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authorArd Biesheuvel <ardb@kernel.org>2022-01-18 19:32:17 +0100
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2022-01-19 12:10:54 +0100
commit9f80ccda53b9417236945bc7ece4b519037df74d (patch)
tree50c3e354b5f42fb421b6cda47225ac16fc271f4e /arch
parentARM: 9179/1: uaccess: avoid alignment faults in copy_[from|to]_kernel_nofault (diff)
downloadlinux-9f80ccda53b9417236945bc7ece4b519037df74d.tar.xz
linux-9f80ccda53b9417236945bc7ece4b519037df74d.zip
ARM: 9180/1: Thumb2: align ALT_UP() sections in modules sufficiently
When building for Thumb2, the .alt.smp.init sections that are emitted by the ALT_UP() patching code may not be 32-bit aligned, even though the fixup_smp_on_up() routine expects that. This results in alignment faults at module load time, which need to be fixed up by the fault handler. So let's align those sections explicitly, and prevent this from occurring. Cc: <stable@vger.kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/assembler.h2
-rw-r--r--arch/arm/include/asm/processor.h1
2 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 7d23d4bb2168..6fe67963ba5a 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -288,6 +288,7 @@
*/
#define ALT_UP(instr...) \
.pushsection ".alt.smp.init", "a" ;\
+ .align 2 ;\
.long 9998b - . ;\
9997: instr ;\
.if . - 9997b == 2 ;\
@@ -299,6 +300,7 @@
.popsection
#define ALT_UP_B(label) \
.pushsection ".alt.smp.init", "a" ;\
+ .align 2 ;\
.long 9998b - . ;\
W(b) . + (label - 9998b) ;\
.popsection
diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
index 6af68edfa53a..bdc35c0e8dfb 100644
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -96,6 +96,7 @@ unsigned long __get_wchan(struct task_struct *p);
#define __ALT_SMP_ASM(smp, up) \
"9998: " smp "\n" \
" .pushsection \".alt.smp.init\", \"a\"\n" \
+ " .align 2\n" \
" .long 9998b - .\n" \
" " up "\n" \
" .popsection\n"