diff options
Diffstat (limited to 'kernel/debug/debug_core.c')
| -rw-r--r-- | kernel/debug/debug_core.c | 122 |
1 files changed, 109 insertions, 13 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 7fda904fbac..1adf62b39b9 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -29,6 +29,7 @@ */ #include <linux/pid_namespace.h> #include <linux/clocksource.h> +#include <linux/serial_core.h> #include <linux/interrupt.h> #include <linux/spinlock.h> #include <linux/console.h> @@ -41,18 +42,19 @@ #include <linux/delay.h> #include <linux/sched.h> #include <linux/sysrq.h> +#include <linux/reboot.h> #include <linux/init.h> #include <linux/kgdb.h> #include <linux/kdb.h> #include <linux/pid.h> #include <linux/smp.h> #include <linux/mm.h> +#include <linux/vmacache.h> #include <linux/rcupdate.h> #include <asm/cacheflush.h> #include <asm/byteorder.h> #include <linux/atomic.h> -#include <asm/system.h> #include "debug_core.h" @@ -75,6 +77,8 @@ static int exception_level; struct kgdb_io *dbg_io_ops; static DEFINE_SPINLOCK(kgdb_registration_lock); +/* Action for the reboot notifiter, a global allow kdb to change it */ +static int kgdbreboot; /* kgdb console driver is loaded */ static int kgdb_con_registered; /* determine if kgdb console output should be used */ @@ -96,6 +100,7 @@ static int __init opt_kgdb_con(char *str) early_param("kgdbcon", opt_kgdb_con); module_param(kgdb_use_con, int, 0644); +module_param(kgdbreboot, int, 0644); /* * Holds information about breakpoints in a kernel. These breakpoints are @@ -220,10 +225,17 @@ static void kgdb_flush_swbreak_addr(unsigned long addr) if (!CACHE_FLUSH_IS_SAFE) return; - if (current->mm && current->mm->mmap_cache) { - flush_cache_range(current->mm->mmap_cache, - addr, addr + BREAK_INSTR_SIZE); + if (current->mm) { + int i; + + for (i = 0; i < VMACACHE_SIZE; i++) { + if (!current->vmacache[i]) + continue; + flush_cache_range(current->vmacache[i], + addr, addr + BREAK_INSTR_SIZE); + } } + /* Force flush instruction cache if it was outside the mm */ flush_icache_range(addr, addr + BREAK_INSTR_SIZE); } @@ -522,7 +534,7 @@ return_normal: kgdb_info[cpu].exception_state &= ~(DCPU_WANT_MASTER | DCPU_IS_SLAVE); kgdb_info[cpu].enter_kgdb--; - smp_mb__before_atomic_dec(); + smp_mb__before_atomic(); atomic_dec(&slaves_in_kgdb); dbg_touch_watchdogs(); local_irq_restore(flags); @@ -571,8 +583,12 @@ return_normal: raw_spin_lock(&dbg_slave_lock); #ifdef CONFIG_SMP + /* If send_ready set, slaves are already waiting */ + if (ks->send_ready) + atomic_set(ks->send_ready, 1); + /* Signal the other CPUs to enter kgdb_wait() */ - if ((!kgdb_single_step) && kgdb_do_roundup) + else if ((!kgdb_single_step) && kgdb_do_roundup) kgdb_roundup_cpus(flags); #endif @@ -646,7 +662,7 @@ kgdb_restore: kgdb_info[cpu].exception_state &= ~(DCPU_WANT_MASTER | DCPU_IS_SLAVE); kgdb_info[cpu].enter_kgdb--; - smp_mb__before_atomic_dec(); + smp_mb__before_atomic(); atomic_dec(&masters_in_kgdb); /* Free kgdb_active */ atomic_set(&kgdb_active, -1); @@ -669,22 +685,46 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) { struct kgdb_state kgdb_var; struct kgdb_state *ks = &kgdb_var; + int ret = 0; + + if (arch_kgdb_ops.enable_nmi) + arch_kgdb_ops.enable_nmi(0); + memset(ks, 0, sizeof(struct kgdb_state)); ks->cpu = raw_smp_processor_id(); ks->ex_vector = evector; ks->signo = signo; ks->err_code = ecode; - ks->kgdb_usethreadid = 0; ks->linux_regs = regs; if (kgdb_reenter_check(ks)) - return 0; /* Ouch, double exception ! */ + goto out; /* Ouch, double exception ! */ if (kgdb_info[ks->cpu].enter_kgdb != 0) - return 0; + goto out; + + ret = kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER); +out: + if (arch_kgdb_ops.enable_nmi) + arch_kgdb_ops.enable_nmi(1); + return ret; +} + +/* + * GDB places a breakpoint at this function to know dynamically + * loaded objects. It's not defined static so that only one instance with this + * name exists in the kernel. + */ - return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER); +static int module_event(struct notifier_block *self, unsigned long val, + void *data) +{ + return 0; } +static struct notifier_block dbg_module_load_nb = { + .notifier_call = module_event, +}; + int kgdb_nmicallback(int cpu, void *regs) { #ifdef CONFIG_SMP @@ -704,6 +744,31 @@ int kgdb_nmicallback(int cpu, void *regs) return 1; } +int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code, + atomic_t *send_ready) +{ +#ifdef CONFIG_SMP + if (!kgdb_io_ready(0) || !send_ready) + return 1; + + if (kgdb_info[cpu].enter_kgdb == 0) { + struct kgdb_state kgdb_var; + struct kgdb_state *ks = &kgdb_var; + + memset(ks, 0, sizeof(struct kgdb_state)); + ks->cpu = cpu; + ks->ex_vector = trapnr; + ks->signo = SIGTRAP; + ks->err_code = err_code; + ks->linux_regs = regs; + ks->send_ready = send_ready; + kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER); + return 0; + } +#endif + return 1; +} + static void kgdb_console_write(struct console *co, const char *s, unsigned count) { @@ -747,7 +812,7 @@ static void sysrq_handle_dbg(int key) static struct sysrq_key_op sysrq_dbg_op = { .handler = sysrq_handle_dbg, - .help_msg = "debug(G)", + .help_msg = "debug(g)", .action_msg = "DEBUG", }; #endif @@ -779,6 +844,33 @@ void __init dbg_late_init(void) kdb_init(KDB_INIT_FULL); } +static int +dbg_notify_reboot(struct notifier_block *this, unsigned long code, void *x) +{ + /* + * Take the following action on reboot notify depending on value: + * 1 == Enter debugger + * 0 == [the default] detatch debug client + * -1 == Do nothing... and use this until the board resets + */ + switch (kgdbreboot) { + case 1: + kgdb_breakpoint(); + case -1: + goto done; + } + if (!dbg_kdb_mode) + gdbstub_exit(code); +done: + return NOTIFY_DONE; +} + +static struct notifier_block dbg_reboot_notifier = { + .notifier_call = dbg_notify_reboot, + .next = NULL, + .priority = INT_MAX, +}; + static void kgdb_register_callbacks(void) { if (!kgdb_io_module_registered) { @@ -786,6 +878,8 @@ static void kgdb_register_callbacks(void) kgdb_arch_init(); if (!dbg_is_early) kgdb_arch_late(); + register_module_notifier(&dbg_module_load_nb); + register_reboot_notifier(&dbg_reboot_notifier); atomic_notifier_chain_register(&panic_notifier_list, &kgdb_panic_event_nb); #ifdef CONFIG_MAGIC_SYSRQ @@ -807,6 +901,8 @@ static void kgdb_unregister_callbacks(void) */ if (kgdb_io_module_registered) { kgdb_io_module_registered = 0; + unregister_reboot_notifier(&dbg_reboot_notifier); + unregister_module_notifier(&dbg_module_load_nb); atomic_notifier_chain_unregister(&panic_notifier_list, &kgdb_panic_event_nb); kgdb_arch_exit(); @@ -947,7 +1043,7 @@ int dbg_io_get_char(void) * otherwise as a quick means to stop program execution and "break" into * the debugger. */ -void kgdb_breakpoint(void) +noinline void kgdb_breakpoint(void) { atomic_inc(&kgdb_setting_breakpoint); wmb(); /* Sync point before breakpoint */ |