diff --git a/arch/arc/kernel/kgdb.c b/arch/arc/kernel/kgdb.c index 0932851028e0..68d9fe4b5aa7 100644 --- a/arch/arc/kernel/kgdb.c +++ b/arch/arc/kernel/kgdb.c @@ -192,18 +192,12 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) instruction_pointer(regs) = ip; } -static void kgdb_call_nmi_hook(void *ignored) +void kgdb_call_nmi_hook(void *ignored) { + /* Default implementation passes get_irq_regs() but we don't */ kgdb_nmicallback(raw_smp_processor_id(), NULL); } -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - struct kgdb_arch arch_kgdb_ops = { /* breakpoint instruction: TRAP_S 0x3 */ #ifdef CONFIG_CPU_BIG_ENDIAN diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c index f21077b077be..d9a69e941463 100644 --- a/arch/arm/kernel/kgdb.c +++ b/arch/arm/kernel/kgdb.c @@ -170,18 +170,6 @@ static struct undef_hook kgdb_compiled_brkpt_hook = { .fn = kgdb_compiled_brk_fn }; -static void kgdb_call_nmi_hook(void *ignored) -{ - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); -} - -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - static int __kgdb_notify(struct die_args *args, unsigned long cmd) { struct pt_regs *regs = args->regs; diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c index 12c339ff6e75..da880247c734 100644 --- a/arch/arm64/kernel/kgdb.c +++ b/arch/arm64/kernel/kgdb.c @@ -284,18 +284,6 @@ static struct step_hook kgdb_step_hook = { .fn = kgdb_step_brk_fn }; -static void kgdb_call_nmi_hook(void *ignored) -{ - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); -} - -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - static int __kgdb_notify(struct die_args *args, unsigned long cmd) { struct pt_regs *regs = args->regs; diff --git a/arch/hexagon/kernel/kgdb.c b/arch/hexagon/kernel/kgdb.c index 012e0e230ac2..b95d12038a4e 100644 --- a/arch/hexagon/kernel/kgdb.c +++ b/arch/hexagon/kernel/kgdb.c @@ -115,33 +115,6 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) instruction_pointer(regs) = pc; } -#ifdef CONFIG_SMP - -/** - * kgdb_roundup_cpus - Get other CPUs into a holding pattern - * - * On SMP systems, we need to get the attention of the other CPUs - * and get them be in a known state. This should do what is needed - * to get the other CPUs to call kgdb_wait(). Note that on some arches, - * the NMI approach is not used for rounding up all the CPUs. For example, - * in case of MIPS, smp_call_function() is used to roundup CPUs. - * - * On non-SMP systems, this is not called. - */ - -static void hexagon_kgdb_nmi_hook(void *ignored) -{ - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); -} - -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(hexagon_kgdb_nmi_hook, NULL, 0); - local_irq_disable(); -} -#endif - /* Not yet working */ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c index 2b05effc17b4..42f057a6c215 100644 --- a/arch/mips/kernel/kgdb.c +++ b/arch/mips/kernel/kgdb.c @@ -207,7 +207,7 @@ void arch_kgdb_breakpoint(void) ".set\treorder"); } -static void kgdb_call_nmi_hook(void *ignored) +void kgdb_call_nmi_hook(void *ignored) { mm_segment_t old_fs; @@ -219,13 +219,6 @@ static void kgdb_call_nmi_hook(void *ignored) set_fs(old_fs); } -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - static int compute_signal(int tt) { struct hard_trap_info *ht; diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index b0e804844be0..b4ce54d73337 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -117,7 +117,7 @@ int kgdb_skipexception(int exception, struct pt_regs *regs) return kgdb_isremovedbreak(regs->nip); } -static int kgdb_call_nmi_hook(struct pt_regs *regs) +static int kgdb_debugger_ipi(struct pt_regs *regs) { kgdb_nmicallback(raw_smp_processor_id(), regs); return 0; @@ -502,7 +502,7 @@ int kgdb_arch_init(void) old__debugger_break_match = __debugger_break_match; old__debugger_fault_handler = __debugger_fault_handler; - __debugger_ipi = kgdb_call_nmi_hook; + __debugger_ipi = kgdb_debugger_ipi; __debugger = kgdb_debugger; __debugger_bpt = kgdb_handle_breakpoint; __debugger_sstep = kgdb_singlestep; diff --git a/arch/sh/kernel/kgdb.c b/arch/sh/kernel/kgdb.c index cc57630f6bf2..14e012ad7c57 100644 --- a/arch/sh/kernel/kgdb.c +++ b/arch/sh/kernel/kgdb.c @@ -314,18 +314,6 @@ BUILD_TRAP_HANDLER(singlestep) local_irq_restore(flags); } -static void kgdb_call_nmi_hook(void *ignored) -{ - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); -} - -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - static int __kgdb_notify(struct die_args *args, unsigned long cmd) { int ret; diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 05e5b2eb0d32..24422865cd18 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -176,14 +176,25 @@ kgdb_arch_handle_exception(int vector, int signo, int err_code, char *remcom_out_buffer, struct pt_regs *regs); +/** + * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU + * @ignored: This parameter is only here to match the prototype. + * + * If you're using the default implementation of kgdb_roundup_cpus() + * this function will be called per CPU. If you don't implement + * kgdb_call_nmi_hook() a default will be used. + */ + +extern void kgdb_call_nmi_hook(void *ignored); + /** * kgdb_roundup_cpus - Get other CPUs into a holding pattern * * On SMP systems, we need to get the attention of the other CPUs * and get them into a known state. This should do what is needed * to get the other CPUs to call kgdb_wait(). Note that on some arches, - * the NMI approach is not used for rounding up all the CPUs. For example, - * in case of MIPS, smp_call_function() is used to roundup CPUs. + * the NMI approach is not used for rounding up all the CPUs. Normally + * those architectures can just not implement this and get the default. * * On non-SMP systems, this is not called. */ diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index f3cadda45f07..10db2833a423 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -55,6 +55,7 @@ #include #include #include +#include #include #include @@ -220,6 +221,46 @@ int __weak kgdb_skipexception(int exception, struct pt_regs *regs) return 0; } +#ifdef CONFIG_SMP + +/* + * Default (weak) implementation for kgdb_roundup_cpus + */ + +static DEFINE_PER_CPU(call_single_data_t, kgdb_roundup_csd); + +void __weak kgdb_call_nmi_hook(void *ignored) +{ + /* + * NOTE: get_irq_regs() is supposed to get the registers from + * before the IPI interrupt happened and so is supposed to + * show where the processor was. In some situations it's + * possible we might be called without an IPI, so it might be + * safer to figure out how to make kgdb_breakpoint() work + * properly here. + */ + kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); +} + +void __weak kgdb_roundup_cpus(void) +{ + call_single_data_t *csd; + int this_cpu = raw_smp_processor_id(); + int cpu; + + for_each_online_cpu(cpu) { + /* No need to roundup ourselves */ + if (cpu == this_cpu) + continue; + + csd = &per_cpu(kgdb_roundup_csd, cpu); + csd->func = kgdb_call_nmi_hook; + smp_call_function_single_async(cpu, csd); + } +} + +#endif + /* * Some architectures need cache flushes when we set/clear a * breakpoint: