diff options
Diffstat (limited to 'kernel/debug/debug_core.c')
| -rw-r--r-- | kernel/debug/debug_core.c | 87 |
1 files changed, 57 insertions, 30 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 0d7c08784efb..0557f24c6bca 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -41,6 +41,7 @@ #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> @@ -52,7 +53,6 @@ #include <asm/cacheflush.h> #include <asm/byteorder.h> #include <linux/atomic.h> -#include <asm/system.h> #include "debug_core.h" @@ -75,6 +75,8 @@ 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 +98,7 @@ 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 @@ -157,37 +160,39 @@ early_param("nokgdbroundup", opt_nokgdbroundup); * Weak aliases for breakpoint management, * can be overriden by architectures when needed: */ -int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) +int __weak kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) { int err; - err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); + err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr, + BREAK_INSTR_SIZE); if (err) return err; - - return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, - BREAK_INSTR_SIZE); + err = probe_kernel_write((char *)bpt->bpt_addr, + arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE); + return err; } -int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) +int __weak kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) { - return probe_kernel_write((char *)addr, - (char *)bundle, BREAK_INSTR_SIZE); + return probe_kernel_write((char *)bpt->bpt_addr, + (char *)bpt->saved_instr, BREAK_INSTR_SIZE); } int __weak kgdb_validate_break_address(unsigned long addr) { - char tmp_variable[BREAK_INSTR_SIZE]; + struct kgdb_bkpt tmp; int err; - /* Validate setting the breakpoint and then removing it. In the + /* Validate setting the breakpoint and then removing it. If the * remove fails, the kernel needs to emit a bad message because we * are deep trouble not being able to put things back the way we * found them. */ - err = kgdb_arch_set_breakpoint(addr, tmp_variable); + tmp.bpt_addr = addr; + err = kgdb_arch_set_breakpoint(&tmp); if (err) return err; - err = kgdb_arch_remove_breakpoint(addr, tmp_variable); + err = kgdb_arch_remove_breakpoint(&tmp); if (err) printk(KERN_ERR "KGDB: Critical breakpoint error, kernel " "memory destroyed at: %lx", addr); @@ -231,7 +236,6 @@ static void kgdb_flush_swbreak_addr(unsigned long addr) */ int dbg_activate_sw_breakpoints(void) { - unsigned long addr; int error; int ret = 0; int i; @@ -240,16 +244,15 @@ int dbg_activate_sw_breakpoints(void) if (kgdb_break[i].state != BP_SET) continue; - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_set_breakpoint(addr, - kgdb_break[i].saved_instr); + error = kgdb_arch_set_breakpoint(&kgdb_break[i]); if (error) { ret = error; - printk(KERN_INFO "KGDB: BP install failed: %lx", addr); + printk(KERN_INFO "KGDB: BP install failed: %lx", + kgdb_break[i].bpt_addr); continue; } - kgdb_flush_swbreak_addr(addr); + kgdb_flush_swbreak_addr(kgdb_break[i].bpt_addr); kgdb_break[i].state = BP_ACTIVE; } return ret; @@ -298,7 +301,6 @@ int dbg_set_sw_break(unsigned long addr) int dbg_deactivate_sw_breakpoints(void) { - unsigned long addr; int error; int ret = 0; int i; @@ -306,15 +308,14 @@ int dbg_deactivate_sw_breakpoints(void) for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if (kgdb_break[i].state != BP_ACTIVE) continue; - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_remove_breakpoint(addr, - kgdb_break[i].saved_instr); + error = kgdb_arch_remove_breakpoint(&kgdb_break[i]); if (error) { - printk(KERN_INFO "KGDB: BP remove failed: %lx\n", addr); + printk(KERN_INFO "KGDB: BP remove failed: %lx\n", + kgdb_break[i].bpt_addr); ret = error; } - kgdb_flush_swbreak_addr(addr); + kgdb_flush_swbreak_addr(kgdb_break[i].bpt_addr); kgdb_break[i].state = BP_SET; } return ret; @@ -348,7 +349,6 @@ int kgdb_isremovedbreak(unsigned long addr) int dbg_remove_all_break(void) { - unsigned long addr; int error; int i; @@ -356,12 +356,10 @@ int dbg_remove_all_break(void) for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if (kgdb_break[i].state != BP_ACTIVE) goto setundefined; - addr = kgdb_break[i].bpt_addr; - error = kgdb_arch_remove_breakpoint(addr, - kgdb_break[i].saved_instr); + error = kgdb_arch_remove_breakpoint(&kgdb_break[i]); if (error) printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", - addr); + kgdb_break[i].bpt_addr); setundefined: kgdb_break[i].state = BP_UNDEFINED; } @@ -784,6 +782,33 @@ 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) { @@ -791,6 +816,7 @@ static void kgdb_register_callbacks(void) kgdb_arch_init(); if (!dbg_is_early) kgdb_arch_late(); + register_reboot_notifier(&dbg_reboot_notifier); atomic_notifier_chain_register(&panic_notifier_list, &kgdb_panic_event_nb); #ifdef CONFIG_MAGIC_SYSRQ @@ -812,6 +838,7 @@ static void kgdb_unregister_callbacks(void) */ if (kgdb_io_module_registered) { kgdb_io_module_registered = 0; + unregister_reboot_notifier(&dbg_reboot_notifier); atomic_notifier_chain_unregister(&panic_notifier_list, &kgdb_panic_event_nb); kgdb_arch_exit(); |