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kernel/debug/debug_core.c
22.7 KB
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/* |
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* Kernel Debug Core |
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* * Maintainer: Jason Wessel <jason.wessel@windriver.com> * * Copyright (C) 2000-2001 VERITAS Software Corporation. * Copyright (C) 2002-2004 Timesys Corporation * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com> |
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* Copyright (C) 2004 Pavel Machek <pavel@ucw.cz> |
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* Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org> * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. |
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* Copyright (C) 2005-2009 Wind River Systems, Inc. |
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* Copyright (C) 2007 MontaVista Software, Inc. * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> * * Contributors at various stages not listed above: * Jason Wessel ( jason.wessel@windriver.com ) * George Anzinger <george@mvista.com> * Anurekh Saxena (anurekh.saxena@timesys.com) * Lake Stevens Instrument Division (Glenn Engel) * Jim Kingdon, Cygnus Support. * * Original KGDB stub: David Grothe <dave@gcom.com>, * Tigran Aivazian <tigran@sco.com> * * This file is licensed under the terms of the GNU General Public License * version 2. This program is licensed "as is" without any warranty of any * kind, whether express or implied. */ #include <linux/pid_namespace.h> |
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#include <linux/clocksource.h> |
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#include <linux/interrupt.h> #include <linux/spinlock.h> #include <linux/console.h> #include <linux/threads.h> #include <linux/uaccess.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/ptrace.h> |
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#include <linux/string.h> #include <linux/delay.h> #include <linux/sched.h> #include <linux/sysrq.h> #include <linux/init.h> #include <linux/kgdb.h> |
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#include <linux/kdb.h> |
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#include <linux/pid.h> #include <linux/smp.h> #include <linux/mm.h> |
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#include <linux/rcupdate.h> |
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#include <asm/cacheflush.h> #include <asm/byteorder.h> |
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#include <linux/atomic.h> |
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#include <asm/system.h> |
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#include "debug_core.h" |
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|
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static int kgdb_break_asap; |
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|
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struct debuggerinfo_struct kgdb_info[NR_CPUS]; |
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/** * kgdb_connected - Is a host GDB connected to us? */ int kgdb_connected; EXPORT_SYMBOL_GPL(kgdb_connected); /* All the KGDB handlers are installed */ |
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int kgdb_io_module_registered; |
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/* Guard for recursive entry */ static int exception_level; |
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struct kgdb_io *dbg_io_ops; |
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static DEFINE_SPINLOCK(kgdb_registration_lock); /* kgdb console driver is loaded */ static int kgdb_con_registered; /* determine if kgdb console output should be used */ static int kgdb_use_con; |
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/* Flag for alternate operations for early debugging */ bool dbg_is_early = true; |
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/* Next cpu to become the master debug core */ int dbg_switch_cpu; /* Use kdb or gdbserver mode */ |
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int dbg_kdb_mode = 1; |
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static int __init opt_kgdb_con(char *str) { kgdb_use_con = 1; return 0; } early_param("kgdbcon", opt_kgdb_con); module_param(kgdb_use_con, int, 0644); /* * Holds information about breakpoints in a kernel. These breakpoints are * added and removed by gdb. */ static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } }; /* * The CPU# of the active CPU, or -1 if none: */ atomic_t kgdb_active = ATOMIC_INIT(-1); |
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EXPORT_SYMBOL_GPL(kgdb_active); |
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static DEFINE_RAW_SPINLOCK(dbg_master_lock); static DEFINE_RAW_SPINLOCK(dbg_slave_lock); |
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/* * We use NR_CPUs not PERCPU, in case kgdb is used to debug early * bootup code (which might not have percpu set up yet): */ |
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static atomic_t masters_in_kgdb; static atomic_t slaves_in_kgdb; |
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static atomic_t kgdb_break_tasklet_var; |
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atomic_t kgdb_setting_breakpoint; struct task_struct *kgdb_usethread; struct task_struct *kgdb_contthread; int kgdb_single_step; |
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static pid_t kgdb_sstep_pid; |
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/* to keep track of the CPU which is doing the single stepping*/ atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1); /* * If you are debugging a problem where roundup (the collection of * all other CPUs) is a problem [this should be extremely rare], * then use the nokgdbroundup option to avoid roundup. In that case * the other CPUs might interfere with your debugging context, so * use this with care: */ |
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static int kgdb_do_roundup = 1; |
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static int __init opt_nokgdbroundup(char *str) { kgdb_do_roundup = 0; return 0; } early_param("nokgdbroundup", opt_nokgdbroundup); /* * Finally, some KGDB code :-) */ /* * Weak aliases for breakpoint management, * can be overriden by architectures when needed: */ |
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int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) { int err; err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); if (err) return err; return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE); } int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) { return probe_kernel_write((char *)addr, (char *)bundle, BREAK_INSTR_SIZE); } |
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int __weak kgdb_validate_break_address(unsigned long addr) { char tmp_variable[BREAK_INSTR_SIZE]; int err; /* Validate setting the breakpoint and then removing it. In 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); if (err) return err; err = kgdb_arch_remove_breakpoint(addr, tmp_variable); if (err) printk(KERN_ERR "KGDB: Critical breakpoint error, kernel " "memory destroyed at: %lx", addr); return err; } |
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unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs) { return instruction_pointer(regs); } int __weak kgdb_arch_init(void) { return 0; } |
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int __weak kgdb_skipexception(int exception, struct pt_regs *regs) { return 0; } |
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/* |
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* Some architectures need cache flushes when we set/clear a * breakpoint: */ static void kgdb_flush_swbreak_addr(unsigned long addr) { if (!CACHE_FLUSH_IS_SAFE) return; |
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if (current->mm && current->mm->mmap_cache) { |
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flush_cache_range(current->mm->mmap_cache, addr, addr + BREAK_INSTR_SIZE); |
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} |
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/* Force flush instruction cache if it was outside the mm */ flush_icache_range(addr, addr + BREAK_INSTR_SIZE); |
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} /* * SW breakpoint management: */ |
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int dbg_activate_sw_breakpoints(void) |
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{ unsigned long addr; |
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int error; int ret = 0; |
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int i; for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { 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); |
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if (error) { ret = error; printk(KERN_INFO "KGDB: BP install failed: %lx", addr); continue; } |
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kgdb_flush_swbreak_addr(addr); kgdb_break[i].state = BP_ACTIVE; } |
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return ret; |
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} |
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int dbg_set_sw_break(unsigned long addr) |
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{ int err = kgdb_validate_break_address(addr); int breakno = -1; int i; if (err) return err; for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if ((kgdb_break[i].state == BP_SET) && (kgdb_break[i].bpt_addr == addr)) return -EEXIST; } for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if (kgdb_break[i].state == BP_REMOVED && kgdb_break[i].bpt_addr == addr) { breakno = i; break; } } if (breakno == -1) { for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if (kgdb_break[i].state == BP_UNDEFINED) { breakno = i; break; } } } if (breakno == -1) return -E2BIG; kgdb_break[breakno].state = BP_SET; kgdb_break[breakno].type = BP_BREAKPOINT; kgdb_break[breakno].bpt_addr = addr; return 0; } |
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int dbg_deactivate_sw_breakpoints(void) |
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{ unsigned long addr; |
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int error; int ret = 0; |
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int i; 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); |
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if (error) { printk(KERN_INFO "KGDB: BP remove failed: %lx ", addr); ret = error; } |
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kgdb_flush_swbreak_addr(addr); kgdb_break[i].state = BP_SET; } |
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return ret; |
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} |
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int dbg_remove_sw_break(unsigned long addr) |
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{ int i; for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if ((kgdb_break[i].state == BP_SET) && (kgdb_break[i].bpt_addr == addr)) { kgdb_break[i].state = BP_REMOVED; return 0; } } return -ENOENT; } int kgdb_isremovedbreak(unsigned long addr) { int i; for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { if ((kgdb_break[i].state == BP_REMOVED) && (kgdb_break[i].bpt_addr == addr)) return 1; } return 0; } |
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int dbg_remove_all_break(void) |
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{ unsigned long addr; int error; int i; /* Clear memory breakpoints. */ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
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if (kgdb_break[i].state != BP_ACTIVE) goto setundefined; |
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addr = kgdb_break[i].bpt_addr; error = kgdb_arch_remove_breakpoint(addr, kgdb_break[i].saved_instr); if (error) |
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printk(KERN_ERR "KGDB: breakpoint remove failed: %lx ", addr); setundefined: kgdb_break[i].state = BP_UNDEFINED; |
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} /* Clear hardware breakpoints. */ if (arch_kgdb_ops.remove_all_hw_break) arch_kgdb_ops.remove_all_hw_break(); return 0; } /* |
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* Return true if there is a valid kgdb I/O module. Also if no * debugger is attached a message can be printed to the console about * waiting for the debugger to attach. * * The print_wait argument is only to be true when called from inside * the core kgdb_handle_exception, because it will wait for the * debugger to attach. */ static int kgdb_io_ready(int print_wait) { |
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if (!dbg_io_ops) |
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return 0; if (kgdb_connected) return 1; if (atomic_read(&kgdb_setting_breakpoint)) return 1; |
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if (print_wait) { #ifdef CONFIG_KGDB_KDB if (!dbg_kdb_mode) printk(KERN_CRIT "KGDB: waiting... or $3#33 for KDB "); #else |
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printk(KERN_CRIT "KGDB: Waiting for remote debugger "); |
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#endif } |
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return 1; } |
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static int kgdb_reenter_check(struct kgdb_state *ks) { unsigned long addr; if (atomic_read(&kgdb_active) != raw_smp_processor_id()) return 0; /* Panic on recursive debugger calls: */ exception_level++; addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); |
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dbg_deactivate_sw_breakpoints(); |
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/* * If the break point removed ok at the place exception * occurred, try to recover and print a warning to the end * user because the user planted a breakpoint in a place that * KGDB needs in order to function. */ |
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if (dbg_remove_sw_break(addr) == 0) { |
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exception_level = 0; kgdb_skipexception(ks->ex_vector, ks->linux_regs); |
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dbg_activate_sw_breakpoints(); |
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printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx ", addr); |
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WARN_ON_ONCE(1); return 1; } |
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dbg_remove_all_break(); |
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kgdb_skipexception(ks->ex_vector, ks->linux_regs); if (exception_level > 1) { dump_stack(); panic("Recursive entry to debugger"); } printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed "); |
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#ifdef CONFIG_KGDB_KDB /* Allow kdb to debug itself one level */ return 0; #endif |
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dump_stack(); panic("Recursive entry to debugger"); return 1; } |
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static void dbg_touch_watchdogs(void) { touch_softlockup_watchdog_sync(); clocksource_touch_watchdog(); |
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rcu_cpu_stall_reset(); |
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} |
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static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs, int exception_state) |
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{ |
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unsigned long flags; |
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int sstep_tries = 100; |
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int error; |
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int cpu; |
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int trace_on = 0; |
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int online_cpus = num_online_cpus(); |
c1bb9a9c1 debug_core: disab... |
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|
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kgdb_info[ks->cpu].enter_kgdb++; kgdb_info[ks->cpu].exception_state |= exception_state; if (exception_state == DCPU_WANT_MASTER) atomic_inc(&masters_in_kgdb); else atomic_inc(&slaves_in_kgdb); |
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if (arch_kgdb_ops.disable_hw_break) arch_kgdb_ops.disable_hw_break(regs); |
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|
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acquirelock: /* * Interrupts will be restored by the 'trap return' code, except when * single stepping. */ local_irq_save(flags); |
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cpu = ks->cpu; kgdb_info[cpu].debuggerinfo = regs; kgdb_info[cpu].task = current; |
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kgdb_info[cpu].ret_state = 0; kgdb_info[cpu].irq_depth = hardirq_count() >> HARDIRQ_SHIFT; |
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|
dfee3a7b9 debug_core: refac... |
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/* Make sure the above info reaches the primary CPU */ smp_mb(); if (exception_level == 1) { if (raw_spin_trylock(&dbg_master_lock)) atomic_xchg(&kgdb_active, cpu); |
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goto cpu_master_loop; |
dfee3a7b9 debug_core: refac... |
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} |
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|
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/* |
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* CPU will loop if it is a slave or request to become a kgdb * master cpu and acquire the kgdb_active lock: |
dc7d55270 kgdb: core |
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*/ |
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while (1) { |
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cpu_loop: if (kgdb_info[cpu].exception_state & DCPU_NEXT_MASTER) { kgdb_info[cpu].exception_state &= ~DCPU_NEXT_MASTER; goto cpu_master_loop; } else if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) { |
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if (raw_spin_trylock(&dbg_master_lock)) { atomic_xchg(&kgdb_active, cpu); |
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break; |
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} |
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} else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) { |
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if (!raw_spin_is_locked(&dbg_slave_lock)) |
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goto return_normal; } else { return_normal: /* Return to normal operation by executing any * hw breakpoint fixup. */ if (arch_kgdb_ops.correct_hw_break) arch_kgdb_ops.correct_hw_break(); |
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if (trace_on) tracing_on(); |
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kgdb_info[cpu].exception_state &= ~(DCPU_WANT_MASTER | DCPU_IS_SLAVE); kgdb_info[cpu].enter_kgdb--; smp_mb__before_atomic_dec(); atomic_dec(&slaves_in_kgdb); |
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dbg_touch_watchdogs(); |
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local_irq_restore(flags); return 0; } |
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cpu_relax(); |
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} |
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/* |
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* For single stepping, try to only enter on the processor |
25985edce Fix common misspe... |
532 |
* that was single stepping. To guard against a deadlock, the |
028e7b175 kgdb: allow for c... |
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* kernel will only try for the value of sstep_tries before * giving up and continuing on. |
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*/ if (atomic_read(&kgdb_cpu_doing_single_step) != -1 && |
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(kgdb_info[cpu].task && kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) { |
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atomic_set(&kgdb_active, -1); |
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raw_spin_unlock(&dbg_master_lock); |
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dbg_touch_watchdogs(); |
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local_irq_restore(flags); goto acquirelock; } if (!kgdb_io_ready(1)) { |
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kgdb_info[cpu].ret_state = 1; |
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goto kgdb_restore; /* No I/O connection, resume the system */ |
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} /* * Don't enter if we have hit a removed breakpoint. */ if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) goto kgdb_restore; /* Call the I/O driver's pre_exception routine */ |
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if (dbg_io_ops->pre_exception) dbg_io_ops->pre_exception(); |
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|
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/* * Get the passive CPU lock which will hold all the non-primary * CPU in a spin state while the debugger is active */ |
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if (!kgdb_single_step) raw_spin_lock(&dbg_slave_lock); |
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|
56fb70932 kgdb: fix SMP NMI... |
569 570 |
#ifdef CONFIG_SMP /* Signal the other CPUs to enter kgdb_wait() */ |
d7161a653 kgdb, x86, arm, m... |
571 |
if ((!kgdb_single_step) && kgdb_do_roundup) |
56fb70932 kgdb: fix SMP NMI... |
572 573 |
kgdb_roundup_cpus(flags); #endif |
dc7d55270 kgdb: core |
574 575 576 |
/* * Wait for the other CPUs to be notified and be waiting for us: */ |
dfee3a7b9 debug_core: refac... |
577 578 579 |
while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) != online_cpus) cpu_relax(); |
dc7d55270 kgdb: core |
580 581 582 583 584 |
/* * At this point the primary processor is completely * in the debugger and all secondary CPUs are quiescent */ |
dcc787112 kgdb: core change... |
585 |
dbg_deactivate_sw_breakpoints(); |
dc7d55270 kgdb: core |
586 |
kgdb_single_step = 0; |
d7161a653 kgdb, x86, arm, m... |
587 |
kgdb_contthread = current; |
dc7d55270 kgdb: core |
588 |
exception_level = 0; |
4da75b9ce kgdb: Turn off tr... |
589 590 591 |
trace_on = tracing_is_on(); if (trace_on) tracing_off(); |
dc7d55270 kgdb: core |
592 |
|
dcc787112 kgdb: core change... |
593 594 595 596 597 |
while (1) { cpu_master_loop: if (dbg_kdb_mode) { kgdb_connected = 1; error = kdb_stub(ks); |
3fa43aba0 debug_core,kdb: f... |
598 599 |
if (error == -1) continue; |
b0679c63d debug_core,kdb: f... |
600 |
kgdb_connected = 0; |
dcc787112 kgdb: core change... |
601 602 603 604 605 606 |
} else { error = gdb_serial_stub(ks); } if (error == DBG_PASS_EVENT) { dbg_kdb_mode = !dbg_kdb_mode; |
dcc787112 kgdb: core change... |
607 |
} else if (error == DBG_SWITCH_CPU_EVENT) { |
495363d38 kdb,debug_core: a... |
608 609 |
kgdb_info[dbg_switch_cpu].exception_state |= DCPU_NEXT_MASTER; |
dcc787112 kgdb: core change... |
610 611 612 613 614 615 |
goto cpu_loop; } else { kgdb_info[cpu].ret_state = error; break; } } |
dc7d55270 kgdb: core |
616 617 |
/* Call the I/O driver's post_exception routine */ |
53197fc49 Separate the gdbs... |
618 619 |
if (dbg_io_ops->post_exception) dbg_io_ops->post_exception(); |
dc7d55270 kgdb: core |
620 |
|
d7161a653 kgdb, x86, arm, m... |
621 |
if (!kgdb_single_step) { |
dfee3a7b9 debug_core: refac... |
622 623 624 625 |
raw_spin_unlock(&dbg_slave_lock); /* Wait till all the CPUs have quit from the debugger. */ while (kgdb_do_roundup && atomic_read(&slaves_in_kgdb)) cpu_relax(); |
dc7d55270 kgdb: core |
626 627 628 |
} kgdb_restore: |
028e7b175 kgdb: allow for c... |
629 630 631 632 633 634 635 |
if (atomic_read(&kgdb_cpu_doing_single_step) != -1) { int sstep_cpu = atomic_read(&kgdb_cpu_doing_single_step); if (kgdb_info[sstep_cpu].task) kgdb_sstep_pid = kgdb_info[sstep_cpu].task->pid; else kgdb_sstep_pid = 0; } |
c1bb9a9c1 debug_core: disab... |
636 637 |
if (arch_kgdb_ops.correct_hw_break) arch_kgdb_ops.correct_hw_break(); |
4da75b9ce kgdb: Turn off tr... |
638 639 |
if (trace_on) tracing_on(); |
dfee3a7b9 debug_core: refac... |
640 641 642 643 644 645 |
kgdb_info[cpu].exception_state &= ~(DCPU_WANT_MASTER | DCPU_IS_SLAVE); kgdb_info[cpu].enter_kgdb--; smp_mb__before_atomic_dec(); atomic_dec(&masters_in_kgdb); |
dc7d55270 kgdb: core |
646 647 |
/* Free kgdb_active */ atomic_set(&kgdb_active, -1); |
dfee3a7b9 debug_core: refac... |
648 |
raw_spin_unlock(&dbg_master_lock); |
16cdc628c debug_core: move ... |
649 |
dbg_touch_watchdogs(); |
dc7d55270 kgdb: core |
650 |
local_irq_restore(flags); |
dcc787112 kgdb: core change... |
651 |
return kgdb_info[cpu].ret_state; |
dc7d55270 kgdb: core |
652 |
} |
62fae3121 kgdb: eliminate k... |
653 654 655 656 657 658 659 660 661 662 663 664 |
/* * kgdb_handle_exception() - main entry point from a kernel exception * * Locking hierarchy: * interface locks, if any (begin_session) * kgdb lock (kgdb_active) */ int kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) { struct kgdb_state kgdb_var; struct kgdb_state *ks = &kgdb_var; |
62fae3121 kgdb: eliminate k... |
665 666 667 668 |
ks->cpu = raw_smp_processor_id(); ks->ex_vector = evector; ks->signo = signo; |
62fae3121 kgdb: eliminate k... |
669 670 671 672 673 674 |
ks->err_code = ecode; ks->kgdb_usethreadid = 0; ks->linux_regs = regs; if (kgdb_reenter_check(ks)) return 0; /* Ouch, double exception ! */ |
dfee3a7b9 debug_core: refac... |
675 676 677 678 |
if (kgdb_info[ks->cpu].enter_kgdb != 0) return 0; return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER); |
62fae3121 kgdb: eliminate k... |
679 |
} |
dc7d55270 kgdb: core |
680 681 682 |
int kgdb_nmicallback(int cpu, void *regs) { #ifdef CONFIG_SMP |
62fae3121 kgdb: eliminate k... |
683 684 685 686 687 688 |
struct kgdb_state kgdb_var; struct kgdb_state *ks = &kgdb_var; memset(ks, 0, sizeof(struct kgdb_state)); ks->cpu = cpu; ks->linux_regs = regs; |
dfee3a7b9 debug_core: refac... |
689 690 691 |
if (kgdb_info[ks->cpu].enter_kgdb == 0 && raw_spin_is_locked(&dbg_master_lock)) { kgdb_cpu_enter(ks, regs, DCPU_IS_SLAVE); |
dc7d55270 kgdb: core |
692 693 694 695 696 |
return 0; } #endif return 1; } |
aabdc3b8c kgdb: sparse fix |
697 698 |
static void kgdb_console_write(struct console *co, const char *s, unsigned count) |
dc7d55270 kgdb: core |
699 700 701 702 703 |
{ unsigned long flags; /* If we're debugging, or KGDB has not connected, don't try * and print. */ |
dcc787112 kgdb: core change... |
704 |
if (!kgdb_connected || atomic_read(&kgdb_active) != -1 || dbg_kdb_mode) |
dc7d55270 kgdb: core |
705 706 707 |
return; local_irq_save(flags); |
53197fc49 Separate the gdbs... |
708 |
gdbstub_msg_write(s, count); |
dc7d55270 kgdb: core |
709 710 711 712 713 714 715 716 717 718 719 |
local_irq_restore(flags); } static struct console kgdbcons = { .name = "kgdb", .write = kgdb_console_write, .flags = CON_PRINTBUFFER | CON_ENABLED, .index = -1, }; #ifdef CONFIG_MAGIC_SYSRQ |
1495cc9df Input: sysrq - dr... |
720 |
static void sysrq_handle_dbg(int key) |
dc7d55270 kgdb: core |
721 |
{ |
53197fc49 Separate the gdbs... |
722 |
if (!dbg_io_ops) { |
dc7d55270 kgdb: core |
723 724 725 726 |
printk(KERN_CRIT "ERROR: No KGDB I/O module available "); return; } |
dcc787112 kgdb: core change... |
727 728 729 730 731 732 |
if (!kgdb_connected) { #ifdef CONFIG_KGDB_KDB if (!dbg_kdb_mode) printk(KERN_CRIT "KGDB or $3#33 for KDB "); #else |
dc7d55270 kgdb: core |
733 734 |
printk(KERN_CRIT "Entering KGDB "); |
dcc787112 kgdb: core change... |
735 736 |
#endif } |
dc7d55270 kgdb: core |
737 738 739 |
kgdb_breakpoint(); } |
53197fc49 Separate the gdbs... |
740 741 |
static struct sysrq_key_op sysrq_dbg_op = { .handler = sysrq_handle_dbg, |
364b5b7b1 sysrq, intel_fb: ... |
742 743 |
.help_msg = "debug(G)", .action_msg = "DEBUG", |
dc7d55270 kgdb: core |
744 745 |
}; #endif |
4402c153c kdb,debug_core: A... |
746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 |
static int kgdb_panic_event(struct notifier_block *self, unsigned long val, void *data) { if (dbg_kdb_mode) kdb_printf("PANIC: %s ", (char *)data); kgdb_breakpoint(); return NOTIFY_DONE; } static struct notifier_block kgdb_panic_event_nb = { .notifier_call = kgdb_panic_event, .priority = INT_MAX, }; |
0b4b3827d x86, kgdb, init: ... |
761 762 763 764 765 766 767 768 769 770 771 |
void __weak kgdb_arch_late(void) { } void __init dbg_late_init(void) { dbg_is_early = false; if (kgdb_io_module_registered) kgdb_arch_late(); kdb_init(KDB_INIT_FULL); } |
dc7d55270 kgdb: core |
772 773 774 775 776 |
static void kgdb_register_callbacks(void) { if (!kgdb_io_module_registered) { kgdb_io_module_registered = 1; kgdb_arch_init(); |
0b4b3827d x86, kgdb, init: ... |
777 778 |
if (!dbg_is_early) kgdb_arch_late(); |
4402c153c kdb,debug_core: A... |
779 780 |
atomic_notifier_chain_register(&panic_notifier_list, &kgdb_panic_event_nb); |
dc7d55270 kgdb: core |
781 |
#ifdef CONFIG_MAGIC_SYSRQ |
53197fc49 Separate the gdbs... |
782 |
register_sysrq_key('g', &sysrq_dbg_op); |
dc7d55270 kgdb: core |
783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 |
#endif if (kgdb_use_con && !kgdb_con_registered) { register_console(&kgdbcons); kgdb_con_registered = 1; } } } static void kgdb_unregister_callbacks(void) { /* * When this routine is called KGDB should unregister from the * panic handler and clean up, making sure it is not handling any * break exceptions at the time. */ if (kgdb_io_module_registered) { kgdb_io_module_registered = 0; |
4402c153c kdb,debug_core: A... |
800 801 |
atomic_notifier_chain_unregister(&panic_notifier_list, &kgdb_panic_event_nb); |
dc7d55270 kgdb: core |
802 803 |
kgdb_arch_exit(); #ifdef CONFIG_MAGIC_SYSRQ |
53197fc49 Separate the gdbs... |
804 |
unregister_sysrq_key('g', &sysrq_dbg_op); |
dc7d55270 kgdb: core |
805 806 807 808 809 810 811 |
#endif if (kgdb_con_registered) { unregister_console(&kgdbcons); kgdb_con_registered = 0; } } } |
1cee5e35f kgdb: Add the abi... |
812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 |
/* * There are times a tasklet needs to be used vs a compiled in * break point so as to cause an exception outside a kgdb I/O module, * such as is the case with kgdboe, where calling a breakpoint in the * I/O driver itself would be fatal. */ static void kgdb_tasklet_bpt(unsigned long ing) { kgdb_breakpoint(); atomic_set(&kgdb_break_tasklet_var, 0); } static DECLARE_TASKLET(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt, 0); void kgdb_schedule_breakpoint(void) { if (atomic_read(&kgdb_break_tasklet_var) || atomic_read(&kgdb_active) != -1 || atomic_read(&kgdb_setting_breakpoint)) return; atomic_inc(&kgdb_break_tasklet_var); tasklet_schedule(&kgdb_tasklet_breakpoint); } EXPORT_SYMBOL_GPL(kgdb_schedule_breakpoint); |
dc7d55270 kgdb: core |
836 837 838 839 840 841 842 843 844 845 |
static void kgdb_initial_breakpoint(void) { kgdb_break_asap = 0; printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb... "); kgdb_breakpoint(); } /** |
737a460f2 kgdb: fix several... |
846 |
* kgdb_register_io_module - register KGDB IO module |
53197fc49 Separate the gdbs... |
847 |
* @new_dbg_io_ops: the io ops vector |
dc7d55270 kgdb: core |
848 849 850 |
* * Register it with the KGDB core. */ |
53197fc49 Separate the gdbs... |
851 |
int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops) |
dc7d55270 kgdb: core |
852 853 854 855 |
{ int err; spin_lock(&kgdb_registration_lock); |
53197fc49 Separate the gdbs... |
856 |
if (dbg_io_ops) { |
dc7d55270 kgdb: core |
857 858 859 860 861 862 863 |
spin_unlock(&kgdb_registration_lock); printk(KERN_ERR "kgdb: Another I/O driver is already " "registered with KGDB. "); return -EBUSY; } |
53197fc49 Separate the gdbs... |
864 865 |
if (new_dbg_io_ops->init) { err = new_dbg_io_ops->init(); |
dc7d55270 kgdb: core |
866 867 868 869 870 |
if (err) { spin_unlock(&kgdb_registration_lock); return err; } } |
53197fc49 Separate the gdbs... |
871 |
dbg_io_ops = new_dbg_io_ops; |
dc7d55270 kgdb: core |
872 873 874 875 876 |
spin_unlock(&kgdb_registration_lock); printk(KERN_INFO "kgdb: Registered I/O driver %s. ", |
53197fc49 Separate the gdbs... |
877 |
new_dbg_io_ops->name); |
dc7d55270 kgdb: core |
878 879 880 881 882 883 884 885 886 887 888 889 890 |
/* Arm KGDB now. */ kgdb_register_callbacks(); if (kgdb_break_asap) kgdb_initial_breakpoint(); return 0; } EXPORT_SYMBOL_GPL(kgdb_register_io_module); /** * kkgdb_unregister_io_module - unregister KGDB IO module |
53197fc49 Separate the gdbs... |
891 |
* @old_dbg_io_ops: the io ops vector |
dc7d55270 kgdb: core |
892 893 894 |
* * Unregister it with the KGDB core. */ |
53197fc49 Separate the gdbs... |
895 |
void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops) |
dc7d55270 kgdb: core |
896 897 898 899 900 901 902 903 904 905 |
{ BUG_ON(kgdb_connected); /* * KGDB is no longer able to communicate out, so * unregister our callbacks and reset state. */ kgdb_unregister_callbacks(); spin_lock(&kgdb_registration_lock); |
53197fc49 Separate the gdbs... |
906 907 |
WARN_ON_ONCE(dbg_io_ops != old_dbg_io_ops); dbg_io_ops = NULL; |
dc7d55270 kgdb: core |
908 909 910 911 912 913 |
spin_unlock(&kgdb_registration_lock); printk(KERN_INFO "kgdb: Unregistered I/O driver %s, debugger disabled. ", |
53197fc49 Separate the gdbs... |
914 |
old_dbg_io_ops->name); |
dc7d55270 kgdb: core |
915 916 |
} EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); |
dcc787112 kgdb: core change... |
917 918 919 |
int dbg_io_get_char(void) { int ret = dbg_io_ops->read_char(); |
f5316b4ae kgdb,8250,pl011: ... |
920 921 |
if (ret == NO_POLL_CHAR) return -1; |
dcc787112 kgdb: core change... |
922 923 924 925 926 927 |
if (!dbg_kdb_mode) return ret; if (ret == 127) return 8; return ret; } |
dc7d55270 kgdb: core |
928 929 930 931 932 933 934 935 936 937 |
/** * kgdb_breakpoint - generate breakpoint exception * * This function will generate a breakpoint exception. It is used at the * beginning of a program to sync up with a debugger and can be used * otherwise as a quick means to stop program execution and "break" into * the debugger. */ void kgdb_breakpoint(void) { |
ae6bf53e0 kgdb: use atomic_... |
938 |
atomic_inc(&kgdb_setting_breakpoint); |
dc7d55270 kgdb: core |
939 940 941 |
wmb(); /* Sync point before breakpoint */ arch_kgdb_breakpoint(); wmb(); /* Sync point after breakpoint */ |
ae6bf53e0 kgdb: use atomic_... |
942 |
atomic_dec(&kgdb_setting_breakpoint); |
dc7d55270 kgdb: core |
943 944 945 946 947 948 |
} EXPORT_SYMBOL_GPL(kgdb_breakpoint); static int __init opt_kgdb_wait(char *str) { kgdb_break_asap = 1; |
dcc787112 kgdb: core change... |
949 |
kdb_init(KDB_INIT_EARLY); |
dc7d55270 kgdb: core |
950 951 952 953 954 955 956 |
if (kgdb_io_module_registered) kgdb_initial_breakpoint(); return 0; } early_param("kgdbwait", opt_kgdb_wait); |