Merge tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

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

1 files changed, 53 insertions, 9 deletions

diff --git a/include/linux/kdb.h b/include/linux/kdb.h
index 290db1269c4c..75ae2e2631fc 100644
--- a/include/linux/kdb.h
+++ b/include/linux/kdb.h
@@ -13,11 +13,54 @@
  * 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 {