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

[<gregkh@linuxfoundation.org>]

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")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 32fbe5246582af4f611ccccee33fd6e559087252 Mon Sep 17 00:00:00 2001
From: Baoquan He <bhe@redhat.com>
Date: Mon, 25 Mar 2024 09:50:50 +0800
Subject: [PATCH] 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>

diff --git a/arch/x86/include/asm/crash_reserve.h b/arch/x86/include/asm/crash_reserve.h
index 152239f95541..7835b2cdff04 100644
--- a/arch/x86/include/asm/crash_reserve.h
+++ b/arch/x86/include/asm/crash_reserve.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_RESERVE_H */
diff --git a/kernel/crash_reserve.c b/kernel/crash_reserve.c
index bbb6c3cb00e4..066668799f75 100644
--- a/kernel/crash_reserve.c
+++ b/kernel/crash_reserve.c
@@ -366,7 +366,9 @@ 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;
 }
@@ -448,8 +450,12 @@ 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)
@@ -462,3 +468,4 @@ static __init int insert_crashkernel_resources(void)
 }
 early_initcall(insert_crashkernel_resources);
 #endif
+#endif