The patch titled
Subject: x86/purgatory: remove PGO flags
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
x86-purgatory-remove-pgo-flags.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/x86-purgatory-remove-pgo-flags.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Subject: x86/purgatory: remove PGO flags
Date: Fri, 19 May 2023 16:47:37 +0200
If profile-guided optimization is enabled, the purgatory ends up with
multiple .text sections. This is not supported by kexec and crashes the
system.
Link: https://lkml.kernel.org/r/20230321-kexec_clang16-v7-2-b05c520b7296@xxxxxxxxxxxx
Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Philipp Rudo <prudo@xxxxxxxxxx>
Cc: Ross Zwisler <zwisler@xxxxxxxxxx>
Cc: Simon Horman <horms@xxxxxxxxxx>
Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tom Rix <trix@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/purgatory/Makefile | 5 +++++
1 file changed, 5 insertions(+)
--- a/arch/x86/purgatory/Makefile~x86-purgatory-remove-pgo-flags
+++ a/arch/x86/purgatory/Makefile
@@ -14,6 +14,11 @@ $(obj)/sha256.o: $(srctree)/lib/crypto/s
CFLAGS_sha256.o := -D__DISABLE_EXPORTS
+# When profile-guided optimization is enabled, llvm emits two different
+# overlapping text sections, which is not supported by kexec. Remove profile
+# optimization flags.
+KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%,$(KBUILD_CFLAGS))
+
# When linking purgatory.ro with -r unresolved symbols are not checked,
# also link a purgatory.chk binary without -r to check for unresolved symbols.
PURGATORY_LDFLAGS := -e purgatory_start -z nodefaultlib
_
Patches currently in -mm which might be from ribalda@xxxxxxxxxxxx are
kexec-support-purgatories-with-texthot-sections.patch
x86-purgatory-remove-pgo-flags.patch
powerpc-purgatory-remove-pgo-flags.patch
riscv-purgatory-remove-pgo-flags.patch
