Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kdb,debug_core: adjust master cpu switch logic against new debug_core locking
debug_core: refactor locking for master/slave cpus
x86,kgdb: remove unnecessary call to kgdb_correct_hw_break()
debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()
kdb,kgdb: fix sparse fixups
kdb: Fix oops in kdb_unregister
kdb,ftdump: Remove reference to internal kdb include
kdb: Allow kernel loadable modules to add kdb shell functions
debug_core: stop rcu warnings on kernel resume
debug_core: move all watch dog syncs to a single function
x86,kgdb: fix debugger hw breakpoint test regression in 2.6.35
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 852b819..d81cfeb 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -477,8 +477,6 @@
raw_smp_processor_id());
}
- kgdb_correct_hw_break();
-
return 0;
}
@@ -621,7 +619,12 @@
static void kgdb_hw_overflow_handler(struct perf_event *event, int nmi,
struct perf_sample_data *data, struct pt_regs *regs)
{
- kgdb_ll_trap(DIE_DEBUG, "debug", regs, 0, 0, SIGTRAP);
+ struct task_struct *tsk = current;
+ int i;
+
+ for (i = 0; i < 4; i++)
+ if (breakinfo[i].enabled)
+ tsk->thread.debugreg6 |= (DR_TRAP0 << i);
}
void kgdb_arch_late(void)
@@ -644,7 +647,7 @@
if (breakinfo[i].pev)
continue;
breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL);
- if (IS_ERR(breakinfo[i].pev)) {
+ if (IS_ERR((void * __force)breakinfo[i].pev)) {
printk(KERN_ERR "kgdb: Could not allocate hw"
"breakpoints\nDisabling the kernel debugger\n");
breakinfo[i].pev = NULL;
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c
index 39f9a1a..d4b711c 100644
--- a/drivers/serial/kgdboc.c
+++ b/drivers/serial/kgdboc.c
@@ -243,7 +243,7 @@
#ifdef CONFIG_KGDB_SERIAL_CONSOLE
/* This is only available if kgdboc is a built in for early debugging */
-int __init kgdboc_early_init(char *opt)
+static int __init kgdboc_early_init(char *opt)
{
/* save the first character of the config string because the
* init routine can destroy it.
diff --git a/include/linux/kdb.h b/include/linux/kdb.h
index ea6e524..aadff7c 100644
--- a/include/linux/kdb.h
+++ b/include/linux/kdb.h
@@ -28,6 +28,41 @@
extern int kdb_initial_cpu;
extern atomic_t kdb_event;
+/* Types and messages used for dynamically added kdb shell commands */
+
+#define KDB_MAXARGS 16 /* Maximum number of arguments to a function */
+
+typedef enum {
+ KDB_REPEAT_NONE = 0, /* Do not repeat this command */
+ KDB_REPEAT_NO_ARGS, /* Repeat the command without arguments */
+ KDB_REPEAT_WITH_ARGS, /* Repeat the command including its arguments */
+} kdb_repeat_t;
+
+typedef int (*kdb_func_t)(int, const char **);
+
+/* KDB return codes from a command or internal kdb function */
+#define KDB_NOTFOUND (-1)
+#define KDB_ARGCOUNT (-2)
+#define KDB_BADWIDTH (-3)
+#define KDB_BADRADIX (-4)
+#define KDB_NOTENV (-5)
+#define KDB_NOENVVALUE (-6)
+#define KDB_NOTIMP (-7)
+#define KDB_ENVFULL (-8)
+#define KDB_ENVBUFFULL (-9)
+#define KDB_TOOMANYBPT (-10)
+#define KDB_TOOMANYDBREGS (-11)
+#define KDB_DUPBPT (-12)
+#define KDB_BPTNOTFOUND (-13)
+#define KDB_BADMODE (-14)
+#define KDB_BADINT (-15)
+#define KDB_INVADDRFMT (-16)
+#define KDB_BADREG (-17)
+#define KDB_BADCPUNUM (-18)
+#define KDB_BADLENGTH (-19)
+#define KDB_NOBP (-20)
+#define KDB_BADADDR (-21)
+
/*
* kdb_diemsg
*
@@ -104,10 +139,26 @@
/* kdb access to register set for stack dumping */
extern struct pt_regs *kdb_current_regs;
+#ifdef CONFIG_KALLSYMS
+extern const char *kdb_walk_kallsyms(loff_t *pos);
+#else /* ! CONFIG_KALLSYMS */
+static inline const char *kdb_walk_kallsyms(loff_t *pos)
+{
+ return NULL;
+}
+#endif /* ! CONFIG_KALLSYMS */
+/* Dynamic kdb shell command registration */
+extern int kdb_register(char *, kdb_func_t, char *, char *, short);
+extern int kdb_register_repeat(char *, kdb_func_t, char *, char *,
+ short, kdb_repeat_t);
+extern int kdb_unregister(char *);
#else /* ! CONFIG_KGDB_KDB */
#define kdb_printf(...)
#define kdb_init(x)
+#define kdb_register(...)
+#define kdb_register_repeat(...)
+#define kdb_uregister(x)
#endif /* CONFIG_KGDB_KDB */
enum {
KDB_NOT_INITIALIZED,
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index de407c7..fec596d 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -47,6 +47,7 @@
#include <linux/pid.h>
#include <linux/smp.h>
#include <linux/mm.h>
+#include <linux/rcupdate.h>
#include <asm/cacheflush.h>
#include <asm/byteorder.h>
@@ -109,13 +110,15 @@
*/
atomic_t kgdb_active = ATOMIC_INIT(-1);
EXPORT_SYMBOL_GPL(kgdb_active);
+static DEFINE_RAW_SPINLOCK(dbg_master_lock);
+static DEFINE_RAW_SPINLOCK(dbg_slave_lock);
/*
* We use NR_CPUs not PERCPU, in case kgdb is used to debug early
* bootup code (which might not have percpu set up yet):
*/
-static atomic_t passive_cpu_wait[NR_CPUS];
-static atomic_t cpu_in_kgdb[NR_CPUS];
+static atomic_t masters_in_kgdb;
+static atomic_t slaves_in_kgdb;
static atomic_t kgdb_break_tasklet_var;
atomic_t kgdb_setting_breakpoint;
@@ -457,26 +460,32 @@
return 1;
}
-static void dbg_cpu_switch(int cpu, int next_cpu)
+static void dbg_touch_watchdogs(void)
{
- /* Mark the cpu we are switching away from as a slave when it
- * holds the kgdb_active token. This must be done so that the
- * that all the cpus wait in for the debug core will not enter
- * again as the master. */
- if (cpu == atomic_read(&kgdb_active)) {
- kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE;
- kgdb_info[cpu].exception_state &= ~DCPU_WANT_MASTER;
- }
- kgdb_info[next_cpu].exception_state |= DCPU_NEXT_MASTER;
+ touch_softlockup_watchdog_sync();
+ clocksource_touch_watchdog();
+ rcu_cpu_stall_reset();
}
-static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
+static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
+ int exception_state)
{
unsigned long flags;
int sstep_tries = 100;
int error;
- int i, cpu;
+ int cpu;
int trace_on = 0;
+ int online_cpus = num_online_cpus();
+
+ 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);
+ kgdb_disable_hw_debug(ks->linux_regs);
+
acquirelock:
/*
* Interrupts will be restored by the 'trap return' code, except when
@@ -489,14 +498,15 @@
kgdb_info[cpu].task = current;
kgdb_info[cpu].ret_state = 0;
kgdb_info[cpu].irq_depth = hardirq_count() >> HARDIRQ_SHIFT;
- /*
- * Make sure the above info reaches the primary CPU before
- * our cpu_in_kgdb[] flag setting does:
- */
- atomic_inc(&cpu_in_kgdb[cpu]);
- if (exception_level == 1)
+ /* 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);
goto cpu_master_loop;
+ }
/*
* CPU will loop if it is a slave or request to become a kgdb
@@ -508,10 +518,12 @@
kgdb_info[cpu].exception_state &= ~DCPU_NEXT_MASTER;
goto cpu_master_loop;
} else if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) {
- if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu)
+ if (raw_spin_trylock(&dbg_master_lock)) {
+ atomic_xchg(&kgdb_active, cpu);
break;
+ }
} else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) {
- if (!atomic_read(&passive_cpu_wait[cpu]))
+ if (!raw_spin_is_locked(&dbg_slave_lock))
goto return_normal;
} else {
return_normal:
@@ -522,9 +534,12 @@
arch_kgdb_ops.correct_hw_break();
if (trace_on)
tracing_on();
- atomic_dec(&cpu_in_kgdb[cpu]);
- touch_softlockup_watchdog_sync();
- clocksource_touch_watchdog();
+ 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);
+ dbg_touch_watchdogs();
local_irq_restore(flags);
return 0;
}
@@ -541,8 +556,8 @@
(kgdb_info[cpu].task &&
kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) {
atomic_set(&kgdb_active, -1);
- touch_softlockup_watchdog_sync();
- clocksource_touch_watchdog();
+ raw_spin_unlock(&dbg_master_lock);
+ dbg_touch_watchdogs();
local_irq_restore(flags);
goto acquirelock;
@@ -563,16 +578,12 @@
if (dbg_io_ops->pre_exception)
dbg_io_ops->pre_exception();
- kgdb_disable_hw_debug(ks->linux_regs);
-
/*
* Get the passive CPU lock which will hold all the non-primary
* CPU in a spin state while the debugger is active
*/
- if (!kgdb_single_step) {
- for (i = 0; i < NR_CPUS; i++)
- atomic_inc(&passive_cpu_wait[i]);
- }
+ if (!kgdb_single_step)
+ raw_spin_lock(&dbg_slave_lock);
#ifdef CONFIG_SMP
/* Signal the other CPUs to enter kgdb_wait() */
@@ -583,10 +594,9 @@
/*
* Wait for the other CPUs to be notified and be waiting for us:
*/
- for_each_online_cpu(i) {
- while (kgdb_do_roundup && !atomic_read(&cpu_in_kgdb[i]))
- cpu_relax();
- }
+ while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) +
+ atomic_read(&slaves_in_kgdb)) != online_cpus)
+ cpu_relax();
/*
* At this point the primary processor is completely
@@ -615,7 +625,8 @@
if (error == DBG_PASS_EVENT) {
dbg_kdb_mode = !dbg_kdb_mode;
} else if (error == DBG_SWITCH_CPU_EVENT) {
- dbg_cpu_switch(cpu, dbg_switch_cpu);
+ kgdb_info[dbg_switch_cpu].exception_state |=
+ DCPU_NEXT_MASTER;
goto cpu_loop;
} else {
kgdb_info[cpu].ret_state = error;
@@ -627,24 +638,11 @@
if (dbg_io_ops->post_exception)
dbg_io_ops->post_exception();
- atomic_dec(&cpu_in_kgdb[ks->cpu]);
-
if (!kgdb_single_step) {
- for (i = NR_CPUS-1; i >= 0; i--)
- atomic_dec(&passive_cpu_wait[i]);
- /*
- * Wait till all the CPUs have quit from the debugger,
- * but allow a CPU that hit an exception and is
- * waiting to become the master to remain in the debug
- * core.
- */
- for_each_online_cpu(i) {
- while (kgdb_do_roundup &&
- atomic_read(&cpu_in_kgdb[i]) &&
- !(kgdb_info[i].exception_state &
- DCPU_WANT_MASTER))
- cpu_relax();
- }
+ 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();
}
kgdb_restore:
@@ -655,12 +653,20 @@
else
kgdb_sstep_pid = 0;
}
+ if (arch_kgdb_ops.correct_hw_break)
+ arch_kgdb_ops.correct_hw_break();
if (trace_on)
tracing_on();
+
+ 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);
/* Free kgdb_active */
atomic_set(&kgdb_active, -1);
- touch_softlockup_watchdog_sync();
- clocksource_touch_watchdog();
+ raw_spin_unlock(&dbg_master_lock);
+ dbg_touch_watchdogs();
local_irq_restore(flags);
return kgdb_info[cpu].ret_state;
@@ -678,7 +684,6 @@
{
struct kgdb_state kgdb_var;
struct kgdb_state *ks = &kgdb_var;
- int ret;
ks->cpu = raw_smp_processor_id();
ks->ex_vector = evector;
@@ -689,11 +694,10 @@
if (kgdb_reenter_check(ks))
return 0; /* Ouch, double exception ! */
- kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER;
- ret = kgdb_cpu_enter(ks, regs);
- kgdb_info[ks->cpu].exception_state &= ~(DCPU_WANT_MASTER |
- DCPU_IS_SLAVE);
- return ret;
+ if (kgdb_info[ks->cpu].enter_kgdb != 0)
+ return 0;
+
+ return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
}
int kgdb_nmicallback(int cpu, void *regs)
@@ -706,12 +710,9 @@
ks->cpu = cpu;
ks->linux_regs = regs;
- if (!atomic_read(&cpu_in_kgdb[cpu]) &&
- atomic_read(&kgdb_active) != -1 &&
- atomic_read(&kgdb_active) != cpu) {
- kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE;
- kgdb_cpu_enter(ks, regs);
- kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE;
+ if (kgdb_info[ks->cpu].enter_kgdb == 0 &&
+ raw_spin_is_locked(&dbg_master_lock)) {
+ kgdb_cpu_enter(ks, regs, DCPU_IS_SLAVE);
return 0;
}
#endif
diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index c5d753d..3494c28 100644
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -40,6 +40,7 @@
int exception_state;
int ret_state;
int irq_depth;
+ int enter_kgdb;
};
extern struct debuggerinfo_struct kgdb_info[];
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index bf6e827..dd0b1b7 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -86,7 +86,7 @@
}
/* Set initial kdb state variables */
KDB_STATE_CLEAR(KGDB_TRANS);
- kdb_initial_cpu = ks->cpu;
+ kdb_initial_cpu = atomic_read(&kgdb_active);
kdb_current_task = kgdb_info[ks->cpu].task;
kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
/* Remove any breakpoints as needed by kdb and clear single step */
@@ -105,7 +105,6 @@
ks->pass_exception = 1;
KDB_FLAG_SET(CATASTROPHIC);
}
- kdb_initial_cpu = ks->cpu;
if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
KDB_STATE_CLEAR(SSBPT);
KDB_STATE_CLEAR(DOING_SS);
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index c9b7f4f9..96fdaac 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -823,4 +823,4 @@
return r;
}
-
+EXPORT_SYMBOL_GPL(kdb_printf);
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index caf057a3..d7bda21 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1749,13 +1749,13 @@
int nextarg;
long offset;
+ if (raw_smp_processor_id() != kdb_initial_cpu) {
+ kdb_printf("go must execute on the entry cpu, "
+ "please use \"cpu %d\" and then execute go\n",
+ kdb_initial_cpu);
+ return KDB_BADCPUNUM;
+ }
if (argc == 1) {
- if (raw_smp_processor_id() != kdb_initial_cpu) {
- kdb_printf("go <address> must be issued from the "
- "initial cpu, do cpu %d first\n",
- kdb_initial_cpu);
- return KDB_ARGCOUNT;
- }
nextarg = 1;
diag = kdbgetaddrarg(argc, argv, &nextarg,
&addr, &offset, NULL);
@@ -2783,6 +2783,8 @@
return 0;
}
+EXPORT_SYMBOL_GPL(kdb_register_repeat);
+
/*
* kdb_register - Compatibility register function for commands that do
@@ -2805,6 +2807,7 @@
return kdb_register_repeat(cmd, func, usage, help, minlen,
KDB_REPEAT_NONE);
}
+EXPORT_SYMBOL_GPL(kdb_register);
/*
* kdb_unregister - This function is used to unregister a kernel
@@ -2823,7 +2826,7 @@
/*
* find the command.
*/
- for (i = 0, kp = kdb_commands; i < kdb_max_commands; i++, kp++) {
+ for_each_kdbcmd(kp, i) {
if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
kp->cmd_name = NULL;
return 0;
@@ -2833,6 +2836,7 @@
/* Couldn't find it. */
return 1;
}
+EXPORT_SYMBOL_GPL(kdb_unregister);
/* Initialize the kdb command table. */
static void __init kdb_inittab(void)
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index be775f7..35d69ed 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -15,29 +15,6 @@
#include <linux/kgdb.h>
#include "../debug_core.h"
-/* Kernel Debugger Error codes. Must not overlap with command codes. */
-#define KDB_NOTFOUND (-1)
-#define KDB_ARGCOUNT (-2)
-#define KDB_BADWIDTH (-3)
-#define KDB_BADRADIX (-4)
-#define KDB_NOTENV (-5)
-#define KDB_NOENVVALUE (-6)
-#define KDB_NOTIMP (-7)
-#define KDB_ENVFULL (-8)
-#define KDB_ENVBUFFULL (-9)
-#define KDB_TOOMANYBPT (-10)
-#define KDB_TOOMANYDBREGS (-11)
-#define KDB_DUPBPT (-12)
-#define KDB_BPTNOTFOUND (-13)
-#define KDB_BADMODE (-14)
-#define KDB_BADINT (-15)
-#define KDB_INVADDRFMT (-16)
-#define KDB_BADREG (-17)
-#define KDB_BADCPUNUM (-18)
-#define KDB_BADLENGTH (-19)
-#define KDB_NOBP (-20)
-#define KDB_BADADDR (-21)
-
/* Kernel Debugger Command codes. Must not overlap with error codes. */
#define KDB_CMD_GO (-1001)
#define KDB_CMD_CPU (-1002)
@@ -93,17 +70,6 @@
*/
#define KDB_MAXBPT 16
-/* Maximum number of arguments to a function */
-#define KDB_MAXARGS 16
-
-typedef enum {
- KDB_REPEAT_NONE = 0, /* Do not repeat this command */
- KDB_REPEAT_NO_ARGS, /* Repeat the command without arguments */
- KDB_REPEAT_WITH_ARGS, /* Repeat the command including its arguments */
-} kdb_repeat_t;
-
-typedef int (*kdb_func_t)(int, const char **);
-
/* Symbol table format returned by kallsyms. */
typedef struct __ksymtab {
unsigned long value; /* Address of symbol */
@@ -123,11 +89,6 @@
extern int kallsyms_symbol_complete(char *prefix_name, int max_len);
/* Exported Symbols for kernel loadable modules to use. */
-extern int kdb_register(char *, kdb_func_t, char *, char *, short);
-extern int kdb_register_repeat(char *, kdb_func_t, char *, char *,
- short, kdb_repeat_t);
-extern int kdb_unregister(char *);
-
extern int kdb_getarea_size(void *, unsigned long, size_t);
extern int kdb_putarea_size(unsigned long, void *, size_t);
@@ -144,6 +105,7 @@
extern int kdb_putword(unsigned long, unsigned long, size_t);
extern int kdbgetularg(const char *, unsigned long *);
+extern int kdbgetu64arg(const char *, u64 *);
extern char *kdbgetenv(const char *);
extern int kdbgetaddrarg(int, const char **, int*, unsigned long *,
long *, char **);
@@ -255,14 +217,6 @@
extern void kdb_print_nameval(const char *name, unsigned long val);
extern void kdb_send_sig_info(struct task_struct *p, struct siginfo *info);
extern void kdb_meminfo_proc_show(void);
-#ifdef CONFIG_KALLSYMS
-extern const char *kdb_walk_kallsyms(loff_t *pos);
-#else /* ! CONFIG_KALLSYMS */
-static inline const char *kdb_walk_kallsyms(loff_t *pos)
-{
- return NULL;
-}
-#endif /* ! CONFIG_KALLSYMS */
extern char *kdb_getstr(char *, size_t, char *);
/* Defines for kdb_symbol_print */
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index 7b8ecd7..3c5c5df 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -13,7 +13,6 @@
#include <linux/kdb.h>
#include <linux/ftrace.h>
-#include "../debug/kdb/kdb_private.h"
#include "trace.h"
#include "trace_output.h"
