From e545a6140b698b2494daf0b32107bdcc5e901390 Mon Sep 17 00:00:00 2001 From: Manfred Spraul Date: Sun, 7 Sep 2008 16:57:22 +0200 Subject: kernel/cpu.c: create a CPU_STARTING cpu_chain notifier Right now, there is no notifier that is called on a new cpu, before the new cpu begins processing interrupts/softirqs. Various kernel function would need that notification, e.g. kvm works around by calling smp_call_function_single(), rcu polls cpu_online_map. The patch adds a CPU_STARTING notification. It also adds a helper function that sends the message to all cpu_chain handlers. Tested on x86-64. All other archs are untested. Especially on sparc, I'm not sure if I got it right. Signed-off-by: Manfred Spraul Signed-off-by: Ingo Molnar --- arch/powerpc/kernel/smp.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 5337ca7bb64..c27b10a1bd7 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -453,6 +453,7 @@ int __devinit start_secondary(void *unused) secondary_cpu_time_init(); ipi_call_lock(); + notify_cpu_starting(cpu); cpu_set(cpu, cpu_online_map); /* Update sibling maps */ base = cpu_first_thread_in_core(cpu); -- cgit v1.2.3 From d7161a65341556bacb5e6654e133803f46f51063 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 26 Sep 2008 10:36:41 -0500 Subject: kgdb, x86, arm, mips, powerpc: ignore user space single stepping On the x86 arch, user space single step exceptions should be ignored if they occur in the kernel space, such as ptrace stepping through a system call. First check if it is kgdb that is executing a single step, then ensure it is not an accidental traversal into the user space, while in kgdb, any other time the TIF_SINGLESTEP is set, kgdb should ignore the exception. On x86, arm, mips and powerpc, the kgdb_contthread usage was inconsistent with the way single stepping is implemented in the kgdb core. The arch specific stub should always set the kgdb_cpu_doing_single_step correctly if it is single stepping. This allows kgdb to correctly process an instruction steps if ptrace happens to be requesting an instruction step over a system call. Signed-off-by: Jason Wessel --- arch/powerpc/kernel/kgdb.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index b4fdf2f2743..fe8f71dd0b3 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -347,9 +347,8 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code, linux_regs->msr |= MSR_SE; #endif kgdb_single_step = 1; - if (kgdb_contthread) - atomic_set(&kgdb_cpu_doing_single_step, - raw_smp_processor_id()); + atomic_set(&kgdb_cpu_doing_single_step, + raw_smp_processor_id()); } return 0; } -- cgit v1.2.3 From 61e9916eba35dfb76d38013a5aae9a59cc50877a Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 24 Sep 2008 22:56:25 +0000 Subject: powerpc: Fix failure to shutdown with CPU hotplug I tracked down the shutdown regression to CPUs not dying when being shut down during power-off. This turns out to be due to the system_state being SYSTEM_POWER_OFF, which this code doesn't take as a valid state for shutting off CPUs in. This has never made sense to me, but when I added hotplug code to implement hibernate I only "made it work" and did not question the need to check the system_state. Thomas Gleixner helped me dig, but the only thing we found is that it was added with the original commit that added CPU hotplug support. Signed-off-by: Johannes Berg Acked-by: Joel Schopp Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/idle.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c index d308a9f70f1..31982d05d81 100644 --- a/arch/powerpc/kernel/idle.c +++ b/arch/powerpc/kernel/idle.c @@ -34,11 +34,7 @@ #include #ifdef CONFIG_HOTPLUG_CPU -/* this is used for software suspend, and that shuts down - * CPUs even while the system is still booting... */ -#define cpu_should_die() (cpu_is_offline(smp_processor_id()) && \ - (system_state == SYSTEM_RUNNING \ - || system_state == SYSTEM_BOOTING)) +#define cpu_should_die() cpu_is_offline(smp_processor_id()) #else #define cpu_should_die() 0 #endif -- cgit v1.2.3