Fix for objtool/module breakage
This commit is contained in:
Laura Abbott
parent
3a9b20b346
commit
e582bbd727
@ -602,6 +602,9 @@ Patch666: ccm-stack.patch
|
|||||||
# grabbed from mailing list
|
# grabbed from mailing list
|
||||||
Patch667: v3-Revert-tty-serial-pl011-add-ttyAMA-for-matching-pl011-console.patch
|
Patch667: v3-Revert-tty-serial-pl011-add-ttyAMA-for-matching-pl011-console.patch
|
||||||
|
|
||||||
|
# reported via IRC
|
||||||
|
Patch668: objtool-fix.patch
|
||||||
|
|
||||||
# END OF PATCH DEFINITIONS
|
# END OF PATCH DEFINITIONS
|
||||||
|
|
||||||
%endif
|
%endif
|
||||||
|
|||||||
153
objtool-fix.patch
Normal file
153
objtool-fix.patch
Normal file
@ -0,0 +1,153 @@
|
|||||||
|
From 898d20ca04d5a13dcca5483ed5213ad92fed88d3 Mon Sep 17 00:00:00 2001
|
||||||
|
From: Josh Poimboeuf <jpoimboe@redhat.com>
|
||||||
|
Date: Wed, 1 Mar 2017 00:05:04 -0600
|
||||||
|
Subject: [PATCH] objtool fixes
|
||||||
|
|
||||||
|
On Tue, Feb 28, 2017 at 05:55:11PM -0800, Linus Torvalds wrote:
|
||||||
|
> Guys,
|
||||||
|
> the recent 'objtool' pull request broke things.
|
||||||
|
>
|
||||||
|
> I haven't bisected it, but I'm pretty sure that this part is pure garbage:
|
||||||
|
>
|
||||||
|
> On Mon, Feb 27, 2017 at 11:53 PM, Ingo Molnar <mingo@kernel.org> wrote:
|
||||||
|
> >
|
||||||
|
> > diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
|
||||||
|
> > index e79f15f108a8..ad0118fbce90 100644
|
||||||
|
> > --- a/arch/x86/kernel/vmlinux.lds.S
|
||||||
|
> > +++ b/arch/x86/kernel/vmlinux.lds.S
|
||||||
|
> > @@ -346,6 +346,7 @@ SECTIONS
|
||||||
|
> > /DISCARD/ : {
|
||||||
|
> > *(.eh_frame)
|
||||||
|
> > *(__func_stack_frame_non_standard)
|
||||||
|
> > + *(__unreachable)
|
||||||
|
> > }
|
||||||
|
> > }
|
||||||
|
> >
|
||||||
|
> > diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
|
||||||
|
> > index 0444b1336268..f457b520ead6 100644
|
||||||
|
> > --- a/include/linux/compiler-gcc.h
|
||||||
|
> > +++ b/include/linux/compiler-gcc.h
|
||||||
|
> > @@ -195,6 +195,17 @@
|
||||||
|
> > #endif
|
||||||
|
> > #endif
|
||||||
|
> >
|
||||||
|
> > +#ifdef CONFIG_STACK_VALIDATION
|
||||||
|
> > +#define annotate_unreachable() ({ \
|
||||||
|
> > + asm("%c0:\t\n" \
|
||||||
|
> > + ".pushsection __unreachable, \"a\"\t\n" \
|
||||||
|
> > + ".long %c0b\t\n" \
|
||||||
|
> > + ".popsection\t\n" : : "i" (__LINE__)); \
|
||||||
|
> > +})
|
||||||
|
> > +#else
|
||||||
|
> > +#define annotate_unreachable()
|
||||||
|
> > +#endif
|
||||||
|
>
|
||||||
|
> and I think the above is what breaks module loading for me right now
|
||||||
|
> on my laptop.
|
||||||
|
>
|
||||||
|
> I get this during bootup:
|
||||||
|
>
|
||||||
|
> module: overflow in relocation type 10 val ffffffffc02afc81
|
||||||
|
> module: 'nvme' likely not compiled with -mcmodel=kernel
|
||||||
|
>
|
||||||
|
> (and similar errors for other modules too), but those modules very
|
||||||
|
> much *are* compiled with all the normal kernel build flags, including
|
||||||
|
> -mcmodel=kernel.
|
||||||
|
>
|
||||||
|
> Now, relocation type 10 is R_X86_64_32, so the warning is very true:
|
||||||
|
> that address would fit in a _signed_ 32-bit value, but that's
|
||||||
|
> supposedly a 32-bit unsigned relocation.
|
||||||
|
>
|
||||||
|
> Trying to figure out what the hell is going on, I do:
|
||||||
|
>
|
||||||
|
> objdump -r nvme.ko | grep 64_32
|
||||||
|
>
|
||||||
|
> and what do I find? I find
|
||||||
|
>
|
||||||
|
> RELOCATION RECORDS FOR [__unreachable]:
|
||||||
|
> OFFSET TYPE VALUE
|
||||||
|
> 0000000000000000 R_X86_64_32 .text+0x0000000000000c81
|
||||||
|
> 0000000000000004 R_X86_64_32 .text+0x0000000000000cb5
|
||||||
|
> 0000000000000008 R_X86_64_32 .text+0x0000000000001a18
|
||||||
|
> 000000000000000c R_X86_64_32 .text+0x0000000000001a36
|
||||||
|
> 0000000000000010 R_X86_64_32 .text+0x0000000000001e38
|
||||||
|
> 0000000000000014 R_X86_64_32 .text+0x0000000000001ec2
|
||||||
|
> 0000000000000018 R_X86_64_32 .text+0x00000000000034e2
|
||||||
|
> 000000000000001c R_X86_64_32 .text+0x0000000000003536
|
||||||
|
>
|
||||||
|
> and then when I look more closely (objdump --disassemble), I see that
|
||||||
|
> the offset 000c81 in the module refers to this:
|
||||||
|
>
|
||||||
|
> 0000000000000c60 <nvme_admin_init_request>:
|
||||||
|
> ....
|
||||||
|
> c7f: 0f 0b ud2
|
||||||
|
> c81: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
|
||||||
|
>
|
||||||
|
> so it very much looks like those relocations are still around on
|
||||||
|
> modules, and so module loading fails.
|
||||||
|
>
|
||||||
|
> Anyway, those annotations are completely bogus anyway, it looks. You
|
||||||
|
> guys should use relative offsets in order to be able to specify a
|
||||||
|
> kernel address. So doing
|
||||||
|
>
|
||||||
|
> .long %c0
|
||||||
|
>
|
||||||
|
> is garbage - either it needs to be a .quad, or it needs to be relative
|
||||||
|
> to the text section to fit in a .long.
|
||||||
|
>
|
||||||
|
> Hmm? Revert or fix, but please quickly...
|
||||||
|
|
||||||
|
Yuck, sorry about that. Patch to fix it below.
|
||||||
|
|
||||||
|
This also highlights another (minor) issue: the '__unreachable' section
|
||||||
|
is meant to be a compile-time-only thing. It's supposed to be discarded
|
||||||
|
at link time, but apparently that isn't happening for modules.
|
||||||
|
|
||||||
|
I tried excluding it from linking with the .pushsection "e" flag, but no
|
||||||
|
luck. I'll try to figure out how to fix that shortly.
|
||||||
|
|
||||||
|
In the meantime, here's the fix you need. It now uses X86_64_64
|
||||||
|
relocations.
|
||||||
|
|
||||||
|
----
|
||||||
|
|
||||||
|
From: Josh Poimboeuf <jpoimboe@redhat.com>
|
||||||
|
Subject: [PATCH] objtool: fix __unreachable section relocation size
|
||||||
|
|
||||||
|
Linus reported the following commit broke module loading on his laptop:
|
||||||
|
|
||||||
|
d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")
|
||||||
|
|
||||||
|
It showed errors like the following:
|
||||||
|
|
||||||
|
module: overflow in relocation type 10 val ffffffffc02afc81
|
||||||
|
module: 'nvme' likely not compiled with -mcmodel=kernel
|
||||||
|
|
||||||
|
The problem is that the __unreachable section addresses are stored using
|
||||||
|
the '.long' asm directive, which isn't big enough for .text section
|
||||||
|
relative kernel addresses. Use '.quad' instead.
|
||||||
|
|
||||||
|
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||||||
|
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||||||
|
Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends")
|
||||||
|
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
|
||||||
|
---
|
||||||
|
include/linux/compiler-gcc.h | 2 +-
|
||||||
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
||||||
|
|
||||||
|
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
|
||||||
|
index 76e28c2..91a77a5 100644
|
||||||
|
--- a/include/linux/compiler-gcc.h
|
||||||
|
+++ b/include/linux/compiler-gcc.h
|
||||||
|
@@ -201,7 +201,7 @@
|
||||||
|
#define annotate_unreachable() ({ \
|
||||||
|
asm("%c0:\t\n" \
|
||||||
|
".pushsection __unreachable, \"a\"\t\n" \
|
||||||
|
- ".long %c0b\t\n" \
|
||||||
|
+ ".quad %c0b\t\n" \
|
||||||
|
".popsection\t\n" : : "i" (__LINE__)); \
|
||||||
|
})
|
||||||
|
#else
|
||||||
|
--
|
||||||
|
2.7.4
|
||||||
|
|
||||||
Loading…
Reference in New Issue
Block a user