Messages in this thread Patch in this message | | | Subject | [PATCH] X86: reboot-notify additions | From | Cliff Wickman <> | Date | Wed, 18 Jun 2008 17:03:35 -0500 |
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From: Cliff Wickman <cpw@sgi.com>
X86 reboot-notify additions.
This patch adds scans of the "reboot_notifier_list" callback chain in a three other places where the kernel is being stopped and/or restarted.
Adds calls to blocking_notifier_call_chain() in: crash_kexec(), emergency_restart(), sys_kexec_load()
In the crash_kexec() and emergency_restart() cases it is indicated to the called-back function that the system is not in a sane state, so that it can avoid taking a lock or some such potentially blocking action.
These callbacks are important to a partition system. The stopped kernel needs to inform other partitions of their need to disconnect (stop sharing memory).
Diffed against 2.6.26-rc6
Signed-off-by: Cliff Wickman <cpw@sgi.com> --- include/linux/notifier.h | 4 ++++ kernel/kexec.c | 5 +++++ kernel/sys.c | 1 + 3 files changed, 10 insertions(+)
Index: linux/include/linux/notifier.h =================================================================== --- linux.orig/include/linux/notifier.h +++ linux/include/linux/notifier.h @@ -202,6 +202,10 @@ static inline int notifier_to_errno(int #define SYS_RESTART SYS_DOWN #define SYS_HALT 0x0002 /* Notify of system halt */ #define SYS_POWER_OFF 0x0003 /* Notify of system power off */ +#define SYS_INSANE 0x0004 /* Notify of system error/panic/oops */ +/* For the SYS_INSANE case, no locks should be taken by the called-back + * function. The kernel is ready for an immediate reboot. + */ #define NETLINK_URELEASE 0x0001 /* Unicast netlink socket released */ Index: linux/kernel/kexec.c =================================================================== --- linux.orig/kernel/kexec.c +++ linux/kernel/kexec.c @@ -1001,6 +1001,9 @@ asmlinkage long sys_kexec_load(unsigned if (result) goto out; } + + blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); + /* Install the new kernel, and Uninstall the old */ image = xchg(dest_image, image); @@ -1068,6 +1071,8 @@ void crash_kexec(struct pt_regs *regs) if (!locked) { if (kexec_crash_image) { struct pt_regs fixed_regs; + blocking_notifier_call_chain(&reboot_notifier_list, + SYS_INSANE, NULL); crash_setup_regs(&fixed_regs, regs); crash_save_vmcoreinfo(); machine_crash_shutdown(&fixed_regs); Index: linux/kernel/sys.c =================================================================== --- linux.orig/kernel/sys.c +++ linux/kernel/sys.c @@ -270,6 +270,7 @@ out_unlock: */ void emergency_restart(void) { + blocking_notifier_call_chain(&reboot_notifier_list, SYS_INSANE, NULL); machine_emergency_restart(); } EXPORT_SYMBOL_GPL(emergency_restart);
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