From f7030bbc446430ecd12c9ad02cf0ea94934e5f91 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Mon, 11 Oct 2010 10:20:14 -0500 Subject: kdb: Allow kernel loadable modules to add kdb shell functions In order to allow kernel modules to dynamically add a command to the kdb shell the kdb_register, kdb_register_repeat, kdb_unregister, and kdb_printf need to be exported as GPL symbols. Any kernel module that adds a dynamic kdb shell function should only need to include linux/kdb.h. Signed-off-by: Jason Wessel --- kernel/debug/kdb/kdb_io.c | 2 +- kernel/debug/kdb/kdb_main.c | 4 ++++ kernel/debug/kdb/kdb_private.h | 39 --------------------------------------- 3 files changed, 5 insertions(+), 40 deletions(-) (limited to 'kernel/debug/kdb') diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c index c9b7f4f90bb..96fdaac46a8 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 caf057a3de0..5448990a299 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -2783,6 +2783,8 @@ 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 +2807,7 @@ 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 @@ -2833,6 +2836,7 @@ 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 be775f7e81e..1921e6e4c0b 100644 --- a/kernel/debug/kdb/kdb_private.h +++ b/kernel/debug/kdb/kdb_private.h @@ -15,29 +15,6 @@ #include #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); -- cgit v1.2.3-70-g09d2 From 75d14edee5689716b55afe467acfc13206a31f95 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Mon, 11 Oct 2010 10:20:14 -0500 Subject: kdb: Fix oops in kdb_unregister Nothing should try to use kdb_commands directly as sometimes it is null. Instead, use the for_each_kdbcmd() iterator. This particular problem dates back to the initial kdb merge (2.6.35), but at that point nothing was dynamically unregistering commands from the kdb shell. Signed-off-by: Jason Wessel --- kernel/debug/kdb/kdb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/debug/kdb') diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 5448990a299..4226f32517d 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -2826,7 +2826,7 @@ 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; -- cgit v1.2.3-70-g09d2 From 91b152aa85bbcf076e269565394c31964f940371 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Mon, 23 Aug 2010 09:20:14 -0500 Subject: kdb,kgdb: fix sparse fixups Fix the following sparse warnings: kdb_main.c:328:5: warning: symbol 'kdbgetu64arg' was not declared. Should it be static? kgdboc.c:246:12: warning: symbol 'kgdboc_early_init' was not declared. Should it be static? kgdb.c:652:26: warning: incorrect type in argument 1 (different address spaces) kgdb.c:652:26: expected void const *ptr kgdb.c:652:26: got struct perf_event *[noderef] *pev The one in kgdb.c required the (void * __force) because of the return code from register_wide_hw_breakpoint looking like: return (void __percpu __force *)ERR_PTR(err); Signed-off-by: Jason Wessel --- arch/x86/kernel/kgdb.c | 2 +- drivers/serial/kgdboc.c | 2 +- include/linux/kdb.h | 8 ++++++++ kernel/debug/kdb/kdb_private.h | 9 +-------- 4 files changed, 11 insertions(+), 10 deletions(-) (limited to 'kernel/debug/kdb') diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index 497f9738641..101bf22cf16 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -649,7 +649,7 @@ void kgdb_arch_late(void) 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 39f9a1adaa7..d4b711c9a41 100644 --- a/drivers/serial/kgdboc.c +++ b/drivers/serial/kgdboc.c @@ -243,7 +243,7 @@ static struct kgdb_io kgdboc_io_ops = { #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 deda197ced6..aadff7cc2b8 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -139,6 +139,14 @@ int kdb_process_cpu(const struct task_struct *p) /* 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); diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h index 1921e6e4c0b..35d69ed1dfb 100644 --- a/kernel/debug/kdb/kdb_private.h +++ b/kernel/debug/kdb/kdb_private.h @@ -105,6 +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 **); @@ -216,14 +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); -#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 */ -- cgit v1.2.3-70-g09d2 From 495363d380b4f4745bd8677912688654afc44020 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 21 May 2010 08:46:00 -0500 Subject: kdb,debug_core: adjust master cpu switch logic against new debug_core locking The kdb shell needs to enforce switching back to the original CPU that took the exception before restoring normal kernel execution. Resuming from a different CPU than what took the original exception will cause problems with spin locks that are freed from the a different processor than had taken the lock. The special logic in dbg_cpu_switch() can go away entirely with because the state of what cpus want to be masters or slaves will remain unchanged between entry and exit of the debug_core exception context. Signed-off-by: Jason Wessel --- kernel/debug/debug_core.c | 16 ++-------------- kernel/debug/kdb/kdb_debugger.c | 3 +-- kernel/debug/kdb/kdb_main.c | 12 ++++++------ 3 files changed, 9 insertions(+), 22 deletions(-) (limited to 'kernel/debug/kdb') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 26dbdc37d21..fec596da9bd 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -460,19 +460,6 @@ static int kgdb_reenter_check(struct kgdb_state *ks) return 1; } -static void dbg_cpu_switch(int cpu, int next_cpu) -{ - /* 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; -} - static void dbg_touch_watchdogs(void) { touch_softlockup_watchdog_sync(); @@ -638,7 +625,8 @@ 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; diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c index bf6e8270e95..dd0b1b7dd02 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_main.c b/kernel/debug/kdb/kdb_main.c index 4226f32517d..d7bda21a106 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -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
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); -- cgit v1.2.3-70-g09d2 From 931ea24819f2bd40cca2dc214558bfcc3c91549e Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 29 Oct 2010 08:04:16 -0500 Subject: kdb: fix per_cpu command to remove supress mask Rusty pointed out that the per_cpu command uses up lots of space on the stack and the cpu supress mask is probably not needed. This patch removes the need for the supress mask as well as fixing up the following problems with the kdb per_cpu command: * The per_cpu command should allow an address as an argument * When you have more data than can be displayed on one screen allow the user to break out of the print loop. Reported-by: Rusty Russell Signed-off-by: Jason Wessel --- kernel/debug/kdb/kdb_main.c | 46 +++++++++++---------------------------------- 1 file changed, 11 insertions(+), 35 deletions(-) (limited to 'kernel/debug/kdb') diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index d7bda21a106..9755ac05e44 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -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; } -- cgit v1.2.3-70-g09d2 From 578bd4dfcda63d2ef15f025f1d5d55c0e56b9660 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 29 Oct 2010 13:14:41 -0500 Subject: kdb: Fix early debugging crash regression The kdb_current legally be equal to NULL in the early boot of the x86 arch. The problem pcan be observed by booting with the kernel arguments: earlyprintk=vga ekgdboc=kbd kgdbwait The kdb shell will oops on entry and recursively fault because it cannot get past the final stage of shell initialization. Signed-off-by: Jason Wessel --- kernel/debug/kdb/kdb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/debug/kdb') diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 9755ac05e44..37755d62192 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 -- cgit v1.2.3-70-g09d2