[PATCH] kdump: Make elfcorehdr_addr independent ofCONFIG_PROC_VMCORE

From: Vivek Goyal
Date: Tue Jul 29 2008 - 10:44:24 EST

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o elfcorehdr_addr is used by not only the code under CONFIG_PROC_VMCORE but
also by the code which is not inside CONFIG_PROC_VMCORE. For example,
is_kdump_kernel() is used by powerpc code to determine if kernel is booting
after a panic then use previous kernel's TCE table. So even if
CONFIG_PROC_VMCORE is not set in second kernel, one should be able to
correctly determine that we are booting after a panic and setup calgary
iommu accordingly.

o So remove the assumption that elfcorehdr_addr is under CONFIG_PROC_VMCORE.

o Move definition of elfcorehdr_addr to arch dependent crash files.
(Unfortunately crash dump does not have an arch independent file otherwise
that would have been the best place).

o kexec.c is not the right place as one can Have CRASH_DUMP enabled in
second kernel without KEXEC being enabled.

o I don't see sh setup code parsing the command line for elfcorehdr_addr. I
am wondering how does vmcore interface work on sh. Anyway, I am atleast
defining elfcoredhr_addr so that compilation is not broken on sh.

Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
Acked-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Acked-by: Simon Horman <horms@xxxxxxxxxxxx>
Acked-by: Paul Mundt <lethal@xxxxxxxxxxxx>
---

arch/ia64/kernel/crash_dump.c | 4 ++++
arch/ia64/kernel/setup.c | 9 ++++++++-
arch/powerpc/kernel/crash_dump.c | 10 ++++++++--
arch/sh/kernel/crash_dump.c | 3 +++
arch/x86/kernel/crash_dump_32.c | 3 +++
arch/x86/kernel/crash_dump_64.c | 3 +++
arch/x86/kernel/setup.c | 8 +++++++-
fs/proc/vmcore.c | 3 ---
include/linux/crash_dump.h | 14 ++++++++++----
9 files changed, 46 insertions(+), 11 deletions(-)

diff -puN include/linux/crash_dump.h~remove-elfcore-hdr-addr-definition-vmcore include/linux/crash_dump.h
--- linux-2.6.27-pre-rc1/include/linux/crash_dump.h~remove-elfcore-hdr-addr-definition-vmcore 2008-07-28 12:00:44.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/include/linux/crash_dump.h 2008-07-28 12:00:56.000000000 -0400
@@ -9,11 +9,7 @@

#define ELFCORE_ADDR_MAX (-1ULL)

-#ifdef CONFIG_PROC_VMCORE
extern unsigned long long elfcorehdr_addr;
-#else
-static const unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
-#endif

extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
unsigned long, int);
@@ -28,6 +24,16 @@ extern struct proc_dir_entry *proc_vmcor

#define vmcore_elf_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))

+/*
+ * is_kdump_kernel() checks whether this kernel is booting after a panic of
+ * previous kernel or not. This is determined by checking if previous kernel
+ * has passed the elf core header address on command line.
+ *
+ * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
+ * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
+ * previous kernel.
+ */
+
static inline int is_kdump_kernel(void)
{
return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
diff -puN fs/proc/vmcore.c~remove-elfcore-hdr-addr-definition-vmcore fs/proc/vmcore.c
--- linux-2.6.27-pre-rc1/fs/proc/vmcore.c~remove-elfcore-hdr-addr-definition-vmcore 2008-07-28 09:19:50.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/fs/proc/vmcore.c 2008-07-28 09:20:10.000000000 -0400
@@ -32,9 +32,6 @@ static size_t elfcorebuf_sz;
/* Total size of vmcore file. */
static u64 vmcore_size;

-/* Stores the physical address of elf header of crash image. */
-unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
-
struct proc_dir_entry *proc_vmcore = NULL;

/* Reads a page from the oldmem device from given offset. */
diff -puN arch/x86/kernel/crash_dump_32.c~remove-elfcore-hdr-addr-definition-vmcore arch/x86/kernel/crash_dump_32.c
--- linux-2.6.27-pre-rc1/arch/x86/kernel/crash_dump_32.c~remove-elfcore-hdr-addr-definition-vmcore 2008-07-29 05:28:26.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/arch/x86/kernel/crash_dump_32.c 2008-07-29 05:28:26.000000000 -0400
@@ -13,6 +13,9 @@

static void *kdump_buf_page;

+/* Stores the physical address of elf header of crash image. */
+unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
diff -puN arch/x86/kernel/crash_dump_64.c~remove-elfcore-hdr-addr-definition-vmcore arch/x86/kernel/crash_dump_64.c
--- linux-2.6.27-pre-rc1/arch/x86/kernel/crash_dump_64.c~remove-elfcore-hdr-addr-definition-vmcore 2008-07-29 05:28:26.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/arch/x86/kernel/crash_dump_64.c 2008-07-29 05:28:26.000000000 -0400
@@ -11,6 +11,9 @@
#include <asm/uaccess.h>
#include <asm/io.h>

+/* Stores the physical address of elf header of crash image. */
+unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
diff -puN arch/x86/kernel/setup.c~remove-elfcore-hdr-addr-definition-vmcore arch/x86/kernel/setup.c
--- linux-2.6.27-pre-rc1/arch/x86/kernel/setup.c~remove-elfcore-hdr-addr-definition-vmcore 2008-07-29 05:28:26.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/arch/x86/kernel/setup.c 2008-07-29 05:28:26.000000000 -0400
@@ -558,7 +558,13 @@ static void __init reserve_standard_io_r

}

-#ifdef CONFIG_PROC_VMCORE
+/*
+ * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
+ * is_kdump_kernel() to determine if we are booting after a panic. Hence
+ * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
+ */
+
+#ifdef CONFIG_CRASH_DUMP
/* elfcorehdr= specifies the location of elf core header
* stored by the crashed kernel. This option will be passed
* by kexec loader to the capture kernel.
diff -puN arch/powerpc/kernel/crash_dump.c~remove-elfcore-hdr-addr-definition-vmcore arch/powerpc/kernel/crash_dump.c
--- linux-2.6.27-pre-rc1/arch/powerpc/kernel/crash_dump.c~remove-elfcore-hdr-addr-definition-vmcore 2008-07-29 05:30:33.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/arch/powerpc/kernel/crash_dump.c 2008-07-29 05:30:33.000000000 -0400
@@ -27,6 +27,9 @@
#define DBG(fmt...)
#endif

+/* Stores the physical address of elf header of crash image. */
+unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+
void __init reserve_kdump_trampoline(void)
{
lmb_reserve(0, KDUMP_RESERVE_LIMIT);
@@ -66,7 +69,11 @@ void __init setup_kdump_trampoline(void)
DBG(" <- setup_kdump_trampoline()\n");
}

-#ifdef CONFIG_PROC_VMCORE
+/*
+ * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
+ * is_kdump_kernel() to determine if we are booting after a panic. Hence
+ * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
+ */
static int __init parse_elfcorehdr(char *p)
{
if (p)
@@ -75,7 +82,6 @@ static int __init parse_elfcorehdr(char
return 1;
}
__setup("elfcorehdr=", parse_elfcorehdr);
-#endif

static int __init parse_savemaxmem(char *p)
{
diff -puN arch/ia64/kernel/setup.c~remove-elfcore-hdr-addr-definition-vmcore arch/ia64/kernel/setup.c
--- linux-2.6.27-pre-rc1/arch/ia64/kernel/setup.c~remove-elfcore-hdr-addr-definition-vmcore 2008-07-29 05:30:54.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/arch/ia64/kernel/setup.c 2008-07-29 05:30:54.000000000 -0400
@@ -478,7 +478,12 @@ static __init int setup_nomca(char *s)
}
early_param("nomca", setup_nomca);

-#ifdef CONFIG_PROC_VMCORE
+/*
+ * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
+ * is_kdump_kernel() to determine if we are booting after a panic. Hence
+ * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
+ */
+#ifdef CONFIG_CRASH_DUMP
/* elfcorehdr= specifies the location of elf core header
* stored by the crashed kernel.
*/
@@ -491,7 +496,9 @@ static int __init parse_elfcorehdr(char
return 0;
}
early_param("elfcorehdr", parse_elfcorehdr);
+#endif

+#ifdef CONFIG_PROC_VMCORE
int __init reserve_elfcorehdr(unsigned long *start, unsigned long *end)
{
unsigned long length;
diff -puN arch/ia64/kernel/crash_dump.c~remove-elfcore-hdr-addr-definition-vmcore arch/ia64/kernel/crash_dump.c
--- linux-2.6.27-pre-rc1/arch/ia64/kernel/crash_dump.c~remove-elfcore-hdr-addr-definition-vmcore 2008-07-29 05:37:10.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/arch/ia64/kernel/crash_dump.c 2008-07-29 05:37:58.000000000 -0400
@@ -8,10 +8,14 @@

#include <linux/errno.h>
#include <linux/types.h>
+#include <linux/crash_dump.h>

#include <asm/page.h>
#include <asm/uaccess.h>

+/* Stores the physical address of elf header of crash image. */
+unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
diff -puN arch/sh/kernel/crash_dump.c~remove-elfcore-hdr-addr-definition-vmcore arch/sh/kernel/crash_dump.c
--- linux-2.6.27-pre-rc1/arch/sh/kernel/crash_dump.c~remove-elfcore-hdr-addr-definition-vmcore 2008-07-29 05:31:04.000000000 -0400
+++ linux-2.6.27-pre-rc1-root/arch/sh/kernel/crash_dump.c 2008-07-29 05:31:04.000000000 -0400
@@ -10,6 +10,9 @@
#include <linux/io.h>
#include <asm/uaccess.h>

+/* Stores the physical address of elf header of crash image. */
+unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
_
--
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Next message: Dominik Brodowski: "Re: linux-next: Tree for July 29"
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