* FAILED: patch "[PATCH] MIPS: Support binutils configured with" failed to apply to 5.4-stable tree
@ 2021-03-01 9:57 gregkh
0 siblings, 0 replies; only message in thread
From: gregkh @ 2021-03-01 9:57 UTC (permalink / raw)
To: aurelien, syq, tsbogend; +Cc: stable
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 5373ae67c3aad1ab306cc722b5a80b831eb4d4d1 Mon Sep 17 00:00:00 2001
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Sat, 9 Jan 2021 20:30:47 +0100
Subject: [PATCH] MIPS: Support binutils configured with
--enable-mips-fix-loongson3-llsc=yes
From version 2.35, binutils can be configured with
--enable-mips-fix-loongson3-llsc=yes, which means it defaults to
-mfix-loongson3-llsc. This breaks labels which might then point at the
wrong instruction.
The workaround to explicitly pass -mno-fix-loongson3-llsc has been
added in Linux version 5.1, but is only enabled when building a Loongson
64 kernel. As vendors might use a common toolchain for building Loongson
and non-Loongson kernels, just move that workaround to
arch/mips/Makefile. At the same time update the comments to reflect the
current status.
Cc: stable@vger.kernel.org # 5.1+
Cc: YunQiang Su <syq@debian.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index cd4343edeb11..5ffdd67093bc 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -136,6 +136,25 @@ cflags-$(CONFIG_SB1XXX_CORELIS) += $(call cc-option,-mno-sched-prolog) \
#
cflags-y += -fno-stack-check
+# binutils from v2.35 when built with --enable-mips-fix-loongson3-llsc=yes,
+# supports an -mfix-loongson3-llsc flag which emits a sync prior to each ll
+# instruction to work around a CPU bug (see __SYNC_loongson3_war in asm/sync.h
+# for a description).
+#
+# We disable this in order to prevent the assembler meddling with the
+# instruction that labels refer to, ie. if we label an ll instruction:
+#
+# 1: ll v0, 0(a0)
+#
+# ...then with the assembler fix applied the label may actually point at a sync
+# instruction inserted by the assembler, and if we were using the label in an
+# exception table the table would no longer contain the address of the ll
+# instruction.
+#
+# Avoid this by explicitly disabling that assembler behaviour.
+#
+cflags-y += $(call as-option,-Wa$(comma)-mno-fix-loongson3-llsc,)
+
#
# CPU-dependent compiler/assembler options for optimization.
#
diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform
index ec42c5085905..e2354e128d9a 100644
--- a/arch/mips/loongson64/Platform
+++ b/arch/mips/loongson64/Platform
@@ -5,28 +5,6 @@
cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap
-#
-# Some versions of binutils, not currently mainline as of 2019/02/04, support
-# an -mfix-loongson3-llsc flag which emits a sync prior to each ll instruction
-# to work around a CPU bug (see __SYNC_loongson3_war in asm/sync.h for a
-# description).
-#
-# We disable this in order to prevent the assembler meddling with the
-# instruction that labels refer to, ie. if we label an ll instruction:
-#
-# 1: ll v0, 0(a0)
-#
-# ...then with the assembler fix applied the label may actually point at a sync
-# instruction inserted by the assembler, and if we were using the label in an
-# exception table the table would no longer contain the address of the ll
-# instruction.
-#
-# Avoid this by explicitly disabling that assembler behaviour. If upstream
-# binutils does not merge support for the flag then we can revisit & remove
-# this later - for now it ensures vendor toolchains don't cause problems.
-#
-cflags-$(CONFIG_CPU_LOONGSON64) += $(call as-option,-Wa$(comma)-mno-fix-loongson3-llsc,)
-
#
# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a
# as MIPS64 R2; older versions as just R1. This leaves the possibility open
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2021-03-01 9:57 FAILED: patch "[PATCH] MIPS: Support binutils configured with" failed to apply to 5.4-stable tree gregkh
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