Subject: + kexec-migrate-to-reboot-cpu.patch added to -mm tree To: vgoyal@xxxxxxxxxx,bhe@xxxxxxxxxx,chaowang@xxxxxxxxxx,dyoung@xxxxxxxxxx,hpa@xxxxxxxxxxxxxxx,mwhitehe@xxxxxxxxxx,stable@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Mon, 11 Nov 2013 11:50:53 -0800 The patch titled Subject: kexec: migrate to reboot cpu has been added to the -mm tree. Its filename is kexec-migrate-to-reboot-cpu.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/kexec-migrate-to-reboot-cpu.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/kexec-migrate-to-reboot-cpu.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Vivek Goyal <vgoyal@xxxxxxxxxx> Subject: kexec: migrate to reboot cpu Commit 1b3a5d02ee0 ("reboot: move arch/x86 reboot= handling to generic kernel") moved reboot= handling to generic code. In the process it also removed the code in native_machine_shutdown() which are moving reboot process to reboot_cpu/cpu0. I guess that thought must have been that all reboot paths are calling migrate_to_reboot_cpu(), so we don't need this special handling. But kexec reboot path (kernel_kexec()) is not calling migrate_to_reboot_cpu() so above change broke kexec. Now reboot can happen on non-boot cpu and when INIT is sent in second kerneo to bring up BP, it brings down the machine. So start calling migrate_to_reboot_cpu() in kexec reboot path to avoid this problem. Reported-by: Matthew Whitehead <mwhitehe@xxxxxxxxxx> Reported-by: Dave Young <dyoung@xxxxxxxxxx> Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx> Tested-by: Baoquan He <bhe@xxxxxxxxxx> Bisected-by: WANG Chao <chaowang@xxxxxxxxxx> Tested-by: WANG Chao <chaowang@xxxxxxxxxx> Acked-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/reboot.h | 1 + kernel/kexec.c | 1 + kernel/reboot.c | 2 +- 3 files changed, 3 insertions(+), 1 deletion(-) diff -puN include/linux/reboot.h~kexec-migrate-to-reboot-cpu include/linux/reboot.h --- a/include/linux/reboot.h~kexec-migrate-to-reboot-cpu +++ a/include/linux/reboot.h @@ -43,6 +43,7 @@ extern int unregister_reboot_notifier(st * Architecture-specific implementations of sys_reboot commands. */ +extern void migrate_to_reboot_cpu(void); extern void machine_restart(char *cmd); extern void machine_halt(void); extern void machine_power_off(void); diff -puN kernel/kexec.c~kexec-migrate-to-reboot-cpu kernel/kexec.c --- a/kernel/kexec.c~kexec-migrate-to-reboot-cpu +++ a/kernel/kexec.c @@ -1676,6 +1676,7 @@ int kernel_kexec(void) #endif { kernel_restart_prepare(NULL); + migrate_to_reboot_cpu(); printk(KERN_EMERG "Starting new kernel\n"); machine_shutdown(); } diff -puN kernel/reboot.c~kexec-migrate-to-reboot-cpu kernel/reboot.c --- a/kernel/reboot.c~kexec-migrate-to-reboot-cpu +++ a/kernel/reboot.c @@ -104,7 +104,7 @@ int unregister_reboot_notifier(struct no } EXPORT_SYMBOL(unregister_reboot_notifier); -static void migrate_to_reboot_cpu(void) +void migrate_to_reboot_cpu(void) { /* The boot cpu is always logical cpu 0 */ int cpu = reboot_cpu; _ Patches currently in -mm which might be from vgoyal@xxxxxxxxxx are kexec-migrate-to-reboot-cpu.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html