53 ` [Bug target/28281] " pinskia at gcc dot gnu dot org @ 2006-07-29 7:46 ` arjan at linux dot intel dot com 2006-07-29 7:47 ` belyshev at depni dot sinp dot msu dot ru 5 siblings, 0 replies; 7+ messages in thread From: arjan at linux dot intel dot com @ 2006-07-29 7:46 UTC (permalink / raw) To: gcc-bugs ------- Comment #4 from arjan at linux dot intel dot com 2006-07-29 07:46 ------- fixed in current SVN -- arjan at linux dot intel dot com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution| |FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28281 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug target/28281] gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode 2006-07-06 9:23 [Bug c/28281] New: gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode arjan at linux dot intel dot com ` (4 preceding siblings ...) 2006-07-29 7:46 ` arjan at linux dot intel dot com @ 2006-07-29 7:47 ` belyshev at depni dot sinp dot msu dot ru 5 siblings, 0 replies; 7+ messages in thread From: belyshev at depni dot sinp dot msu dot ru @ 2006-07-29 7:47 UTC (permalink / raw) To: gcc-bugs -- belyshev at depni dot sinp dot msu dot ru changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |4.2.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28281 ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2006-07-29 7:47 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2006-07-06 9:23 [Bug c/28281] New: gcc uses the wrong segment register for TLS access for -fstack-protector in kernel mode arjan at linux dot intel dot com 2006-07-06 9:24 ` [Bug c/28281] " arjan at linux dot intel dot com 2006-07-06 9:49 ` arjan at linux dot intel dot com 2006-07-06 11:09 ` arjan at linux dot intel dot com 2006-07-06 14:53 ` [Bug target/28281] " pinskia at gcc dot gnu dot org 2006-07-29 7:46 ` arjan at linux dot intel dot com 2006-07-29 7:47 ` belyshev at depni dot sinp dot msu dot ru
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