On 03/30/24 at 10:29am, gregkh@linuxfoundation.org wrote:

The patch below does not apply to the 6.8-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.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.8.y git checkout FETCH_HEAD git cherry-pick -x 32fbe5246582af4f611ccccee33fd6e559087252 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024033005-graded-dangle-3a21@gregkh' --subject-prefix 'PATCH 6.8.y' HEAD^..

Possible dependencies:

32fbe5246582 ("crash: use macro to add crashk_res into iomem early for specific arch") 85fcde402db1 ("kexec: split crashkernel reservation code out from crash_core.c")

I back ported it to 6.8 stable tree according to above steps of git operation as below. Please feel free to add it in.

From 04676ac2e7e5c45b54f6b9f78666005aa017fa61 Mon Sep 17 00:00:00 2001 From: Baoquan He bhe@redhat.com Date: Mon, 1 Apr 2024 16:35:31 +0800 Subject: [PATCH] crash: use macro to add crashk_res into iomem early for specific arch Content-type: text/plain

This is back ported to v6.8 stable tree.

commit 32fbe5246582af4f611ccccee33fd6e559087252 Author: Baoquan He bhe@redhat.com Date: Mon Mar 25 09:50:50 2024 +0800

crash: use macro to add crashk_res into iomem early for specific arch

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@darkstar.users.ipa.redhat.com/T...

[2] Question about Address Range Validation in Crash Kernel Allocation https://lore.kernel.org/all/4eeac1f733584855965a2ea62fa4da58@huawei.com/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@redhat.com Cc: Dave Young dyoung@redhat.com Cc: Huacai Chen chenhuacai@loongson.cn Cc: Ingo Molnar mingo@kernel.org Cc: Jiri Bohac jbohac@suse.cz Cc: Li Huafei lihuafei1@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org

Signed-off-by: Baoquan He bhe@redhat.com --- arch/x86/include/asm/crash_core.h | 2 ++ kernel/crash_core.c | 8 ++++++++ 2 files changed, 10 insertions(+)

diff --git a/arch/x86/include/asm/crash_core.h b/arch/x86/include/asm/crash_core.h index 76af98f4e801..041020da8d56 100644 --- 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_size_default(void) #endif }

+#define HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY + #endif /* _X86_CRASH_CORE_H */ diff --git a/kernel/crash_core.c b/kernel/crash_core.c index 75cd6a736d03..40bd908e0a81 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -376,6 +376,9 @@ static int __init reserve_crashkernel_low(unsigned long long low_size)

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 @@ void __init reserve_crashkernel_generic(char *cmdline,

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_resources(void) } 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)