This is a note to let you know that I've just added the patch titled crash: use macro to add crashk_res into iomem early for specific arch to the 6.8-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: crash-use-macro-to-add-crashk_res-into-iomem-early-for-specific-arch.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 32fbe5246582af4f611ccccee33fd6e559087252 Mon Sep 17 00:00:00 2001 From: Baoquan He <bhe@xxxxxxxxxx> Date: Mon, 25 Mar 2024 09:50:50 +0800 Subject: crash: use macro to add crashk_res into iomem early for specific arch From: Baoquan He <bhe@xxxxxxxxxx> commit 32fbe5246582af4f611ccccee33fd6e559087252 upstream. There are regression reports[1][2] that crashkernel region on x86_64 can't be added into iomem tree sometime. This causes the later failure of kdump loading. This happened after commit 4a693ce65b18 ("kdump: defer the insertion of crashkernel resources") was merged. Even though, these reported issues are proved to be related to other component, they are just exposed after above commmit applied, I still would like to keep crashk_res and crashk_low_res being added into iomem early as before because the early adding has been always there on x86_64 and working very well. For safety of kdump, Let's change it back. Here, add a macro HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY to limit that only ARCH defining the macro can have the early adding crashk_res/_low_res into iomem. Then define HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY on x86 to enable it. Note: In reserve_crashkernel_low(), there's a remnant of crashk_low_res handling which was mistakenly added back in commit 85fcde402db1 ("kexec: split crashkernel reservation code out from crash_core.c"). [1] [PATCH V2] x86/kexec: do not update E820 kexec table for setup_data https://lore.kernel.org/all/Zfv8iCL6CT2JqLIC@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx/T/#u [2] Question about Address Range Validation in Crash Kernel Allocation https://lore.kernel.org/all/4eeac1f733584855965a2ea62fa4da58@xxxxxxxxxx/T/#u Link: https://lkml.kernel.org/r/ZgDYemRQ2jxjLkq+@MiWiFi-R3L-srv Fixes: 4a693ce65b18 ("kdump: defer the insertion of crashkernel resources") Signed-off-by: Baoquan He <bhe@xxxxxxxxxx> Cc: Dave Young <dyoung@xxxxxxxxxx> Cc: Huacai Chen <chenhuacai@xxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jiri Bohac <jbohac@xxxxxxx> Cc: Li Huafei <lihuafei1@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Baoquan He <bhe@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/crash_core.h | 2 ++ kernel/crash_core.c | 8 ++++++++ 2 files changed, 10 insertions(+) --- a/arch/x86/include/asm/crash_core.h +++ b/arch/x86/include/asm/crash_core.h @@ -39,4 +39,6 @@ static inline unsigned long crash_low_si #endif } +#define HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY + #endif /* _X86_CRASH_CORE_H */ --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -376,6 +376,9 @@ static int __init reserve_crashkernel_lo crashk_low_res.start = low_base; crashk_low_res.end = low_base + low_size - 1; +#ifdef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY + insert_resource(&iomem_resource, &crashk_low_res); +#endif #endif return 0; } @@ -457,8 +460,12 @@ retry: crashk_res.start = crash_base; crashk_res.end = crash_base + crash_size - 1; +#ifdef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY + insert_resource(&iomem_resource, &crashk_res); +#endif } +#ifndef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY static __init int insert_crashkernel_resources(void) { if (crashk_res.start < crashk_res.end) @@ -471,6 +478,7 @@ static __init int insert_crashkernel_res } early_initcall(insert_crashkernel_resources); #endif +#endif int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map, void **addr, unsigned long *sz) Patches currently in stable-queue which might be from bhe@xxxxxxxxxx are queue-6.8/crash-use-macro-to-add-crashk_res-into-iomem-early-for-specific-arch.patch