This is a note to let you know that I've just added the patch titled
ARM: 8971/1: replace the sole use of a symbol with its definition
to the 4.19-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:
arm-8971-1-replace-the-sole-use-of-a-symbol-with-its.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 12bea2007bfbdc1dd089dcd00694173bc9688b62
Author: Jian Cai <caij2003@xxxxxxxxx>
Date: Wed Apr 29 01:20:11 2020 +0100
ARM: 8971/1: replace the sole use of a symbol with its definition
commit a780e485b5768e78aef087502499714901b68cc4 upstream.
ALT_UP_B macro sets symbol up_b_offset via .equ to an expression
involving another symbol. The macro gets expanded twice when
arch/arm/kernel/sleep.S is assembled, creating a scenario where
up_b_offset is set to another expression involving symbols while its
current value is based on symbols. LLVM integrated assembler does not
allow such cases, and based on the documentation of binutils, "Values
that are based on expressions involving other symbols are allowed, but
some targets may restrict this to only being done once per assembly", so
it may be better to avoid such cases as it is not clearly stated which
targets should support or disallow them. The fix in this case is simple,
as up_b_offset has only one use, so we can replace the use with the
definition and get rid of up_b_offset.
Link:https://github.com/ClangBuiltLinux/linux/issues/920
Reviewed-by: Stefan Agner <stefan@xxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Jian Cai <caij2003@xxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 1935b580f0e8..3ab133dfb249 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -270,10 +270,9 @@
.endif ;\
.popsection
#define ALT_UP_B(label) \
- .equ up_b_offset, label - 9998b ;\
.pushsection ".alt.smp.init", "a" ;\
.long 9998b ;\
- W(b) . + up_b_offset ;\
+ W(b) . + (label - 9998b) ;\
.popsection
#else
#define ALT_SMP(instr...)
