diff options
| -rw-r--r-- | include/linux/kdb.h | 1 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_main.c | 30 |
2 files changed, 30 insertions, 1 deletions
diff --git a/include/linux/kdb.h b/include/linux/kdb.h index f1fe36185c17..75ae2e2631fc 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -105,6 +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 diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index fae1fc3962f8..fe1ac56b62e9 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -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> @@ -42,6 +44,12 @@ #include <linux/slab.h> #include "kdb_private.h" +#undef MODULE_PARAM_PREFIX +#define MODULE_PARAM_PREFIX "kdb." + +static int kdb_cmd_enabled; +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 @@ -496,6 +505,15 @@ int kdbgetaddrarg(int argc, const char **argv, int *nextarg, 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: * * symbol | numeric-address [+/- numeric-offset] @@ -1028,6 +1046,10 @@ 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) @@ -1939,10 +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; @@ -2393,6 +2419,8 @@ 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, |