Re: FAILED: patch "[PATCH] crash: use macro to add crashk_res into iomem early for" failed to apply to 6.8-stable tree

[Baoquan He <bhe@redhat.com>]

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/#u

    [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)
-- 
2.41.0