diff options
Diffstat (limited to 'kernel/debug/debug_core.c')
| -rw-r--r-- | kernel/debug/debug_core.c | 65 |
1 files changed, 64 insertions, 1 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 65c0f1363788..5cc608de6883 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -55,6 +55,7 @@ #include <linux/mm.h> #include <linux/vmacache.h> #include <linux/rcupdate.h> +#include <linux/irq.h> #include <asm/cacheflush.h> #include <asm/byteorder.h> @@ -220,6 +221,62 @@ 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; + int ret; + + for_each_online_cpu(cpu) { + /* No need to roundup ourselves */ + if (cpu == this_cpu) + continue; + + csd = &per_cpu(kgdb_roundup_csd, cpu); + + /* + * If it didn't round up last time, don't try again + * since smp_call_function_single_async() will block. + * + * If rounding_up is false then we know that the + * previous call must have at least started and that + * means smp_call_function_single_async() won't block. + */ + if (kgdb_info[cpu].rounding_up) + continue; + kgdb_info[cpu].rounding_up = true; + + csd->func = kgdb_call_nmi_hook; + ret = smp_call_function_single_async(cpu, csd); + if (ret) + kgdb_info[cpu].rounding_up = false; + } +} + +#endif + /* * Some architectures need cache flushes when we set/clear a * breakpoint: @@ -535,6 +592,8 @@ return_normal: arch_kgdb_ops.correct_hw_break(); if (trace_on) tracing_on(); + kgdb_info[cpu].debuggerinfo = NULL; + kgdb_info[cpu].task = NULL; kgdb_info[cpu].exception_state &= ~(DCPU_WANT_MASTER | DCPU_IS_SLAVE); kgdb_info[cpu].enter_kgdb--; @@ -593,7 +652,7 @@ return_normal: /* Signal the other CPUs to enter kgdb_wait() */ else if ((!kgdb_single_step) && kgdb_do_roundup) - kgdb_roundup_cpus(flags); + kgdb_roundup_cpus(); #endif /* @@ -667,6 +726,8 @@ kgdb_restore: if (trace_on) tracing_on(); + kgdb_info[cpu].debuggerinfo = NULL; + kgdb_info[cpu].task = NULL; kgdb_info[cpu].exception_state &= ~(DCPU_WANT_MASTER | DCPU_IS_SLAVE); kgdb_info[cpu].enter_kgdb--; @@ -747,6 +808,8 @@ int kgdb_nmicallback(int cpu, void *regs) struct kgdb_state kgdb_var; struct kgdb_state *ks = &kgdb_var; + kgdb_info[cpu].rounding_up = false; + memset(ks, 0, sizeof(struct kgdb_state)); ks->cpu = cpu; ks->linux_regs = regs; |