lkml.org 
[lkml]   [2017]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [tip:core/urgent] objtool: Fix __unreachable section relocation size
From
On March 1, 2017 12:10:59 AM PST, tip-bot for Josh Poimboeuf <tipbot@zytor.com> wrote:
>Commit-ID: 90a7e63a31b8f7d630d12ef0d8d37d3ab87f76e5
>Gitweb:
>http://git.kernel.org/tip/90a7e63a31b8f7d630d12ef0d8d37d3ab87f76e5
>Author: Josh Poimboeuf <jpoimboe@redhat.com>
>AuthorDate: Wed, 1 Mar 2017 00:05:04 -0600
>Committer: Ingo Molnar <mingo@kernel.org>
>CommitDate: Wed, 1 Mar 2017 07:38:25 +0100
>
>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.
>
>Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
>Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
>Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
>Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
>Cc: Peter Zijlstra <peterz@infradead.org>
>Cc: Thomas Gleixner <tglx@linutronix.de>
>Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other
>dead ends")
>Link: http://lkml.kernel.org/r/20170301060504.oltm3iws6fmubnom@treble
>Signed-off-by: Ingo Molnar <mingo@kernel.org>
>---
> 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

Or perhaps better use relative addresses, so:

.long foo - (.+4)


--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

\
 
 \ /
  Last update: 2017-03-01 09:44    [W:0.084 / U:0.072 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site