From 2d16a9f778f7af55d8c488c7ad8e58c2577016fd Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Tue, 28 Nov 2023 13:44:57 +0800 Subject: [PATCH] kernel/Kconfig.kexec: drop select of KEXEC for CRASH_DUMP [ Upstream commit dccf78d39f1069a5ddf4328bf0c97aa5f2f4296e ] Ignat Korchagin complained that a potential config regression was introduced by commit 89cde455915f ("kexec: consolidate kexec and crash options into kernel/Kconfig.kexec"). Before the commit, CONFIG_CRASH_DUMP has no dependency on CONFIG_KEXEC. After the commit, CRASH_DUMP selects KEXEC. That enforces system to have CONFIG_KEXEC=y as long as CONFIG_CRASH_DUMP=Y which people may not want. In Ignat's case, he sets CONFIG_CRASH_DUMP=y, CONFIG_KEXEC_FILE=y and CONFIG_KEXEC=n because kexec_load interface could have security issue if kernel/initrd has no chance to be signed and verified. CRASH_DUMP has select of KEXEC because Eric, author of above commit, met a LKP report of build failure when posting patch of earlier version. Please see below link to get detail of the LKP report: https://lore.kernel.org/all/3e8eecd1-a277-2cfb-690e-5de2eb7b988e@oracle.com/T/#u In fact, that LKP report is triggered because arm's is wrapped in CONFIG_KEXEC ifdeffery scope. That is wrong. CONFIG_KEXEC controls the enabling/disabling of kexec_load interface, but not kexec feature. Removing the wrongly added CONFIG_KEXEC ifdeffery scope in of arm allows us to drop the select KEXEC for CRASH_DUMP. Meanwhile, change arch/arm/kernel/Makefile to let machine_kexec.o relocate_kernel.o depend on KEXEC_CORE. Link: https://lkml.kernel.org/r/20231128054457.659452-1-bhe@redhat.com Fixes: 89cde455915f ("kexec: consolidate kexec and crash options into kernel/Kconfig.kexec") Signed-off-by: Baoquan He Reported-by: Ignat Korchagin Tested-by: Ignat Korchagin [compile-time only] Tested-by: Alexander Gordeev Reviewed-by: Eric DeVolder Tested-by: Eric DeVolder Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- arch/arm/include/asm/kexec.h | 4 ---- arch/arm/kernel/Makefile | 2 +- kernel/Kconfig.kexec | 1 - 3 files changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/arm/include/asm/kexec.h b/arch/arm/include/asm/kexec.h index e62832d..a8287e7 100644 --- a/arch/arm/include/asm/kexec.h +++ b/arch/arm/include/asm/kexec.h @@ -2,8 +2,6 @@ #ifndef _ARM_KEXEC_H #define _ARM_KEXEC_H -#ifdef CONFIG_KEXEC - /* Maximum physical address we can use pages from */ #define KEXEC_SOURCE_MEMORY_LIMIT (-1UL) /* Maximum address we can reach in physical address mode */ @@ -82,6 +80,4 @@ static inline struct page *boot_pfn_to_page(unsigned long boot_pfn) #endif /* __ASSEMBLY__ */ -#endif /* CONFIG_KEXEC */ - #endif /* _ARM_KEXEC_H */ diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index d53f56d..771264d 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -59,7 +59,7 @@ obj-$(CONFIG_FUNCTION_TRACER) += entry-ftrace.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o patch.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o patch.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o -obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o +obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o # Main staffs in KPROBES are in arch/arm/probes/ . obj-$(CONFIG_KPROBES) += patch.o insn.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec index 9bfe68f..143f4d8 100644 --- a/kernel/Kconfig.kexec +++ b/kernel/Kconfig.kexec @@ -97,7 +97,6 @@ config CRASH_DUMP depends on ARCH_SUPPORTS_KEXEC select CRASH_CORE select KEXEC_CORE - select KEXEC help Generate crash dump after being started by kexec. This should be normally only set in special crash dump kernels -- 2.7.4