This is a note to let you know that I've just added the patch titled
x86/boot: Avoid using Intel mnemonics in AT&T syntax asm
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:
x86-boot-avoid-using-intel-mnemonics-in-at-t-syntax-asm.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.
>From 7c6dd961d0c8e7e8f9fdc65071fb09ece702e18d Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Tue, 10 Jan 2023 12:15:40 +0100
Subject: x86/boot: Avoid using Intel mnemonics in AT&T syntax asm
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
commit 7c6dd961d0c8e7e8f9fdc65071fb09ece702e18d upstream.
With 'GNU assembler (GNU Binutils for Debian) 2.39.90.20221231' the
build now reports:
arch/x86/realmode/rm/../../boot/bioscall.S: Assembler messages:
arch/x86/realmode/rm/../../boot/bioscall.S:35: Warning: found `movsd'; assuming `movsl' was meant
arch/x86/realmode/rm/../../boot/bioscall.S:70: Warning: found `movsd'; assuming `movsl' was meant
arch/x86/boot/bioscall.S: Assembler messages:
arch/x86/boot/bioscall.S:35: Warning: found `movsd'; assuming `movsl' was meant
arch/x86/boot/bioscall.S:70: Warning: found `movsd'; assuming `movsl' was meant
Which is due to:
PR gas/29525
Note that with the dropped CMPSD and MOVSD Intel Syntax string insn
templates taking operands, mixed IsString/non-IsString template groups
(with memory operands) cannot occur anymore. With that
maybe_adjust_templates() becomes unnecessary (and is hence being
removed).
More details: https://sourceware.org/bugzilla/show_bug.cgi?id=29525
Borislav Petkov further explains:
" the particular problem here is is that the 'd' suffix is
"conflicting" in the sense that you can have SSE mnemonics like movsD %xmm...
and the same thing also for string ops (which is the case here) so apparently
the agreement in binutils land is to use the always accepted suffixes 'l' or 'q'
and phase out 'd' slowly... "
Fixes: 7a734e7dd93b ("x86, setup: "glove box" BIOS calls -- infrastructure")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/Y71I3Ex2pvIxMpsP@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/boot/bioscall.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/boot/bioscall.S
+++ b/arch/x86/boot/bioscall.S
@@ -35,7 +35,7 @@ intcall:
movw %dx, %si
movw %sp, %di
movw $11, %cx
- rep; movsd
+ rep; movsl
/* Pop full state from the stack */
popal
@@ -70,7 +70,7 @@ intcall:
jz 4f
movw %sp, %si
movw $11, %cx
- rep; movsd
+ rep; movsl
4: addw $44, %sp
/* Restore state and return */
Patches currently in stable-queue which might be from peterz@xxxxxxxxxxxxx are
queue-4.19/perf-x86-intel-uncore-fix-reference-count-leak-in-hs.patch
queue-4.19/perf-debug-set-debug_peo_args-and-redirect_to_stderr.patch
queue-4.19/perf-probe-fix-to-get-the-dw_at_decl_file-and-dw_at_.patch
queue-4.19/perf-fix-possible-memleak-in-pmu_dev_alloc.patch
queue-4.19/perf-probe-use-dwarf_attr_integrate-as-generic-dwarf.patch
queue-4.19/x86-boot-avoid-using-intel-mnemonics-in-at-t-syntax-asm.patch
queue-4.19/perf-symbol-correction-while-adjusting-symbol.patch
