Merge tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwess...
authorLinus Torvalds <torvalds@linux-foundation.org>
Sat, 10 Jan 2015 04:51:10 +0000 (20:51 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 10 Jan 2015 04:51:10 +0000 (20:51 -0800)
Pull kgdb/kdb fixes from Jason Wessel:
 "These have been around since 3.17 and in kgdb-next for the last 9
  weeks and some will go back to -stable.

  Summary of changes:

  Cleanups
   - kdb: Remove unused command flags, repeat flags and KDB_REPEAT_NONE

  Fixes
   - kgdb/kdb: Allow access on a single core, if a CPU round up is
     deemed impossible, which will allow inspection of the now "trashed"
     kernel
   - kdb: Add enable mask for the command groups
   - kdb: access controls to restrict sensitive commands"

* tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  kernel/debug/debug_core.c: Logging clean-up
  kgdb: timeout if secondary CPUs ignore the roundup
  kdb: Allow access to sensitive commands to be restricted by default
  kdb: Add enable mask for groups of commands
  kdb: Categorize kdb commands (similar to SysRq categorization)
  kdb: Remove KDB_REPEAT_NONE flag
  kdb: Use KDB_REPEAT_* values as flags
  kdb: Rename kdb_register_repeat() to kdb_register_flags()
  kdb: Rename kdb_repeat_t to kdb_cmdflags_t, cmd_repeat to cmd_flags
  kdb: Remove currently unused kdbtab_t->cmd_flags

include/linux/kdb.h
kernel/debug/debug_core.c
kernel/debug/kdb/kdb_bp.c
kernel/debug/kdb/kdb_debugger.c
kernel/debug/kdb/kdb_main.c
kernel/debug/kdb/kdb_private.h
kernel/trace/trace_kdb.c
lib/Kconfig.kgdb

index 290db12..75ae2e2 100644 (file)
  * Copyright (C) 2009 Jason Wessel <jason.wessel@windriver.com>
  */
 
+/* Shifted versions of the command enable bits are be used if the command
+ * has no arguments (see kdb_check_flags). This allows commands, such as
+ * go, to have different permissions depending upon whether it is called
+ * with an argument.
+ */
+#define KDB_ENABLE_NO_ARGS_SHIFT 10
+
 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;
+       KDB_ENABLE_ALL = (1 << 0), /* Enable everything */
+       KDB_ENABLE_MEM_READ = (1 << 1),
+       KDB_ENABLE_MEM_WRITE = (1 << 2),
+       KDB_ENABLE_REG_READ = (1 << 3),
+       KDB_ENABLE_REG_WRITE = (1 << 4),
+       KDB_ENABLE_INSPECT = (1 << 5),
+       KDB_ENABLE_FLOW_CTRL = (1 << 6),
+       KDB_ENABLE_SIGNAL = (1 << 7),
+       KDB_ENABLE_REBOOT = (1 << 8),
+       /* User exposed values stop here, all remaining flags are
+        * exclusively used to describe a commands behaviour.
+        */
+
+       KDB_ENABLE_ALWAYS_SAFE = (1 << 9),
+       KDB_ENABLE_MASK = (1 << KDB_ENABLE_NO_ARGS_SHIFT) - 1,
+
+       KDB_ENABLE_ALL_NO_ARGS = KDB_ENABLE_ALL << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_MEM_READ_NO_ARGS = KDB_ENABLE_MEM_READ
+                                     << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_MEM_WRITE_NO_ARGS = KDB_ENABLE_MEM_WRITE
+                                      << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_REG_READ_NO_ARGS = KDB_ENABLE_REG_READ
+                                     << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_REG_WRITE_NO_ARGS = KDB_ENABLE_REG_WRITE
+                                      << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_INSPECT_NO_ARGS = KDB_ENABLE_INSPECT
+                                    << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_FLOW_CTRL_NO_ARGS = KDB_ENABLE_FLOW_CTRL
+                                      << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_SIGNAL_NO_ARGS = KDB_ENABLE_SIGNAL
+                                   << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_REBOOT_NO_ARGS = KDB_ENABLE_REBOOT
+                                   << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_ALWAYS_SAFE_NO_ARGS = KDB_ENABLE_ALWAYS_SAFE
+                                        << KDB_ENABLE_NO_ARGS_SHIFT,
+       KDB_ENABLE_MASK_NO_ARGS = KDB_ENABLE_MASK << KDB_ENABLE_NO_ARGS_SHIFT,
+
+       KDB_REPEAT_NO_ARGS = 0x40000000, /* Repeat the command w/o arguments */
+       KDB_REPEAT_WITH_ARGS = 0x80000000, /* Repeat the command with args */
+} kdb_cmdflags_t;
 
 typedef int (*kdb_func_t)(int, const char **);
 
@@ -62,6 +105,7 @@ extern atomic_t kdb_event;
 #define KDB_BADLENGTH  (-19)
 #define KDB_NOBP       (-20)
 #define KDB_BADADDR    (-21)
+#define KDB_NOPERM     (-22)
 
 /*
  * kdb_diemsg
@@ -146,17 +190,17 @@ static inline const char *kdb_walk_kallsyms(loff_t *pos)
 
 /* 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_register_flags(char *, kdb_func_t, char *, char *,
+                             short, kdb_cmdflags_t);
 extern int kdb_unregister(char *);
 #else /* ! CONFIG_KGDB_KDB */
 static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
 static inline void kdb_init(int level) {}
 static inline int kdb_register(char *cmd, kdb_func_t func, char *usage,
                               char *help, short minlen) { return 0; }
-static inline int kdb_register_repeat(char *cmd, kdb_func_t func, char *usage,
-                                     char *help, short minlen,
-                                     kdb_repeat_t repeat) { return 0; }
+static inline int kdb_register_flags(char *cmd, kdb_func_t func, char *usage,
+                                    char *help, short minlen,
+                                    kdb_cmdflags_t flags) { return 0; }
 static inline int kdb_unregister(char *cmd) { return 0; }
 #endif /* CONFIG_KGDB_KDB */
 enum {
index 1adf62b..07ce18c 100644 (file)
@@ -27,6 +27,9 @@
  * version 2. This program is licensed "as is" without any warranty of any
  * kind, whether express or implied.
  */
+
+#define pr_fmt(fmt) "KGDB: " fmt
+
 #include <linux/pid_namespace.h>
 #include <linux/clocksource.h>
 #include <linux/serial_core.h>
@@ -196,8 +199,8 @@ int __weak kgdb_validate_break_address(unsigned long addr)
                return err;
        err = kgdb_arch_remove_breakpoint(&tmp);
        if (err)
-               printk(KERN_ERR "KGDB: Critical breakpoint error, kernel "
-                  "memory destroyed at: %lx", addr);
+               pr_err("Critical breakpoint error, kernel memory destroyed at: %lx\n",
+                      addr);
        return err;
 }
 
@@ -256,8 +259,8 @@ int dbg_activate_sw_breakpoints(void)
                error = kgdb_arch_set_breakpoint(&kgdb_break[i]);
                if (error) {
                        ret = error;
-                       printk(KERN_INFO "KGDB: BP install failed: %lx",
-                              kgdb_break[i].bpt_addr);
+                       pr_info("BP install failed: %lx\n",
+                               kgdb_break[i].bpt_addr);
                        continue;
                }
 
@@ -319,8 +322,8 @@ int dbg_deactivate_sw_breakpoints(void)
                        continue;
                error = kgdb_arch_remove_breakpoint(&kgdb_break[i]);
                if (error) {
-                       printk(KERN_INFO "KGDB: BP remove failed: %lx\n",
-                              kgdb_break[i].bpt_addr);
+                       pr_info("BP remove failed: %lx\n",
+                               kgdb_break[i].bpt_addr);
                        ret = error;
                }
 
@@ -367,7 +370,7 @@ int dbg_remove_all_break(void)
                        goto setundefined;
                error = kgdb_arch_remove_breakpoint(&kgdb_break[i]);
                if (error)
-                       printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n",
+                       pr_err("breakpoint remove failed: %lx\n",
                               kgdb_break[i].bpt_addr);
 setundefined:
                kgdb_break[i].state = BP_UNDEFINED;
@@ -400,9 +403,9 @@ static int kgdb_io_ready(int print_wait)
        if (print_wait) {
 #ifdef CONFIG_KGDB_KDB
                if (!dbg_kdb_mode)
-                       printk(KERN_CRIT "KGDB: waiting... or $3#33 for KDB\n");
+                       pr_crit("waiting... or $3#33 for KDB\n");
 #else
-               printk(KERN_CRIT "KGDB: Waiting for remote debugger\n");
+               pr_crit("Waiting for remote debugger\n");
 #endif
        }
        return 1;
@@ -430,8 +433,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
                exception_level = 0;
                kgdb_skipexception(ks->ex_vector, ks->linux_regs);
                dbg_activate_sw_breakpoints();
-               printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n",
-                       addr);
+               pr_crit("re-enter error: breakpoint removed %lx\n", addr);
                WARN_ON_ONCE(1);
 
                return 1;
@@ -444,7 +446,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
                panic("Recursive entry to debugger");
        }
 
-       printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n");
+       pr_crit("re-enter exception: ALL breakpoints killed\n");
 #ifdef CONFIG_KGDB_KDB
        /* Allow kdb to debug itself one level */
        return 0;
@@ -471,6 +473,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
        int cpu;
        int trace_on = 0;
        int online_cpus = num_online_cpus();
+       u64 time_left;
 
        kgdb_info[ks->cpu].enter_kgdb++;
        kgdb_info[ks->cpu].exception_state |= exception_state;
@@ -595,9 +598,13 @@ return_normal:
        /*
         * Wait for the other CPUs to be notified and be waiting for us:
         */
-       while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) +
-                               atomic_read(&slaves_in_kgdb)) != online_cpus)
+       time_left = loops_per_jiffy * HZ;
+       while (kgdb_do_roundup && --time_left &&
+              (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) !=
+                  online_cpus)
                cpu_relax();
+       if (!time_left)
+               pr_crit("KGDB: Timed out waiting for secondary CPUs.\n");
 
        /*
         * At this point the primary processor is completely
@@ -795,15 +802,15 @@ static struct console kgdbcons = {
 static void sysrq_handle_dbg(int key)
 {
        if (!dbg_io_ops) {
-               printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
+               pr_crit("ERROR: No KGDB I/O module available\n");
                return;
        }
        if (!kgdb_connected) {
 #ifdef CONFIG_KGDB_KDB
                if (!dbg_kdb_mode)
-                       printk(KERN_CRIT "KGDB or $3#33 for KDB\n");
+                       pr_crit("KGDB or $3#33 for KDB\n");
 #else
-               printk(KERN_CRIT "Entering KGDB\n");
+               pr_crit("Entering KGDB\n");
 #endif
        }
 
@@ -945,7 +952,7 @@ static void kgdb_initial_breakpoint(void)
 {
        kgdb_break_asap = 0;
 
-       printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n");
+       pr_crit("Waiting for connection from remote gdb...\n");
        kgdb_breakpoint();
 }
 
@@ -964,8 +971,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
        if (dbg_io_ops) {
                spin_unlock(&kgdb_registration_lock);
 
-               printk(KERN_ERR "kgdb: Another I/O driver is already "
-                               "registered with KGDB.\n");
+               pr_err("Another I/O driver is already registered with KGDB\n");
                return -EBUSY;
        }
 
@@ -981,8 +987,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops)
 
        spin_unlock(&kgdb_registration_lock);
 
-       printk(KERN_INFO "kgdb: Registered I/O driver %s.\n",
-              new_dbg_io_ops->name);
+       pr_info("Registered I/O driver %s\n", new_dbg_io_ops->name);
 
        /* Arm KGDB now. */
        kgdb_register_callbacks();
@@ -1017,8 +1022,7 @@ void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops)
 
        spin_unlock(&kgdb_registration_lock);
 
-       printk(KERN_INFO
-               "kgdb: Unregistered I/O driver %s, debugger disabled.\n",
+       pr_info("Unregistered I/O driver %s, debugger disabled\n",
                old_dbg_io_ops->name);
 }
 EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
index b20d544..e1dbf4a 100644 (file)
@@ -531,22 +531,29 @@ void __init kdb_initbptab(void)
        for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++)
                bp->bp_free = 1;
 
-       kdb_register_repeat("bp", kdb_bp, "[<vaddr>]",
-               "Set/Display breakpoints", 0, KDB_REPEAT_NO_ARGS);
-       kdb_register_repeat("bl", kdb_bp, "[<vaddr>]",
-               "Display breakpoints", 0, KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("bp", kdb_bp, "[<vaddr>]",
+               "Set/Display breakpoints", 0,
+               KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("bl", kdb_bp, "[<vaddr>]",
+               "Display breakpoints", 0,
+               KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
        if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)
-               kdb_register_repeat("bph", kdb_bp, "[<vaddr>]",
-               "[datar [length]|dataw [length]]   Set hw brk", 0, KDB_REPEAT_NO_ARGS);
-       kdb_register_repeat("bc", kdb_bc, "<bpnum>",
-               "Clear Breakpoint", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("be", kdb_bc, "<bpnum>",
-               "Enable Breakpoint", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("bd", kdb_bc, "<bpnum>",
-               "Disable Breakpoint", 0, KDB_REPEAT_NONE);
-
-       kdb_register_repeat("ss", kdb_ss, "",
-               "Single Step", 1, KDB_REPEAT_NO_ARGS);
+               kdb_register_flags("bph", kdb_bp, "[<vaddr>]",
+               "[datar [length]|dataw [length]]   Set hw brk", 0,
+               KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("bc", kdb_bc, "<bpnum>",
+               "Clear Breakpoint", 0,
+               KDB_ENABLE_FLOW_CTRL);
+       kdb_register_flags("be", kdb_bc, "<bpnum>",
+               "Enable Breakpoint", 0,
+               KDB_ENABLE_FLOW_CTRL);
+       kdb_register_flags("bd", kdb_bc, "<bpnum>",
+               "Disable Breakpoint", 0,
+               KDB_ENABLE_FLOW_CTRL);
+
+       kdb_register_flags("ss", kdb_ss, "",
+               "Single Step", 1,
+               KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
        /*
         * Architecture dependent initialization.
         */
index 8859ca3..15e1a7a 100644 (file)
@@ -129,6 +129,10 @@ int kdb_stub(struct kgdb_state *ks)
                ks->pass_exception = 1;
                KDB_FLAG_SET(CATASTROPHIC);
        }
+       /* set CATASTROPHIC if the system contains unresponsive processors */
+       for_each_online_cpu(i)
+               if (!kgdb_info[i].enter_kgdb)
+                       KDB_FLAG_SET(CATASTROPHIC);
        if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
                KDB_STATE_CLEAR(SSBPT);
                KDB_STATE_CLEAR(DOING_SS);
index 379650b..f191bdd 100644 (file)
@@ -12,6 +12,7 @@
  */
 
 #include <linux/ctype.h>
+#include <linux/types.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/kmsg_dump.h>
@@ -23,6 +24,7 @@
 #include <linux/vmalloc.h>
 #include <linux/atomic.h>
 #include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/mm.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
 #include <linux/slab.h>
 #include "kdb_private.h"
 
+#undef MODULE_PARAM_PREFIX
+#define        MODULE_PARAM_PREFIX "kdb."
+
+static int kdb_cmd_enabled = CONFIG_KDB_DEFAULT_ENABLE;
+module_param_named(cmd_enable, kdb_cmd_enabled, int, 0600);
+
 #define GREP_LEN 256
 char kdb_grep_string[GREP_LEN];
 int kdb_grepping_flag;
@@ -121,6 +129,7 @@ static kdbmsg_t kdbmsgs[] = {
        KDBMSG(BADLENGTH, "Invalid length field"),
        KDBMSG(NOBP, "No Breakpoint exists"),
        KDBMSG(BADADDR, "Invalid address"),
+       KDBMSG(NOPERM, "Permission denied"),
 };
 #undef KDBMSG
 
@@ -187,6 +196,26 @@ struct task_struct *kdb_curr_task(int cpu)
        return p;
 }
 
+/*
+ * Check whether the flags of the current command and the permissions
+ * of the kdb console has allow a command to be run.
+ */
+static inline bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
+                                  bool no_args)
+{
+       /* permissions comes from userspace so needs massaging slightly */
+       permissions &= KDB_ENABLE_MASK;
+       permissions |= KDB_ENABLE_ALWAYS_SAFE;
+
+       /* some commands change group when launched with no arguments */
+       if (no_args)
+               permissions |= permissions << KDB_ENABLE_NO_ARGS_SHIFT;
+
+       flags |= KDB_ENABLE_ALL;
+
+       return permissions & flags;
+}
+
 /*
  * kdbgetenv - This function will return the character string value of
  *     an environment variable.
@@ -475,6 +504,15 @@ int kdbgetaddrarg(int argc, const char **argv, int *nextarg,
        char *cp;
        kdb_symtab_t symtab;
 
+       /*
+        * If the enable flags prohibit both arbitrary memory access
+        * and flow control then there are no reasonable grounds to
+        * provide symbol lookup.
+        */
+       if (!kdb_check_flags(KDB_ENABLE_MEM_READ | KDB_ENABLE_FLOW_CTRL,
+                            kdb_cmd_enabled, false))
+               return KDB_NOPERM;
+
        /*
         * Process arguments which follow the following syntax:
         *
@@ -641,8 +679,13 @@ static int kdb_defcmd2(const char *cmdstr, const char *argv0)
                if (!s->count)
                        s->usable = 0;
                if (s->usable)
-                       kdb_register(s->name, kdb_exec_defcmd,
-                                    s->usage, s->help, 0);
+                       /* macros are always safe because when executed each
+                        * internal command re-enters kdb_parse() and is
+                        * safety checked individually.
+                        */
+                       kdb_register_flags(s->name, kdb_exec_defcmd, s->usage,
+                                          s->help, 0,
+                                          KDB_ENABLE_ALWAYS_SAFE);
                return 0;
        }
        if (!s->usable)
@@ -1003,25 +1046,22 @@ int kdb_parse(const char *cmdstr)
 
        if (i < kdb_max_commands) {
                int result;
+
+               if (!kdb_check_flags(tp->cmd_flags, kdb_cmd_enabled, argc <= 1))
+                       return KDB_NOPERM;
+
                KDB_STATE_SET(CMD);
                result = (*tp->cmd_func)(argc-1, (const char **)argv);
                if (result && ignore_errors && result > KDB_CMD_GO)
                        result = 0;
                KDB_STATE_CLEAR(CMD);
-               switch (tp->cmd_repeat) {
-               case KDB_REPEAT_NONE:
-                       argc = 0;
-                       if (argv[0])
-                               *(argv[0]) = '\0';
-                       break;
-               case KDB_REPEAT_NO_ARGS:
-                       argc = 1;
-                       if (argv[1])
-                               *(argv[1]) = '\0';
-                       break;
-               case KDB_REPEAT_WITH_ARGS:
-                       break;
-               }
+
+               if (tp->cmd_flags & KDB_REPEAT_WITH_ARGS)
+                       return result;
+
+               argc = tp->cmd_flags & KDB_REPEAT_NO_ARGS ? 1 : 0;
+               if (argv[argc])
+                       *(argv[argc]) = '\0';
                return result;
        }
 
@@ -1921,10 +1961,14 @@ static int kdb_rm(int argc, const char **argv)
  */
 static int kdb_sr(int argc, const char **argv)
 {
+       bool check_mask =
+           !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
+
        if (argc != 1)
                return KDB_ARGCOUNT;
+
        kdb_trap_printk++;
-       __handle_sysrq(*argv[1], false);
+       __handle_sysrq(*argv[1], check_mask);
        kdb_trap_printk--;
 
        return 0;
@@ -2157,6 +2201,8 @@ static void kdb_cpu_status(void)
        for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
                if (!cpu_online(i)) {
                        state = 'F';    /* cpu is offline */
+               } else if (!kgdb_info[i].enter_kgdb) {
+                       state = 'D';    /* cpu is online but unresponsive */
                } else {
                        state = ' ';    /* cpu is responding to kdb */
                        if (kdb_task_state_char(KDB_TSK(i)) == 'I')
@@ -2210,7 +2256,7 @@ static int kdb_cpu(int argc, const char **argv)
        /*
         * Validate cpunum
         */
-       if ((cpunum > NR_CPUS) || !cpu_online(cpunum))
+       if ((cpunum > NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
                return KDB_BADCPUNUM;
 
        dbg_switch_cpu = cpunum;
@@ -2375,6 +2421,8 @@ static int kdb_help(int argc, const char **argv)
                        return 0;
                if (!kt->cmd_name)
                        continue;
+               if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true))
+                       continue;
                if (strlen(kt->cmd_usage) > 20)
                        space = "\n                                    ";
                kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
@@ -2629,7 +2677,7 @@ static int kdb_grep_help(int argc, const char **argv)
 }
 
 /*
- * kdb_register_repeat - This function is used to register a kernel
+ * kdb_register_flags - This function is used to register a kernel
  *     debugger command.
  * Inputs:
  *     cmd     Command name
@@ -2641,12 +2689,12 @@ static int kdb_grep_help(int argc, const char **argv)
  *     zero for success, one if a duplicate command.
  */
 #define kdb_command_extend 50  /* arbitrary */
-int kdb_register_repeat(char *cmd,
-                       kdb_func_t func,
-                       char *usage,
-                       char *help,
-                       short minlen,
-                       kdb_repeat_t repeat)
+int kdb_register_flags(char *cmd,
+                      kdb_func_t func,
+                      char *usage,
+                      char *help,
+                      short minlen,
+                      kdb_cmdflags_t flags)
 {
        int i;
        kdbtab_t *kp;
@@ -2694,19 +2742,18 @@ int kdb_register_repeat(char *cmd,
        kp->cmd_func   = func;
        kp->cmd_usage  = usage;
        kp->cmd_help   = help;
-       kp->cmd_flags  = 0;
        kp->cmd_minlen = minlen;
-       kp->cmd_repeat = repeat;
+       kp->cmd_flags  = flags;
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(kdb_register_repeat);
+EXPORT_SYMBOL_GPL(kdb_register_flags);
 
 
 /*
  * kdb_register - Compatibility register function for commands that do
  *     not need to specify a repeat state.  Equivalent to
- *     kdb_register_repeat with KDB_REPEAT_NONE.
+ *     kdb_register_flags with flags set to 0.
  * Inputs:
  *     cmd     Command name
  *     func    Function to execute the command
@@ -2721,8 +2768,7 @@ int kdb_register(char *cmd,
             char *help,
             short minlen)
 {
-       return kdb_register_repeat(cmd, func, usage, help, minlen,
-                                  KDB_REPEAT_NONE);
+       return kdb_register_flags(cmd, func, usage, help, minlen, 0);
 }
 EXPORT_SYMBOL_GPL(kdb_register);
 
@@ -2764,80 +2810,109 @@ static void __init kdb_inittab(void)
        for_each_kdbcmd(kp, i)
                kp->cmd_name = NULL;
 
-       kdb_register_repeat("md", kdb_md, "<vaddr>",
+       kdb_register_flags("md", kdb_md, "<vaddr>",
          "Display Memory Contents, also mdWcN, e.g. md8c1", 1,
-                           KDB_REPEAT_NO_ARGS);
-       kdb_register_repeat("mdr", kdb_md, "<vaddr> <bytes>",
-         "Display Raw Memory", 0, KDB_REPEAT_NO_ARGS);
-       kdb_register_repeat("mdp", kdb_md, "<paddr> <bytes>",
-         "Display Physical Memory", 0, KDB_REPEAT_NO_ARGS);
-       kdb_register_repeat("mds", kdb_md, "<vaddr>",
-         "Display Memory Symbolically", 0, KDB_REPEAT_NO_ARGS);
-       kdb_register_repeat("mm", kdb_mm, "<vaddr> <contents>",
-         "Modify Memory Contents", 0, KDB_REPEAT_NO_ARGS);
-       kdb_register_repeat("go", kdb_go, "[<vaddr>]",
-         "Continue Execution", 1, KDB_REPEAT_NONE);
-       kdb_register_repeat("rd", kdb_rd, "",
-         "Display Registers", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("rm", kdb_rm, "<reg> <contents>",
-         "Modify Registers", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("ef", kdb_ef, "<vaddr>",
-         "Display exception frame", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("bt", kdb_bt, "[<vaddr>]",
-         "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, "[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>",
+         KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
+         "Display Raw Memory", 0,
+         KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
+         "Display Physical Memory", 0,
+         KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("mds", kdb_md, "<vaddr>",
+         "Display Memory Symbolically", 0,
+         KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
+         "Modify Memory Contents", 0,
+         KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("go", kdb_go, "[<vaddr>]",
+         "Continue Execution", 1,
+         KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
+       kdb_register_flags("rd", kdb_rd, "",
+         "Display Registers", 0,
+         KDB_ENABLE_REG_READ);
+       kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
+         "Modify Registers", 0,
+         KDB_ENABLE_REG_WRITE);
+       kdb_register_flags("ef", kdb_ef, "<vaddr>",
+         "Display exception frame", 0,
+         KDB_ENABLE_MEM_READ);
+       kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
+         "Stack traceback", 1,
+         KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
+       kdb_register_flags("btp", kdb_bt, "<pid>",
+         "Display stack for process <pid>", 0,
+         KDB_ENABLE_INSPECT);
+       kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
+         "Backtrace all processes matching state flag", 0,
+         KDB_ENABLE_INSPECT);
+       kdb_register_flags("btc", kdb_bt, "",
+         "Backtrace current process on each cpu", 0,
+         KDB_ENABLE_INSPECT);
+       kdb_register_flags("btt", kdb_bt, "<vaddr>",
          "Backtrace process given its struct task address", 0,
-                           KDB_REPEAT_NONE);
-       kdb_register_repeat("env", kdb_env, "",
-         "Show environment variables", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("set", kdb_set, "",
-         "Set environment variables", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("help", kdb_help, "",
-         "Display Help Message", 1, KDB_REPEAT_NONE);
-       kdb_register_repeat("?", kdb_help, "",
-         "Display Help Message", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("cpu", kdb_cpu, "<cpunum>",
-         "Switch to new cpu", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("kgdb", kdb_kgdb, "",
-         "Enter kgdb mode", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("ps", kdb_ps, "[<flags>|A]",
-         "Display active task list", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("pid", kdb_pid, "<pidnum>",
-         "Switch to another task", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("reboot", kdb_reboot, "",
-         "Reboot the machine immediately", 0, KDB_REPEAT_NONE);
+         KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
+       kdb_register_flags("env", kdb_env, "",
+         "Show environment variables", 0,
+         KDB_ENABLE_ALWAYS_SAFE);
+       kdb_register_flags("set", kdb_set, "",
+         "Set environment variables", 0,
+         KDB_ENABLE_ALWAYS_SAFE);
+       kdb_register_flags("help", kdb_help, "",
+         "Display Help Message", 1,
+         KDB_ENABLE_ALWAYS_SAFE);
+       kdb_register_flags("?", kdb_help, "",
+         "Display Help Message", 0,
+         KDB_ENABLE_ALWAYS_SAFE);
+       kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
+         "Switch to new cpu", 0,
+         KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
+       kdb_register_flags("kgdb", kdb_kgdb, "",
+         "Enter kgdb mode", 0, 0);
+       kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
+         "Display active task list", 0,
+         KDB_ENABLE_INSPECT);
+       kdb_register_flags("pid", kdb_pid, "<pidnum>",
+         "Switch to another task", 0,
+         KDB_ENABLE_INSPECT);
+       kdb_register_flags("reboot", kdb_reboot, "",
+         "Reboot the machine immediately", 0,
+         KDB_ENABLE_REBOOT);
 #if defined(CONFIG_MODULES)
-       kdb_register_repeat("lsmod", kdb_lsmod, "",
-         "List loaded kernel modules", 0, KDB_REPEAT_NONE);
+       kdb_register_flags("lsmod", kdb_lsmod, "",
+         "List loaded kernel modules", 0,
+         KDB_ENABLE_INSPECT);
 #endif
 #if defined(CONFIG_MAGIC_SYSRQ)
-       kdb_register_repeat("sr", kdb_sr, "<key>",
-         "Magic SysRq key", 0, KDB_REPEAT_NONE);
+       kdb_register_flags("sr", kdb_sr, "<key>",
+         "Magic SysRq key", 0,
+         KDB_ENABLE_ALWAYS_SAFE);
 #endif
 #if defined(CONFIG_PRINTK)
-       kdb_register_repeat("dmesg", kdb_dmesg, "[lines]",
-         "Display syslog buffer", 0, KDB_REPEAT_NONE);
+       kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
+         "Display syslog buffer", 0,
+         KDB_ENABLE_ALWAYS_SAFE);
 #endif
        if (arch_kgdb_ops.enable_nmi) {
-               kdb_register_repeat("disable_nmi", kdb_disable_nmi, "",
-                 "Disable NMI entry to KDB", 0, KDB_REPEAT_NONE);
-       }
-       kdb_register_repeat("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
-         "Define a set of commands, down to endefcmd", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("kill", kdb_kill, "<-signal> <pid>",
-         "Send a signal to a process", 0, KDB_REPEAT_NONE);
-       kdb_register_repeat("summary", kdb_summary, "",
-         "Summarize the system", 4, KDB_REPEAT_NONE);
-       kdb_register_repeat("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
-         "Display per_cpu variables", 3, KDB_REPEAT_NONE);
-       kdb_register_repeat("grephelp", kdb_grep_help, "",
-         "Display help on | grep", 0, KDB_REPEAT_NONE);
+               kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
+                 "Disable NMI entry to KDB", 0,
+                 KDB_ENABLE_ALWAYS_SAFE);
+       }
+       kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
+         "Define a set of commands, down to endefcmd", 0,
+         KDB_ENABLE_ALWAYS_SAFE);
+       kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
+         "Send a signal to a process", 0,
+         KDB_ENABLE_SIGNAL);
+       kdb_register_flags("summary", kdb_summary, "",
+         "Summarize the system", 4,
+         KDB_ENABLE_ALWAYS_SAFE);
+       kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
+         "Display per_cpu variables", 3,
+         KDB_ENABLE_MEM_READ);
+       kdb_register_flags("grephelp", kdb_grep_help, "",
+         "Display help on | grep", 0,
+         KDB_ENABLE_ALWAYS_SAFE);
 }
 
 /* Execute any commands defined in kdb_cmds.  */
index 7afd3c8..eaacd16 100644 (file)
@@ -172,10 +172,9 @@ typedef struct _kdbtab {
        kdb_func_t cmd_func;            /* Function to execute command */
        char    *cmd_usage;             /* Usage String for this command */
        char    *cmd_help;              /* Help message for this command */
-       short    cmd_flags;             /* Parsing flags */
        short    cmd_minlen;            /* Minimum legal # command
                                         * chars required */
-       kdb_repeat_t cmd_repeat;        /* Does command auto repeat on enter? */
+       kdb_cmdflags_t cmd_flags;       /* Command behaviour flags */
 } kdbtab_t;
 
 extern int kdb_bt(int, const char **); /* KDB display back trace */
index b0b1c44..3ccf5c2 100644 (file)
@@ -132,8 +132,8 @@ static int kdb_ftdump(int argc, const char **argv)
 
 static __init int kdb_ftrace_register(void)
 {
-       kdb_register_repeat("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
-                           "Dump ftrace log", 0, KDB_REPEAT_NONE);
+       kdb_register_flags("ftdump", kdb_ftdump, "[skip_#lines] [cpu]",
+                           "Dump ftrace log", 0, KDB_ENABLE_ALWAYS_SAFE);
        return 0;
 }
 
index 358eb81..c635a10 100644 (file)
@@ -73,6 +73,31 @@ config KGDB_KDB
        help
          KDB frontend for kernel
 
+config KDB_DEFAULT_ENABLE
+       hex "KDB: Select kdb command functions to be enabled by default"
+       depends on KGDB_KDB
+       default 0x1
+       help
+         Specifiers which kdb commands are enabled by default. This may
+         be set to 1 or 0 to enable all commands or disable almost all
+         commands.
+
+         Alternatively the following bitmask applies:
+
+           0x0002 - allow arbitrary reads from memory and symbol lookup
+           0x0004 - allow arbitrary writes to memory
+           0x0008 - allow current register state to be inspected
+           0x0010 - allow current register state to be modified
+           0x0020 - allow passive inspection (backtrace, process list, lsmod)
+           0x0040 - allow flow control management (breakpoint, single step)
+           0x0080 - enable signalling of processes
+           0x0100 - allow machine to be rebooted
+
+         The config option merely sets the default at boot time. Both
+         issuing 'echo X > /sys/module/kdb/parameters/cmd_enable' or
+          setting with kdb.cmd_enable=X kernel command line option will
+         override the default settings.
+
 config KDB_KEYBOARD
        bool "KGDB_KDB: keyboard as input device"
        depends on VT && KGDB_KDB