Merge branch 'for-5.8' into for-linus

6 files changed, 19 insertions, 25 deletions

diff --git a/kernel/debug/kdb/.gitignore b/kernel/debug/kdb/.gitignore
index 396d12eda9e8..df259542a236 100644
--- a/kernel/debug/kdb/.gitignore
+++ b/kernel/debug/kdb/.gitignore
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
 gen-kdb_cmds.c
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index 62c301ad0773..d7ebb2c79cb8 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -412,7 +412,6 @@ static int kdb_bc(int argc, const char **argv)
 		 * assume that the breakpoint number is desired.
 		 */
 		if (addr < KDB_MAXBPT) {
-			bp = &kdb_breakpoints[addr];
 			lowbp = highbp = addr;
 			highbp++;
 		} else {
diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c
index 4af48ac53625..3de0cc780c16 100644
--- a/kernel/debug/kdb/kdb_bt.c
+++ b/kernel/debug/kdb/kdb_bt.c
@@ -119,7 +119,6 @@ kdb_bt_cpu(unsigned long cpu)
 		return;
 	}
 
-	kdb_set_current_task(kdb_tsk);
 	kdb_bt1(kdb_tsk, ~0UL, false);
 }
 
@@ -166,10 +165,8 @@ kdb_bt(int argc, const char **argv)
 		if (diag)
 			return diag;
 		p = find_task_by_pid_ns(pid, &init_pid_ns);
-		if (p) {
-			kdb_set_current_task(p);
+		if (p)
 			return kdb_bt1(p, ~0UL, false);
-		}
 		kdb_printf("No process with pid == %ld found\n", pid);
 		return 0;
 	} else if (strcmp(argv[0], "btt") == 0) {
@@ -178,11 +175,9 @@ kdb_bt(int argc, const char **argv)
 		diag = kdbgetularg((char *)argv[1], &addr);
 		if (diag)
 			return diag;
-		kdb_set_current_task((struct task_struct *)addr);
 		return kdb_bt1((struct task_struct *)addr, ~0UL, false);
 	} else if (strcmp(argv[0], "btc") == 0) {
 		unsigned long cpu = ~0;
-		struct task_struct *save_current_task = kdb_current_task;
 		if (argc > 1)
 			return KDB_ARGCOUNT;
 		if (argc == 1) {
@@ -204,7 +199,6 @@ kdb_bt(int argc, const char **argv)
 				kdb_bt_cpu(cpu);
 				touch_nmi_watchdog();
 			}
-			kdb_set_current_task(save_current_task);
 		}
 		return 0;
 	} else {
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 8bcdded5d61f..924bc9298a42 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -553,7 +553,7 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
 	int this_cpu, old_cpu;
 	char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
 	char *moreprompt = "more> ";
-	struct console *c = console_drivers;
+	struct console *c;
 	unsigned long uninitialized_var(flags);
 
 	/* Serialize kdb_printf if multiple cpus try to write at once.
@@ -698,10 +698,9 @@ kdb_printit:
 				cp2++;
 			}
 		}
-		while (c) {
+		for_each_console(c) {
 			c->write(c, cp, retlen - (cp - kdb_buffer));
 			touch_nmi_watchdog();
-			c = c->next;
 		}
 	}
 	if (logging) {
@@ -752,7 +751,6 @@ kdb_printit:
 			moreprompt = "more> ";
 
 		kdb_input_flush();
-		c = console_drivers;
 
 		if (dbg_io_ops && !dbg_io_ops->is_console) {
 			len = strlen(moreprompt);
@@ -762,10 +760,9 @@ kdb_printit:
 				cp++;
 			}
 		}
-		while (c) {
+		for_each_console(c) {
 			c->write(c, moreprompt, strlen(moreprompt));
 			touch_nmi_watchdog();
-			c = c->next;
 		}
 
 		if (logging)
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 4567fe998c30..515379cbf209 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -73,7 +73,6 @@ int kdb_nextline = 1;
 int kdb_state;			/* General KDB state */
 
 struct task_struct *kdb_current_task;
-EXPORT_SYMBOL(kdb_current_task);
 struct pt_regs *kdb_current_regs;
 
 const char *kdb_diemsg;
@@ -400,6 +399,13 @@ int kdb_set(int argc, const char **argv)
 		return KDB_ARGCOUNT;
 
 	/*
+	 * Censor sensitive variables
+	 */
+	if (strcmp(argv[1], "PROMPT") == 0 &&
+	    !kdb_check_flags(KDB_ENABLE_MEM_READ, kdb_cmd_enabled, false))
+		return KDB_NOPERM;
+
+	/*
 	 * Check for internal variables
 	 */
 	if (strcmp(argv[1], "KDBDEBUG") == 0) {
@@ -1103,12 +1109,12 @@ static int handle_ctrl_cmd(char *cmd)
 	case CTRL_P:
 		if (cmdptr != cmd_tail)
 			cmdptr = (cmdptr-1) % KDB_CMD_HISTORY_COUNT;
-		strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
+		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
 		return 1;
 	case CTRL_N:
 		if (cmdptr != cmd_head)
 			cmdptr = (cmdptr+1) % KDB_CMD_HISTORY_COUNT;
-		strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
+		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
 		return 1;
 	}
 	return 0;
@@ -1139,7 +1145,7 @@ static void kdb_dumpregs(struct pt_regs *regs)
 	console_loglevel = old_lvl;
 }
 
-void kdb_set_current_task(struct task_struct *p)
+static void kdb_set_current_task(struct task_struct *p)
 {
 	kdb_current_task = p;
 
@@ -1299,12 +1305,9 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
 		*(cmd_hist[cmd_head]) = '\0';
 
 do_full_getstr:
-#if defined(CONFIG_SMP)
+		/* PROMPT can only be set if we have MEM_READ permission. */
 		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
 			 raw_smp_processor_id());
-#else
-		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"));
-#endif
 		if (defcmd_in_progress)
 			strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
 
@@ -1315,7 +1318,7 @@ do_full_getstr:
 		if (*cmdbuf != '\n') {
 			if (*cmdbuf < 32) {
 				if (cmdptr == cmd_head) {
-					strncpy(cmd_hist[cmd_head], cmd_cur,
+					strscpy(cmd_hist[cmd_head], cmd_cur,
 						CMD_BUFLEN);
 					*(cmd_hist[cmd_head] +
 					  strlen(cmd_hist[cmd_head])-1) = '\0';
@@ -1325,7 +1328,7 @@ do_full_getstr:
 				cmdbuf = cmd_cur;
 				goto do_full_getstr;
 			} else {
-				strncpy(cmd_hist[cmd_head], cmd_cur,
+				strscpy(cmd_hist[cmd_head], cmd_cur,
 					CMD_BUFLEN);
 			}
 
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 55d052061ef9..2e296e4a234c 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -240,8 +240,8 @@ extern void *debug_kmalloc(size_t size, gfp_t flags);
 extern void debug_kfree(void *);
 extern void debug_kusage(void);
 
-extern void kdb_set_current_task(struct task_struct *);
 extern struct task_struct *kdb_current_task;
+extern struct pt_regs *kdb_current_regs;
 
 #ifdef CONFIG_KDB_KEYBOARD
 extern void kdb_kbd_cleanup_state(void);