kdump: make elfcorehdr_addr independent of CONFIG_PROC_VMCORE
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@redhat.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Simon Horman <horms@verge.net.au>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/ia64/kernel/crash_dump.c b/arch/ia64/kernel/crash_dump.c
index da60e90..23e9129 100644
--- a/arch/ia64/kernel/crash_dump.c
+++ b/arch/ia64/kernel/crash_dump.c
@@ -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 --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index de636b2..a0286be6 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -478,7 +478,12 @@
}
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 @@
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 --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index a323c9b..97e0563 100644
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -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 @@
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 @@
return 1;
}
__setup("elfcorehdr=", parse_elfcorehdr);
-#endif
static int __init parse_savemaxmem(char *p)
{
diff --git a/arch/sh/kernel/crash_dump.c b/arch/sh/kernel/crash_dump.c
index 4a2ecbe2..95d2162 100644
--- a/arch/sh/kernel/crash_dump.c
+++ b/arch/sh/kernel/crash_dump.c
@@ -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
diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c
index 72d0c56..f7cdb3b 100644
--- a/arch/x86/kernel/crash_dump_32.c
+++ b/arch/x86/kernel/crash_dump_32.c
@@ -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 --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index e90a60e..045b36c 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -10,6 +10,9 @@
#include <linux/uaccess.h>
#include <linux/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 --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 2255782..b2c9787 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -561,7 +561,13 @@
}
-#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 --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 841368b..4c65ca4 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -32,9 +32,6 @@
/* 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 --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index 025e4f5..de027d1 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -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 @@
#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;
