linux-kernel - Re: [PATCH 10/15] bugs/s390: Pass in 'cond_str' to __EMIT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250520133927.7932C19-hca@linux.ibm.com>
Date: Tue, 20 May 2025 15:39:27 +0200
From: Heiko Carstens <hca@...ux.ibm.com>
To: Ingo Molnar <mingo@...nel.org>
Cc: linux-kernel@...r.kernel.org,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Peter Zijlstra <peterz@...radead.org>, linux-arch@...r.kernel.org,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>,
        Sven Schnelle <svens@...ux.ibm.com>, linux-s390@...r.kernel.org
Subject: Re: [PATCH 10/15] bugs/s390: Pass in 'cond_str' to __EMIT_BUG()

On Thu, May 15, 2025 at 02:46:39PM +0200, Ingo Molnar wrote:
> Pass in the condition string from __WARN_FLAGS(), but do not
> concatenate it with __FILE__, because the __bug_table is
> apparently indexed by 16 bits and increasing string size
> overflows it on defconfig builds.

Could you provide your change which didn't work?

I cannot see how anything would overflow. Trying the below on top of
your series seems to work like expected.

In order to keep things easy this drops the mergeable section trick
and results in a small increase of the rodata section, but I doubt
that would explain what you have seen.

Also allyesconfig builds without errors.

diff --git a/arch/s390/include/asm/bug.h b/arch/s390/include/asm/bug.h
index 30f8785a01f5..837bfbde0c51 100644
--- a/arch/s390/include/asm/bug.h
+++ b/arch/s390/include/asm/bug.h
@@ -11,16 +11,14 @@
 #define __EMIT_BUG(cond_str, x) do {				\
 	asm_inline volatile(					\
 		"0:	mc	0,0\n"				\
-		".section .rodata.str,\"aMS\",@progbits,1\n"	\
-		"1:	.asciz	\""__FILE__"\"\n"		\
-		".previous\n"					\
 		".section __bug_table,\"aw\"\n"			\
-		"2:	.long	0b-.\n"				\
-		"	.long	1b-.\n"				\
-		"	.short	%0,%1\n"			\
-		"	.org	2b+%2\n"			\
+		"1:	.long	0b-.\n"				\
+		"	.long	%0-.\n"				\
+		"	.short	%1,%2\n"			\
+		"	.org	1b+%3\n"			\
 		".previous\n"					\
-		: : "i" (__LINE__),				\
+		: : "i" (WARN_CONDITION_STR(cond_str) __FILE__),\
+		    "i" (__LINE__),				\
 		    "i" (x),					\
 		    "i" (sizeof(struct bug_entry)));		\
 } while (0)