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authorLinus Torvalds <torvalds@linux-foundation.org>2013-03-02 08:31:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-02 08:31:39 -0800
commit3cfb07743a5bffecba83f0da26444e85c0a9bfbb (patch)
treec27f27a8d8f4bad9eed265cf0894d2ce8f058b1d
parente23b62256a361611cbd45cd1456638f1a5106b5c (diff)
parent36dfea42cc35509b481377980338cc3b89d79256 (diff)
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Merge tag 'for_linux-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb
Pull KGDB/KDB fixes and cleanups from Jason Wessel: "For a change we removed more code than we added. If people aren't using it we shouldn't be carrying it. :-) Cleanups: - Remove kdb ssb command - there is no in kernel disassembler to support it - Remove kdb ll command - Always caused a kernel oops and there were no bug reports so no one was using this command - Use kernel ARRAY_SIZE macro instead of array computations Fixes: - Stop oops in kdb if user executes kdb_defcmd with args - kdb help command truncated text - ppc64 support for kgdbts - Add missing kconfig option from original kdb port for dealing with catastrophic kernel crashes such that you can reboot automatically on continue from kdb" * tag 'for_linux-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb: kdb: Remove unhandled ssb command kdb: Prevent kernel oops with kdb_defcmd kdb: Remove the ll command kdb_main: fix help print kdb: Fix overlap in buffers with strcpy Fixed dead ifdef block by adding missing Kconfig option. kdb: Setup basic kdb state before invoking commands via kgdb kdb: use ARRAY_SIZE where possible kgdb/kgdbts: support ppc64 kdb: A fix for kdb command table expansion
-rw-r--r--drivers/misc/kgdbts.c2
-rw-r--r--kernel/debug/debug_core.h2
-rw-r--r--kernel/debug/gdbstub.c3
-rw-r--r--kernel/debug/kdb/kdb_bp.c20
-rw-r--r--kernel/debug/kdb/kdb_debugger.c25
-rw-r--r--kernel/debug/kdb/kdb_main.c135
-rw-r--r--kernel/debug/kdb/kdb_private.h4
-rw-r--r--lib/Kconfig.kgdb18
8 files changed, 82 insertions, 127 deletions
diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
index 3aa9a969b373..36f5d52775a9 100644
--- a/drivers/misc/kgdbts.c
+++ b/drivers/misc/kgdbts.c
@@ -103,6 +103,7 @@
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/module.h>
+#include <asm/sections.h>
#define v1printk(a...) do { \
if (verbose) \
@@ -222,6 +223,7 @@ static unsigned long lookup_addr(char *arg)
addr = (unsigned long)do_fork;
else if (!strcmp(arg, "hw_break_val"))
addr = (unsigned long)&hw_break_val;
+ addr = (unsigned long) dereference_function_descriptor((void *)addr);
return addr;
}
diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index 3494c28a7e7a..2235967e78b0 100644
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -72,6 +72,8 @@ extern int dbg_kdb_mode;
#ifdef CONFIG_KGDB_KDB
extern int kdb_stub(struct kgdb_state *ks);
extern int kdb_parse(const char *cmdstr);
+extern int kdb_common_init_state(struct kgdb_state *ks);
+extern int kdb_common_deinit_state(void);
#else /* ! CONFIG_KGDB_KDB */
static inline int kdb_stub(struct kgdb_state *ks)
{
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index 38573f35a5ad..19d9a578c753 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -783,7 +783,10 @@ static void gdb_cmd_query(struct kgdb_state *ks)
len = len / 2;
remcom_out_buffer[len++] = 0;
+ kdb_common_init_state(ks);
kdb_parse(remcom_out_buffer);
+ kdb_common_deinit_state();
+
strcpy(remcom_out_buffer, "OK");
}
break;
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index 8418c2f8ec5d..70a504601dc3 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -486,11 +486,9 @@ static int kdb_bc(int argc, const char **argv)
/*
* kdb_ss
*
- * Process the 'ss' (Single Step) and 'ssb' (Single Step to Branch)
- * commands.
+ * Process the 'ss' (Single Step) command.
*
* ss
- * ssb
*
* Parameters:
* argc Argument count
@@ -498,35 +496,23 @@ static int kdb_bc(int argc, const char **argv)
* Outputs:
* None.
* Returns:
- * KDB_CMD_SS[B] for success, a kdb error if failure.
+ * KDB_CMD_SS for success, a kdb error if failure.
* Locking:
* None.
* Remarks:
*
* Set the arch specific option to trigger a debug trap after the next
* instruction.
- *
- * For 'ssb', set the trace flag in the debug trap handler
- * after printing the current insn and return directly without
- * invoking the kdb command processor, until a branch instruction
- * is encountered.
*/
static int kdb_ss(int argc, const char **argv)
{
- int ssb = 0;
-
- ssb = (strcmp(argv[0], "ssb") == 0);
if (argc != 0)
return KDB_ARGCOUNT;
/*
* Set trace flag and go.
*/
KDB_STATE_SET(DOING_SS);
- if (ssb) {
- KDB_STATE_SET(DOING_SSB);
- return KDB_CMD_SSB;
- }
return KDB_CMD_SS;
}
@@ -561,8 +547,6 @@ void __init kdb_initbptab(void)
kdb_register_repeat("ss", kdb_ss, "",
"Single Step", 1, KDB_REPEAT_NO_ARGS);
- kdb_register_repeat("ssb", kdb_ss, "",
- "Single step to branch/call", 0, KDB_REPEAT_NO_ARGS);
/*
* Architecture dependent initialization.
*/
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index be7b33b73d30..328d18ef31e4 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -34,6 +34,22 @@ EXPORT_SYMBOL_GPL(kdb_poll_idx);
static struct kgdb_state *kdb_ks;
+int kdb_common_init_state(struct kgdb_state *ks)
+{
+ kdb_initial_cpu = atomic_read(&kgdb_active);
+ kdb_current_task = kgdb_info[ks->cpu].task;
+ kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
+ return 0;
+}
+
+int kdb_common_deinit_state(void)
+{
+ kdb_initial_cpu = -1;
+ kdb_current_task = NULL;
+ kdb_current_regs = NULL;
+ return 0;
+}
+
int kdb_stub(struct kgdb_state *ks)
{
int error = 0;
@@ -94,13 +110,10 @@ int kdb_stub(struct kgdb_state *ks)
}
/* Set initial kdb state variables */
KDB_STATE_CLEAR(KGDB_TRANS);
- kdb_initial_cpu = atomic_read(&kgdb_active);
- kdb_current_task = kgdb_info[ks->cpu].task;
- kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
+ kdb_common_init_state(ks);
/* Remove any breakpoints as needed by kdb and clear single step */
kdb_bp_remove();
KDB_STATE_CLEAR(DOING_SS);
- KDB_STATE_CLEAR(DOING_SSB);
KDB_STATE_SET(PAGER);
/* zero out any offline cpu data */
for_each_present_cpu(i) {
@@ -125,9 +138,7 @@ int kdb_stub(struct kgdb_state *ks)
* Upon exit from the kdb main loop setup break points and restart
* the system based on the requested continue state
*/
- kdb_initial_cpu = -1;
- kdb_current_task = NULL;
- kdb_current_regs = NULL;
+ kdb_common_deinit_state();
KDB_STATE_CLEAR(PAGER);
kdbnearsym_cleanup();
if (error == KDB_CMD_KGDB) {
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 8875254120b6..00eb8f7fbf41 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -124,7 +124,7 @@ static kdbmsg_t kdbmsgs[] = {
};
#undef KDBMSG
-static const int __nkdb_err = sizeof(kdbmsgs) / sizeof(kdbmsg_t);
+static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
/*
@@ -175,7 +175,7 @@ static char *__env[] = {
(char *)0,
};
-static const int __nenv = (sizeof(__env) / sizeof(char *));
+static const int __nenv = ARRAY_SIZE(__env);
struct task_struct *kdb_curr_task(int cpu)
{
@@ -681,34 +681,50 @@ static int kdb_defcmd(int argc, const char **argv)
}
if (argc != 3)
return KDB_ARGCOUNT;
- defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
- GFP_KDB);
- if (!defcmd_set) {
- kdb_printf("Could not allocate new defcmd_set entry for %s\n",
- argv[1]);
- defcmd_set = save_defcmd_set;
+ if (in_dbg_master()) {
+ kdb_printf("Command only available during kdb_init()\n");
return KDB_NOTIMP;
}
+ defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
+ GFP_KDB);
+ if (!defcmd_set)
+ goto fail_defcmd;
memcpy(defcmd_set, save_defcmd_set,
defcmd_set_count * sizeof(*defcmd_set));
- kfree(save_defcmd_set);
s = defcmd_set + defcmd_set_count;
memset(s, 0, sizeof(*s));
s->usable = 1;
s->name = kdb_strdup(argv[1], GFP_KDB);
+ if (!s->name)
+ goto fail_name;
s->usage = kdb_strdup(argv[2], GFP_KDB);
+ if (!s->usage)
+ goto fail_usage;
s->help = kdb_strdup(argv[3], GFP_KDB);
+ if (!s->help)
+ goto fail_help;
if (s->usage[0] == '"') {
- strcpy(s->usage, s->usage+1);
+ strcpy(s->usage, argv[2]+1);
s->usage[strlen(s->usage)-1] = '\0';
}
if (s->help[0] == '"') {
- strcpy(s->help, s->help+1);
+ strcpy(s->help, argv[3]+1);
s->help[strlen(s->help)-1] = '\0';
}
++defcmd_set_count;
defcmd_in_progress = 1;
+ kfree(save_defcmd_set);
return 0;
+fail_help:
+ kfree(s->usage);
+fail_usage:
+ kfree(s->name);
+fail_name:
+ kfree(defcmd_set);
+fail_defcmd:
+ kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]);
+ defcmd_set = save_defcmd_set;
+ return KDB_NOTIMP;
}
/*
@@ -1112,7 +1128,6 @@ void kdb_set_current_task(struct task_struct *p)
* KDB_CMD_GO User typed 'go'.
* KDB_CMD_CPU User switched to another cpu.
* KDB_CMD_SS Single step.
- * KDB_CMD_SSB Single step until branch.
*/
static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
kdb_dbtrap_t db_result)
@@ -1151,14 +1166,6 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
instruction_pointer(regs));
break;
- case KDB_DB_SSB:
- /*
- * In the midst of ssb command. Just return.
- */
- KDB_DEBUG_STATE("kdb_local 3", reason);
- return KDB_CMD_SSB; /* Continue with SSB command */
-
- break;
case KDB_DB_SS:
break;
case KDB_DB_SSBPT:
@@ -1281,7 +1288,6 @@ do_full_getstr:
if (diag == KDB_CMD_GO
|| diag == KDB_CMD_CPU
|| diag == KDB_CMD_SS
- || diag == KDB_CMD_SSB
|| diag == KDB_CMD_KGDB)
break;
@@ -1368,12 +1374,6 @@ int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
break;
}
- if (result == KDB_CMD_SSB) {
- KDB_STATE_SET(DOING_SS);
- KDB_STATE_SET(DOING_SSB);
- break;
- }
-
if (result == KDB_CMD_KGDB) {
if (!KDB_STATE(DOING_KGDB))
kdb_printf("Entering please attach debugger "
@@ -2350,69 +2350,6 @@ static int kdb_pid(int argc, const char **argv)
return 0;
}
-/*
- * kdb_ll - This function implements the 'll' command which follows a
- * linked list and executes an arbitrary command for each
- * element.
- */
-static int kdb_ll(int argc, const char **argv)
-{
- int diag = 0;
- unsigned long addr;
- long offset = 0;
- unsigned long va;
- unsigned long linkoffset;
- int nextarg;
- const char *command;
-
- if (argc != 3)
- return KDB_ARGCOUNT;
-
- nextarg = 1;
- diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
- if (diag)
- return diag;
-
- diag = kdbgetularg(argv[2], &linkoffset);
- if (diag)
- return diag;
-
- /*
- * Using the starting address as
- * the first element in the list, and assuming that
- * the list ends with a null pointer.
- */
-
- va = addr;
- command = kdb_strdup(argv[3], GFP_KDB);
- if (!command) {
- kdb_printf("%s: cannot duplicate command\n", __func__);
- return 0;
- }
- /* Recursive use of kdb_parse, do not use argv after this point */
- argv = NULL;
-
- while (va) {
- char buf[80];
-
- if (KDB_FLAG(CMD_INTERRUPT))
- goto out;
-
- sprintf(buf, "%s " kdb_machreg_fmt "\n", command, va);
- diag = kdb_parse(buf);
- if (diag)
- goto out;
-
- addr = va + linkoffset;
- if (kdb_getword(&va, addr, sizeof(va)))
- goto out;
- }
-
-out:
- kfree(command);
- return diag;
-}
-
static int kdb_kgdb(int argc, const char **argv)
{
return KDB_CMD_KGDB;
@@ -2430,11 +2367,15 @@ static int kdb_help(int argc, const char **argv)
kdb_printf("-----------------------------"
"-----------------------------\n");
for_each_kdbcmd(kt, i) {
- if (kt->cmd_name)
- kdb_printf("%-15.15s %-20.20s %s\n", kt->cmd_name,
- kt->cmd_usage, kt->cmd_help);
+ char *space = "";
if (KDB_FLAG(CMD_INTERRUPT))
return 0;
+ if (!kt->cmd_name)
+ continue;
+ if (strlen(kt->cmd_usage) > 20)
+ space = "\n ";
+ kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
+ kt->cmd_usage, space, kt->cmd_help);
}
return 0;
}
@@ -2739,7 +2680,7 @@ int kdb_register_repeat(char *cmd,
(kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
kfree(kdb_commands);
}
- memset(new + kdb_max_commands, 0,
+ memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
kdb_command_extend * sizeof(*new));
kdb_commands = new;
kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
@@ -2843,15 +2784,13 @@ static void __init kdb_inittab(void)
"Stack traceback", 1, KDB_REPEAT_NONE);
kdb_register_repeat("btp", kdb_bt, "<pid>",
"Display stack for process <pid>", 0, KDB_REPEAT_NONE);
- kdb_register_repeat("bta", kdb_bt, "[DRSTCZEUIMA]",
- "Display stack all processes", 0, KDB_REPEAT_NONE);
+ kdb_register_repeat("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
+ "Backtrace all processes matching state flag", 0, KDB_REPEAT_NONE);
kdb_register_repeat("btc", kdb_bt, "",
"Backtrace current process on each cpu", 0, KDB_REPEAT_NONE);
kdb_register_repeat("btt", kdb_bt, "<vaddr>",
"Backtrace process given its struct task address", 0,
KDB_REPEAT_NONE);
- kdb_register_repeat("ll", kdb_ll, "<first-element> <linkoffset> <cmd>",
- "Execute cmd for each element in linked list", 0, KDB_REPEAT_NONE);
kdb_register_repeat("env", kdb_env, "",
"Show environment variables", 0, KDB_REPEAT_NONE);
kdb_register_repeat("set", kdb_set, "",
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 392ec6a25844..7afd3c8c41d5 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -19,7 +19,6 @@
#define KDB_CMD_GO (-1001)
#define KDB_CMD_CPU (-1002)
#define KDB_CMD_SS (-1003)
-#define KDB_CMD_SSB (-1004)
#define KDB_CMD_KGDB (-1005)
/* Internal debug flags */
@@ -125,8 +124,6 @@ extern int kdb_state;
* kdb control */
#define KDB_STATE_HOLD_CPU 0x00000010 /* Hold this cpu inside kdb */
#define KDB_STATE_DOING_SS 0x00000020 /* Doing ss command */
-#define KDB_STATE_DOING_SSB 0x00000040 /* Doing ssb command,
- * DOING_SS is also set */
#define KDB_STATE_SSBPT 0x00000080 /* Install breakpoint
* after one ss, independent of
* DOING_SS */
@@ -191,7 +188,6 @@ extern void kdb_bp_remove(void);
typedef enum {
KDB_DB_BPT, /* Breakpoint */
KDB_DB_SS, /* Single-step trap */
- KDB_DB_SSB, /* Single step to branch */
KDB_DB_SSBPT, /* Single step over breakpoint */
KDB_DB_NOBPT /* Spurious breakpoint */
} kdb_dbtrap_t;
diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb
index dbb58ae1b8e0..140e87824173 100644
--- a/lib/Kconfig.kgdb
+++ b/lib/Kconfig.kgdb
@@ -80,4 +80,22 @@ config KDB_KEYBOARD
help
KDB can use a PS/2 type keyboard for an input device
+config KDB_CONTINUE_CATASTROPHIC
+ int "KDB: continue after catastrophic errors"
+ depends on KGDB_KDB
+ default "0"
+ help
+ This integer controls the behaviour of kdb when the kernel gets a
+ catastrophic error, i.e. for a panic or oops.
+ When KDB is active and a catastrophic error occurs, nothing extra
+ will happen until you type 'go'.
+ CONFIG_KDB_CONTINUE_CATASTROPHIC == 0 (default). The first time
+ you type 'go', you will be warned by kdb. The secend time you type
+ 'go', KDB tries to continue. No guarantees that the
+ kernel is still usable in this situation.
+ CONFIG_KDB_CONTINUE_CATASTROPHIC == 1. KDB tries to continue.
+ No guarantees that the kernel is still usable in this situation.
+ CONFIG_KDB_CONTINUE_CATASTROPHIC == 2. KDB forces a reboot.
+ If you are not sure, say 0.
+
endif # KGDB