diff options
Diffstat (limited to 'kernel/debug')
| -rw-r--r-- | kernel/debug/debug_core.c | 155 | ||||
| -rw-r--r-- | kernel/debug/debug_core.h | 1 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_bp.c | 2 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_debugger.c | 3 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_io.c | 2 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_main.c | 68 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_private.h | 41 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_support.c | 4 |
8 files changed, 103 insertions, 173 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 3c2d4972d235..cefd4a11f6d9 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 @@ static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { */ 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; @@ -206,18 +209,6 @@ int __weak kgdb_skipexception(int exception, struct pt_regs *regs) return 0; } -/** - * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. - * @regs: Current &struct pt_regs. - * - * This function will be called if the particular architecture must - * disable hardware debugging while it is processing gdb packets or - * handling exception. - */ -void __weak kgdb_disable_hw_debug(struct pt_regs *regs) -{ -} - /* * Some architectures need cache flushes when we set/clear a * breakpoint: @@ -457,26 +448,34 @@ static int kgdb_reenter_check(struct kgdb_state *ks) 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); + + if (arch_kgdb_ops.disable_hw_break) + arch_kgdb_ops.disable_hw_break(regs); + acquirelock: /* * Interrupts will be restored by the 'trap return' code, except when @@ -489,14 +488,15 @@ acquirelock: 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 +508,12 @@ cpu_loop: 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 +524,12 @@ return_normal: 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 +546,8 @@ return_normal: (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 +568,12 @@ return_normal: 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 +584,9 @@ return_normal: /* * 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 +615,8 @@ cpu_master_loop: 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 +628,11 @@ cpu_master_loop: 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 +643,20 @@ kgdb_restore: 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 +674,6 @@ 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; ks->cpu = raw_smp_processor_id(); ks->ex_vector = evector; @@ -689,11 +684,10 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) 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 +700,9 @@ int kgdb_nmicallback(int cpu, void *regs) 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 @@ -741,7 +732,7 @@ static struct console kgdbcons = { }; #ifdef CONFIG_MAGIC_SYSRQ -static void sysrq_handle_dbg(int key, struct tty_struct *tty) +static void sysrq_handle_dbg(int key) { if (!dbg_io_ops) { printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h index c5d753d80f67..3494c28a7e7a 100644 --- a/kernel/debug/debug_core.h +++ b/kernel/debug/debug_core.h @@ -40,6 +40,7 @@ struct debuggerinfo_struct { 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_bp.c b/kernel/debug/kdb/kdb_bp.c index 75bd9b3ebbb7..20059ef4459a 100644 --- a/kernel/debug/kdb/kdb_bp.c +++ b/kernel/debug/kdb/kdb_bp.c @@ -274,7 +274,6 @@ static int kdb_bp(int argc, const char **argv) int i, bpno; kdb_bp_t *bp, *bp_check; int diag; - int free; char *symname = NULL; long offset = 0ul; int nextarg; @@ -305,7 +304,6 @@ static int kdb_bp(int argc, const char **argv) /* * Find an empty bp structure to allocate */ - free = KDB_MAXBPT; for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT; bpno++, bp++) { if (bp->bp_free) break; diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c index bf6e8270e957..dd0b1b7dd02c 100644 --- a/kernel/debug/kdb/kdb_debugger.c +++ b/kernel/debug/kdb/kdb_debugger.c @@ -86,7 +86,7 @@ int kdb_stub(struct kgdb_state *ks) } /* 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 @@ int kdb_stub(struct kgdb_state *ks) 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 c9b7f4f90bba..96fdaac46a80 100644 --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -823,4 +823,4 @@ int kdb_printf(const char *fmt, ...) return r; } - +EXPORT_SYMBOL_GPL(kdb_printf); diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 28b844118bbd..37755d621924 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1127,7 +1127,7 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs, /* special case below */ } else { kdb_printf("\nEntering kdb (current=0x%p, pid %d) ", - kdb_current, kdb_current->pid); + kdb_current, kdb_current ? kdb_current->pid : 0); #if defined(CONFIG_SMP) kdb_printf("on processor %d ", raw_smp_processor_id()); #endif @@ -1749,13 +1749,13 @@ static int kdb_go(int argc, const char **argv) 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); @@ -1929,7 +1929,7 @@ static int kdb_sr(int argc, const char **argv) if (argc != 1) return KDB_ARGCOUNT; kdb_trap_printk++; - __handle_sysrq(*argv[1], NULL, 0); + __handle_sysrq(*argv[1], false); kdb_trap_printk--; return 0; @@ -2603,20 +2603,17 @@ static int kdb_summary(int argc, const char **argv) */ static int kdb_per_cpu(int argc, const char **argv) { - char buf[256], fmtstr[64]; - kdb_symtab_t symtab; - cpumask_t suppress = CPU_MASK_NONE; - int cpu, diag; - unsigned long addr, val, bytesperword = 0, whichcpu = ~0UL; + char fmtstr[64]; + int cpu, diag, nextarg = 1; + unsigned long addr, symaddr, val, bytesperword = 0, whichcpu = ~0UL; if (argc < 1 || argc > 3) return KDB_ARGCOUNT; - snprintf(buf, sizeof(buf), "per_cpu__%s", argv[1]); - if (!kdbgetsymval(buf, &symtab)) { - kdb_printf("%s is not a per_cpu variable\n", argv[1]); - return KDB_BADADDR; - } + diag = kdbgetaddrarg(argc, argv, &nextarg, &symaddr, NULL, NULL); + if (diag) + return diag; + if (argc >= 2) { diag = kdbgetularg(argv[2], &bytesperword); if (diag) @@ -2649,46 +2646,25 @@ static int kdb_per_cpu(int argc, const char **argv) #define KDB_PCU(cpu) 0 #endif #endif - for_each_online_cpu(cpu) { + if (KDB_FLAG(CMD_INTERRUPT)) + return 0; + if (whichcpu != ~0UL && whichcpu != cpu) continue; - addr = symtab.sym_start + KDB_PCU(cpu); + addr = symaddr + KDB_PCU(cpu); diag = kdb_getword(&val, addr, bytesperword); if (diag) { kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to " "read, diag=%d\n", cpu, addr, diag); continue; } -#ifdef CONFIG_SMP - if (!val) { - cpu_set(cpu, suppress); - continue; - } -#endif /* CONFIG_SMP */ kdb_printf("%5d ", cpu); kdb_md_line(fmtstr, addr, bytesperword == KDB_WORD_SIZE, 1, bytesperword, 1, 1, 0); } - if (cpus_weight(suppress) == 0) - return 0; - kdb_printf("Zero suppressed cpu(s):"); - for (cpu = first_cpu(suppress); cpu < num_possible_cpus(); - cpu = next_cpu(cpu, suppress)) { - kdb_printf(" %d", cpu); - if (cpu == num_possible_cpus() - 1 || - next_cpu(cpu, suppress) != cpu + 1) - continue; - while (cpu < num_possible_cpus() && - next_cpu(cpu, suppress) == cpu + 1) - ++cpu; - kdb_printf("-%d", cpu); - } - kdb_printf("\n"); - #undef KDB_PCU - return 0; } @@ -2783,6 +2759,8 @@ int kdb_register_repeat(char *cmd, return 0; } +EXPORT_SYMBOL_GPL(kdb_register_repeat); + /* * kdb_register - Compatibility register function for commands that do @@ -2805,6 +2783,7 @@ int kdb_register(char *cmd, 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 +2802,7 @@ int kdb_unregister(char *cmd) /* * 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 +2812,7 @@ int kdb_unregister(char *cmd) /* 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 c438f545a321..35d69ed1dfb5 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_next(char *prefix_name, int flag); 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_getword(unsigned long *, unsigned long, size_t); 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 **); @@ -255,7 +217,6 @@ extern void kdb_ps1(const struct task_struct *p); 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); -extern const char *kdb_walk_kallsyms(loff_t *pos); extern char *kdb_getstr(char *, size_t, char *); /* Defines for kdb_symbol_print */ diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c index 45344d5c53dd..6b2485dcb050 100644 --- a/kernel/debug/kdb/kdb_support.c +++ b/kernel/debug/kdb/kdb_support.c @@ -82,8 +82,8 @@ static char *kdb_name_table[100]; /* arbitrary size */ int kdbnearsym(unsigned long addr, kdb_symtab_t *symtab) { int ret = 0; - unsigned long symbolsize; - unsigned long offset; + unsigned long symbolsize = 0; + unsigned long offset = 0; #define knt1_size 128 /* must be >= kallsyms table size */ char *knt1 = NULL; |
