Red Hat Bugzilla – Bug 484871
linux-2.6-misc-utrace-update.patch contains incorrect optimization
Last modified: 2009-03-02 11:56:44 EST
+++ This bug was initially created as a clone of Bug #481682 +++
Created an attachment (id=330051)
in kernel-2.6.18-128.el5 and prior versions, arch/x86_64/ia32/ia32entry.S hunk of the linux-2.6-misc-utrace-update.patch contains incorrect optimization.
As result, out-of-table 32-bit syscalls on the x86_64 kernel do not return ENOSYS (unless the caller is being ptraced).
For example, glibc-2.9+ popen() goes mad when pipe2 syscall returns its number 331 instead of fail with ENOSYS.
As result, FC10+ 32-bit processes on RHEL5 x86_64 kernel break once popen(3) is called.
--- Additional comment from email@example.com on 2009-01-27 04:29:59 EDT ---
The issue was found while running Fedora 10 containers on an RHEL5+OpenVZ kernel.
Relative OpenVZ bug: http://bugzilla.openvz.org/show_bug.cgi?id=1150
--- Additional comment from firstname.lastname@example.org on 2009-02-06 20:59:52 EDT ---
Created an attachment (id=331182)
test case source
Simple test case, compile with -m32 and run on x86-64 kernel.
The RHEL5 code is the same (broken) as upstream. I'll fix it upstream and then RHEL5 should backport the change so it continues to match upstream.
--- Additional comment from email@example.com on 2009-02-06 21:02:48 EDT ---
Created an attachment (id=331183)
test case source
Test case fixed to exit 0 for correct and nonzero for bug.
Also, I forgot to note that to reproduce you have to have auditd disabled:
/sbin/chkconfig auditd off; reboot
--- Additional comment from firstname.lastname@example.org on 2009-02-06 21:34:13 EDT ---
Created an attachment (id=331187)
fix posted upstream
Wait to see if upstream takes this as is, but almost certain they will.
With s,/x86/,/x86_64/,g this same patch applies to RHEL5 fine.
--- Additional comment from email@example.com on 2009-02-07 04:57:47 EDT ---
> The RHEL5 code is the same (broken) as upstream.
RHEL5 is not broken, I wasn't able to reproduce it. As I understood, this is due to this check:
And we have TIF_SYSCALL_AUDIT set.
Also, it's possible to make the patch shorter:
@@ -417,6 +417,7 @@ ENTRY(ia32_syscall)
+ movq $-ENOSYS,RAX-ARGOFFSET(%rsp)
I've tested it yesterday, but didn't post upstream yet.
--- Additional comment from firstname.lastname@example.org on 2009-02-07 17:21:41 EDT ---
It is broken. See comment#3 on how to reproduce it.
Shorter patch does not mean shorter code path, which is what matters.
Anyway, I've already posted upstream.
--- Additional comment from email@example.com on 2009-02-07 17:25:55 EDT ---
Upstream fix was merged: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c09249f8d1b84344eca882547afdbffee8c09d14
I don't know what the point of this bug report is. The fix is already in upstream, and rawhide rebases from upstream daily.
I think you want to file this bug against Fedora 10 ??
(In reply to comment #2)
> I think you want to file this bug against Fedora 10 ??
Yes. I don't know if this will be backported to 2.6.27.x
Fixed in 126.96.36.199-170.2.28 and will send to -stable.
kernel-188.8.131.52-170.2.35.fc10 has been pushed to the Fedora 10 testing repository. If problems still persist, please make note of it in this bug report.
If you want to test the update, you can install it with
su -c 'yum --enablerepo=updates-testing update kernel'. You can provide feedback for this update here: http://admin.fedoraproject.org/updates/F10/FEDORA-2009-2003
kernel-184.108.40.206-170.2.35.fc10 has been pushed to the Fedora 10 stable repository. If problems still persist, please make note of it in this bug report.