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-rw-r--r--include/linux/kdb.h1
-rw-r--r--kernel/debug/kdb/kdb_main.c30
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,