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authorIan Campbell <ian.campbell@xensource.com>2007-05-02 19:27:09 +0200
committerAndi Kleen <andi@basil.nowhere.org>2007-05-02 19:27:09 +0200
commit79e030114a8d97a1dcd593ab84fb986f8c91c536 (patch)
treeae96f84611dd963c11ce2962a67197030ddd0f3e
parenteab0c72aecd7982b2c848f7d493ba379efcef15e (diff)
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[PATCH] i386: Allow i386 crash kernels to handle x86_64 dumps
The specific case I am encountering is kdump under Xen with a 64 bit hypervisor and 32 bit kernel/userspace. The dump created is 64 bit due to the hypervisor but the dump kernel is 32 bit for maximum compatibility. It's possibly less likely to be useful in a purely native scenario but I see no reason to disallow it. [akpm@linux-foundation.org: build fix] Signed-off-by: Ian Campbell <ian.campbell@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Vivek Goyal <vgoyal@in.ibm.com> Cc: Horms <horms@verge.net.au> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--fs/proc/vmcore.c2
-rw-r--r--include/asm-i386/kexec.h3
-rw-r--r--include/linux/crash_dump.h8
3 files changed, 12 insertions, 1 deletions
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index d96050728c43..523e1098ae88 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -514,7 +514,7 @@ static int __init parse_crash_elf64_headers(void)
/* Do some basic Verification. */
if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
(ehdr.e_type != ET_CORE) ||
- !elf_check_arch(&ehdr) ||
+ !vmcore_elf_check_arch(&ehdr) ||
ehdr.e_ident[EI_CLASS] != ELFCLASS64 ||
ehdr.e_ident[EI_VERSION] != EV_CURRENT ||
ehdr.e_version != EV_CURRENT ||
diff --git a/include/asm-i386/kexec.h b/include/asm-i386/kexec.h
index c5b4ab95bdc2..bcb5b21de2d2 100644
--- a/include/asm-i386/kexec.h
+++ b/include/asm-i386/kexec.h
@@ -42,6 +42,9 @@
/* The native architecture */
#define KEXEC_ARCH KEXEC_ARCH_386
+/* We can also handle crash dumps from 64 bit kernel. */
+#define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64)
+
#define MAX_NOTE_BYTES 1024
/* CPU does not save ss and esp on stack if execution is already
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index 32503657f14f..22c7ac5cd80c 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -14,5 +14,13 @@ extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
extern const struct file_operations proc_vmcore_operations;
extern struct proc_dir_entry *proc_vmcore;
+/* Architecture code defines this if there are other possible ELF
+ * machine types, e.g. on bi-arch capable hardware. */
+#ifndef vmcore_elf_check_arch_cross
+#define vmcore_elf_check_arch_cross(x) 0
+#endif
+
+#define vmcore_elf_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
+
#endif /* CONFIG_CRASH_DUMP */
#endif /* LINUX_CRASHDUMP_H */