From: Hariprasad Nellitheertha <hari@in.ibm.com>
This patch fixes a problem where the kernel compilation was failing upon
disabling PROC_FS. It also ensures the reboot-on-panic kernel is pointed
to by a different variable , thereby separating the normal use of kexec
from the crashdump situation.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/Documentation/kdump.txt | 24 ++++++++----------------
25-akpm/include/linux/crash_dump.h | 11 ++++++++---
25-akpm/kernel/crash.c | 5 ++++-
3 files changed, 20 insertions(+), 20 deletions(-)
diff -puN Documentation/kdump.txt~crashdump-minor-bug-fixes-to-kexec-crashdump-code Documentation/kdump.txt
--- 25/Documentation/kdump.txt~crashdump-minor-bug-fixes-to-kexec-crashdump-code Wed Oct 20 16:22:21 2004
+++ 25-akpm/Documentation/kdump.txt Wed Oct 20 16:22:21 2004
@@ -27,19 +27,11 @@ SETUP
1) Obtain the appropriate -mm tree patch and apply it on to the vanilla
kernel tree.
-2) In order to enable the kernel to boot from a non-default location, the
- following patches (by Eric Biederman) needs to be applied.
-
- http://www.xmission.com/~ebiederm/files/kexec/2.6.8.1-kexec3/
- broken-out/highbzImage.i386.patch
- http://www.xmission.com/~ebiederm/files/kexec/2.6.8.1-kexec3/
- broken-out/vmlinux-lds.i386.patch
-
-3) Two kernels need to be built in order to get this feature working.
+2) Two kernels need to be built in order to get this feature working.
For the first kernel, choose the default values for the following options.
- a) Physical address where the kernel expects to be loaded
+ a) Physical address where the kernel is loaded
b) kexec system call
c) kernel crash dumps
@@ -51,28 +43,28 @@ SETUP
Also ensure you have CONFIG_HIGHMEM on.
-4) Boot into the first kernel. You are now ready to try out kexec based crash
+3) Boot into the first kernel. You are now ready to try out kexec based crash
dumps.
-5) Load the second kernel to be booted using
+4) Load the second kernel to be booted using
- kexec -l <second-kernel> --args-linux --append="root=<root-dev> dump
+ kexec -p <second-kernel> --args-linux --append="root=<root-dev> dump
init 1 memmap=exactmap memmap=640k@0 memmap=32M@16M"
Note that <second-kernel> has to be a vmlinux image. bzImage will not
work, as of now.
-6) Enable kexec based dumping by
+5) Enable kexec based dumping by
echo 1 > /proc/kexec-dump
If this is not set, the system will not do a kexec reboot in the event
of a panic.
-7) System reboots into the second kernel when a panic occurs.
+6) System reboots into the second kernel when a panic occurs.
You could write a module to call panic, for testing purposes.
-8) Write out the dump file using
+7) Write out the dump file using
cp /proc/vmcore <dump-file>
diff -puN include/linux/crash_dump.h~crashdump-minor-bug-fixes-to-kexec-crashdump-code include/linux/crash_dump.h
--- 25/include/linux/crash_dump.h~crashdump-minor-bug-fixes-to-kexec-crashdump-code Wed Oct 20 16:22:21 2004
+++ 25-akpm/include/linux/crash_dump.h Wed Oct 20 16:22:21 2004
@@ -15,15 +15,20 @@ extern void elf_kcore_store_hdr(char *,
#ifdef CONFIG_CRASH_DUMP
extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, int);
extern void __crash_machine_kexec(void);
-extern void crash_enable_by_proc(void);
-extern void crash_create_proc_entry(void);
extern int crash_dump_on;
static inline void crash_machine_kexec(void)
{
__crash_machine_kexec();
}
#else
+#define crash_machine_kexec() do { } while(0)
+#endif
+
+
+#if defined(CONFIG_CRASH_DUMP) && defined(CONFIG_PROC_FS)
+extern void crash_enable_by_proc(void);
+extern void crash_create_proc_entry(void);
+#else
#define crash_enable_by_proc() do { } while(0)
#define crash_create_proc_entry() do { } while(0)
-#define crash_machine_kexec() do { } while(0)
#endif
diff -puN kernel/crash.c~crashdump-minor-bug-fixes-to-kexec-crashdump-code kernel/crash.c
--- 25/kernel/crash.c~crashdump-minor-bug-fixes-to-kexec-crashdump-code Wed Oct 20 16:22:21 2004
+++ 25-akpm/kernel/crash.c Wed Oct 20 16:22:21 2004
@@ -16,6 +16,7 @@
#include <asm/io.h>
#include <asm/uaccess.h>
+#ifdef CONFIG_PROC_FS
/*
* Enable kexec reboot upon panic; for dumping
*/
@@ -57,6 +58,8 @@ void crash_create_proc_entry(void)
}
}
+#endif /* CONFIG_PROC_FS */
+
void __crash_machine_kexec(void)
{
struct kimage *image;
@@ -64,7 +67,7 @@ void __crash_machine_kexec(void)
if ((!crash_dump_on) || (crashed))
return;
- image = xchg(&kexec_image, 0);
+ image = xchg(&kexec_crash_image, 0);
if (image) {
crashed = 1;
printk(KERN_EMERG "kexec: opening parachute\n");
_