Patch "debug: Fix WARN_ON_ONCE() for modules" has been added to the 4.12-stable tree
Subsystems (8)
This is a note to let you know that I've just added the patch titled
debug: Fix WARN_ON_ONCE() for modules
to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
debug-fix-warn_on_once-for-modules.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From
325cdacd03c12629aa5f9ee2ace49b1f3dc184a8Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <[email protected]>
Date: Sat, 15 Jul 2017 00:10:58 -0500
Subject: debug: Fix WARN_ON_ONCE() for modules
From: Josh Poimboeuf <[email protected]>
commit 325cdacd03c12629aa5f9ee2ace49b1f3dc184a8 upstream.
Mike Galbraith reported a situation where a WARN_ON_ONCE() call in DRM code turned into an oops. As it turns out, WARN_ON_ONCE() seems to be completely broken when called from a module.
The bug was introduced with the following commit:
19d436268dde ("debug: Add _ONCE() logic to report_bug()")
That commit changed WARN_ON_ONCE() to move its 'once' logic into the bug trap handler. It requires a writable bug table so that the BUGFLAG_DONE bit can be written to the flags to indicate the first warning has occurred.
The bug table was made writable for vmlinux, which relies on vmlinux.lds.S and vmlinux.lds.h for laying out the sections. However, it wasn't made writable for modules, which rely on the ELF section header flags.
--- arch/arm/include/asm/bug.h | 2 +- arch/arm64/include/asm/bug.h | 2 +- arch/blackfin/include/asm/bug.h | 4 ++-- arch/mn10300/include/asm/bug.h | 2 +- arch/parisc/include/asm/bug.h | 6 +++--- arch/powerpc/include/asm/bug.h | 8 ++++---- arch/s390/include/asm/bug.h | 4 ++-- arch/sh/include/asm/bug.h | 4 ++-- arch/x86/include/asm/bug.h | 4 ++-- 9 files changed, 18 insertions(+), 18 deletions(-)
arch/arm/include/asm/bug.h +1 -1
@@ -37,7 +37,7 @@ do { \".pushsection .rodata.str, \"aMS\", %progbits, 1\n" \ "2:\t.asciz " #__file "\n" \".popsection\n" \ -".pushsection __bug_table,\"a\"\n" \ +".pushsection __bug_table,\"aw\"\n" \".align 2\n" \"3:\t.word 1b, 2b\n" \ "\t.hword " #__line ", 0\n" \
arch/arm64/include/asm/bug.h +1 -1
@@ -36,7 +36,7 @@#ifdef CONFIG_GENERIC_BUG #define __BUG_ENTRY (flags) \ - ".pushsection __bug_table,\"a\"\n\t" \ + ".pushsection __bug_table,\"aw\"\n\t" \ ".align 2\n\t" \ "0: .long 1f - 0b\n\t" \ _BUGVERBOSE_LOCATION(__FILE__, __LINE__) \
arch/blackfin/include/asm/bug.h +2 -2
@@ -21,7 +21,7 @@#define _BUG_OR_WARN (flags) \ asm volatile( \ "1: .hword %0\n" \ - " .section __bug_table,\"a\",@progbits\n" \ + " .section __bug_table,\"aw\",@progbits\n" \ "2: .long 1b\n" \ " .long %1\n" \ " .short %2\n" \
@@ -38,7 +38,7 @@#define _BUG_OR_WARN (flags) \ asm volatile( \ "1: .hword %0\n" \ - " .section __bug_table,\"a\",@progbits\n" \ + " .section __bug_table,\"aw\",@progbits\n" \ "2: .long 1b\n" \ " .short %1\n" \ " .org 2b + %2\n" \
arch/mn10300/include/asm/bug.h +1 -1
@@ -21,7 +21,7 @@ do { \ asmvolatile ( \" syscall 15 \n" \"0: \n" \ -" .section __bug_table,\"a\" \n" \ +" .section __bug_table,\"aw\" \n" \" .long 0b,%0,%1 \n" \" .previous \n" \ : \
arch/parisc/include/asm/bug.h +3 -3
@@ -27,7 +27,7 @@ do { \ asm volatile("\n" \ "1:\t" PARISC_BUG_BREAK_ASM "\n" \ - "\t.pushsection __bug_table,\"a\"\n" \ + "\t.pushsection __bug_table,\"aw\"\n" \ "2:\t" ASM_WORD_INSN "1b, %c0\n" \ "\t.short %c1, %c2\n" \ "\t.org 2b+%c3\n" \
@@ -50,7 +50,7 @@ do { \ asm volatile("\n" \ "1:\t" PARISC_BUG_BREAK_ASM "\n" \ - "\t.pushsection __bug_table,\"a\"\n" \ + "\t.pushsection __bug_table,\"aw\"\n" \ "2:\t" ASM_WORD_INSN "1b, %c0\n" \ "\t.short %c1, %c2\n" \ "\t.org 2b+%c3\n" \
@@ -64,7 +64,7 @@ do { \ asm volatile("\n" \ "1:\t" PARISC_BUG_BREAK_ASM "\n" \ - "\t.pushsection __bug_table,\"a\"\n" \ + "\t.pushsection __bug_table,\"aw\"\n" \ "2:\t" ASM_WORD_INSN "1b\n" \ "\t.short %c0\n" \ "\t.org 2b+%c1\n" \
arch/powerpc/include/asm/bug.h +4 -4
@@ -18,7 +18,7 @@#include <asm/asm-offsets.h> #ifdef CONFIG_DEBUG_BUGVERBOSE .macro EMIT_BUG_ENTRY addr,file,line,flags - .section __bug_table,"a" + .section __bug_table,"aw" 5001: PPC_LONG \addr, 5002f .short \line, \flags .org 5001b+BUG_ENTRY_SIZE
@@ -29,7 +29,7 @@ .endm #else .macro EMIT_BUG_ENTRY addr,file,line,flags - .section __bug_table,"a" + .section __bug_table,"aw" 5001: PPC_LONG \addr .short \flags .org 5001b+BUG_ENTRY_SIZE
@@ -42,14 +42,14 @@sizeof(struct bug_entry), respectively */ #ifdef CONFIG_DEBUG_BUGVERBOSE #define _EMIT_BUG_ENTRY \ - ".section __bug_table,\"a\"\n" \ + ".section __bug_table,\"aw\"\n" \ "2:\t" PPC_LONG "1b, %0\n" \ "\t.short %1, %2\n" \ ".org 2b+%3\n" \ ".previous\n"#else #define _EMIT_BUG_ENTRY \ - ".section __bug_table,\"a\"\n" \ + ".section __bug_table,\"aw\"\n" \ "2:\t" PPC_LONG "1b\n" \ "\t.short %2\n" \ ".org 2b+%3\n" \
arch/s390/include/asm/bug.h +2 -2
@@ -14,7 +14,7 @@".section .rodata.str,\"aMS\",@progbits,1\n" \"2: .asciz \"" __FILE__"\"\n" \".previous\n" \ -".section __bug_table,\"a\"\n" \ +".section __bug_table,\"aw\"\n" \"3: .long 1b-3b,2b-3b\n" \" .short %0,%1\n" \" .org 3b+%2\n" \
@@ -30,7 +30,7 @@ asmvolatile ( \"0: j 0b+2\n" \"1:\n" \ -".section __bug_table,\"a\"\n" \ +".section __bug_table,\"aw\"\n" \"2: .long 1b-2b\n" \" .short %0\n" \ " .org 2b+%1\n" \
arch/sh/include/asm/bug.h +2 -2
@@ -24,14 +24,14 @@*/ #ifdef CONFIG_DEBUG_BUGVERBOSE #define _EMIT_BUG_ENTRY \ - "\t.pushsection __bug_table,\"a\"\n" \ + "\t.pushsection __bug_table,\"aw\"\n" \ "2:\t.long 1b, %O1\n" \ "\t.short %O2, %O3\n" \ "\t.org 2b+%O4\n" \ "\t.popsection\n"#else #define _EMIT_BUG_ENTRY \ - "\t.pushsection __bug_table,\"a\"\n" \ + "\t.pushsection __bug_table,\"aw\"\n" \ "2:\t.long 1b\n" \ "\t.short %O3\n" \ "\t.org 2b+%O4\n" \
arch/x86/include/asm/bug.h +2 -2
@@ -35,7 +35,7 @@#define _BUG_FLAGS (ins, flags) \ do { \ asm volatile("1:\t" ins "\n" \ - ".pushsection __bug_table,\"a\"\n" \ + ".pushsection __bug_table,\"aw\"\n" \ "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ "\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \ "\t.word %c1" "\t# bug_entry::line\n" \
@@ -52,7 +52,7 @@ do { \#define _BUG_FLAGS (ins, flags) \ do { \ asm volatile("1:\t" ins "\n" \ - ".pushsection __bug_table,\"a\"\n" \ + ".pushsection __bug_table,\"aw\"\n" \ "2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \ "\t.word %c0" "\t# bug_entry::flags\n" \ "\t.org 2b+%c1\n" \
Patches currently in stable-queue which might be from [email protected] are
queue-4.12/x86-asm-64-clear-ac-on-nmi-entries.patch queue-4.12/debug-fix-warn_on_once-for-modules.patch