Merge tag 'kgdb-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux

Pull kgdb updates from Daniel Thompson:
 "A collection of small cleanups this cycle.

  Thorsten Blum has replaced a number strcpy() calls with safer
  alternatives (fixing a pointer aliasing bug in the process).

  Colin Ian King has simplified things by removing some unreachable
  code"

* tag 'kgdb-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
  kdb: remove redundant check for scancode 0xe0
  kdb: Replace deprecated strcpy() with helper function in kdb_defcmd()
  kdb: Replace deprecated strcpy() with memcpy() in parse_grep()
  kdb: Replace deprecated strcpy() with memmove() in vkdb_printf()
  kdb: Replace deprecated strcpy() with memcpy() in kdb_strdup()
  kernel: debug: gdbstub: Replace deprecated strcpy() with strscpy()

Author: torvalds

kernel/debug/gdbstub.c

@@ -30,6 +30,7 @@
 #include <linux/kgdb.h>
 #include <linux/kdb.h>
 #include <linux/serial_core.h>
+#include <linux/string.h>
 #include <linux/reboot.h>
 #include <linux/uaccess.h>
 #include <asm/cacheflush.h>
@@ -547,7 +548,7 @@ static void gdb_cmd_setregs(struct kgdb_state *ks)
 		error_packet(remcom_out_buffer, -EINVAL);
 	} else {
 		gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
-		strcpy(remcom_out_buffer, "OK");
+		strscpy(remcom_out_buffer, "OK");
 	}
 }
 
@@ -577,7 +578,7 @@ static void gdb_cmd_memwrite(struct kgdb_state *ks)
 	if (err)
 		error_packet(remcom_out_buffer, err);
 	else
-		strcpy(remcom_out_buffer, "OK");
+		strscpy(remcom_out_buffer, "OK");
 }
 
 #if DBG_MAX_REG_NUM > 0
@@ -630,7 +631,7 @@ static void gdb_cmd_reg_set(struct kgdb_state *ks)
 	i = i / 2;
 	kgdb_hex2mem(ptr, (char *)gdb_regs, i);
 	dbg_set_reg(regnum, gdb_regs, ks->linux_regs);
-	strcpy(remcom_out_buffer, "OK");
+	strscpy(remcom_out_buffer, "OK");
 }
 #endif /* DBG_MAX_REG_NUM > 0 */
 
@@ -642,7 +643,7 @@ static void gdb_cmd_binwrite(struct kgdb_state *ks)
 	if (err)
 		error_packet(remcom_out_buffer, err);
 	else
-		strcpy(remcom_out_buffer, "OK");
+		strscpy(remcom_out_buffer, "OK");
 }
 
 /* Handle the 'D' or 'k', detach or kill packets */
@@ -656,7 +657,7 @@ static void gdb_cmd_detachkill(struct kgdb_state *ks)
 		if (error < 0) {
 			error_packet(remcom_out_buffer, error);
 		} else {
-			strcpy(remcom_out_buffer, "OK");
+			strscpy(remcom_out_buffer, "OK");
 			kgdb_connected = 0;
 		}
 		put_packet(remcom_out_buffer);
@@ -676,7 +677,7 @@ static int gdb_cmd_reboot(struct kgdb_state *ks)
 	/* For now, only honor R0 */
 	if (strcmp(remcom_in_buffer, "R0") == 0) {
 		printk(KERN_CRIT "Executing emergency reboot\n");
-		strcpy(remcom_out_buffer, "OK");
+		strscpy(remcom_out_buffer, "OK");
 		put_packet(remcom_out_buffer);
 
 		/*
@@ -739,7 +740,7 @@ static void gdb_cmd_query(struct kgdb_state *ks)
 
 	case 'C':
 		/* Current thread id */
-		strcpy(remcom_out_buffer, "QC");
+		strscpy(remcom_out_buffer, "QC");
 		ks->threadid = shadow_pid(current->pid);
 		int_to_threadref(thref, ks->threadid);
 		pack_threadid(remcom_out_buffer + 2, thref);
@@ -773,7 +774,7 @@ static void gdb_cmd_query(struct kgdb_state *ks)
 			int len = strlen(remcom_in_buffer + 6);
 
 			if ((len % 2) != 0) {
-				strcpy(remcom_out_buffer, "E01");
+				strscpy(remcom_out_buffer, "E01");
 				break;
 			}
 			kgdb_hex2mem(remcom_in_buffer + 6,
@@ -785,14 +786,14 @@ static void gdb_cmd_query(struct kgdb_state *ks)
 			kdb_parse(remcom_out_buffer);
 			kdb_common_deinit_state();
 
-			strcpy(remcom_out_buffer, "OK");
+			strscpy(remcom_out_buffer, "OK");
 		}
 		break;
 #endif
 #ifdef CONFIG_HAVE_ARCH_KGDB_QXFER_PKT
 	case 'S':
 		if (!strncmp(remcom_in_buffer, "qSupported:", 11))
-			strcpy(remcom_out_buffer, kgdb_arch_gdb_stub_feature);
+			strscpy(remcom_out_buffer, kgdb_arch_gdb_stub_feature);
 		break;
 	case 'X':
 		if (!strncmp(remcom_in_buffer, "qXfer:", 6))
@@ -822,7 +823,7 @@ static void gdb_cmd_task(struct kgdb_state *ks)
 		}
 		kgdb_usethread = thread;
 		ks->kgdb_usethreadid = ks->threadid;
-		strcpy(remcom_out_buffer, "OK");
+		strscpy(remcom_out_buffer, "OK");
 		break;
 	case 'c':
 		ptr = &remcom_in_buffer[2];
@@ -837,7 +838,7 @@ static void gdb_cmd_task(struct kgdb_state *ks)
 			}
 			kgdb_contthread = thread;
 		}
-		strcpy(remcom_out_buffer, "OK");
+		strscpy(remcom_out_buffer, "OK");
 		break;
 	}
 }
@@ -851,7 +852,7 @@ static void gdb_cmd_thread(struct kgdb_state *ks)
 	kgdb_hex2long(&ptr, &ks->threadid);
 	thread = getthread(ks->linux_regs, ks->threadid);
 	if (thread)
-		strcpy(remcom_out_buffer, "OK");
+		strscpy(remcom_out_buffer, "OK");
 	else
 		error_packet(remcom_out_buffer, -EINVAL);
 }
@@ -913,7 +914,7 @@ static void gdb_cmd_break(struct kgdb_state *ks)
 			(int) length, *bpt_type - '0');
 
 	if (error == 0)
-		strcpy(remcom_out_buffer, "OK");
+		strscpy(remcom_out_buffer, "OK");
 	else
 		error_packet(remcom_out_buffer, error);
 }

kernel/debug/kdb/kdb_io.c

@@ -714,8 +714,8 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
 		 * it, depending on the results of the search.
 		 */
 		cp++;	 	     /* to byte after the newline */
-		replaced_byte = *cp; /* remember what/where it was */
-		cphold = cp;
+		replaced_byte = *cp; /* remember what it was */
+		cphold = cp;	     /* remember where it was */
 		*cp = '\0';	     /* end the string for our search */
 
 		/*
@@ -732,8 +732,9 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
 			 * Shift the buffer left.
 			 */
 			*cphold = replaced_byte;
-			strcpy(kdb_buffer, cphold);
-			len = strlen(kdb_buffer);
+			len = strlen(cphold);
+			/* Use memmove() because the buffers overlap */
+			memmove(kdb_buffer, cphold, len + 1);
 			next_avail = kdb_buffer + len;
 			size_avail = sizeof(kdb_buffer) - len;
 			goto kdb_print_out;
@@ -872,8 +873,9 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
 	 */
 	if (kdb_grepping_flag && !suspend_grep) {
 		*cphold = replaced_byte;
-		strcpy(kdb_buffer, cphold);
-		len = strlen(kdb_buffer);
+		len = strlen(cphold);
+		/* Use memmove() because the buffers overlap */
+		memmove(kdb_buffer, cphold, len + 1);
 		next_avail = kdb_buffer + len;
 		size_avail = sizeof(kdb_buffer) - len;
 	}

kernel/debug/kdb/kdb_keyboard.c

@@ -145,9 +145,6 @@ int kdb_get_kbd_char(void)
 		return CTRL('F');
 	}
 
-	if (scancode == 0xe0)
-		return -1;
-
 	/*
 	 * For Japanese 86/106 keyboards
 	 * 	See comment in drivers/char/pc_keyb.c.

kernel/debug/kdb/kdb_main.c

@@ -721,20 +721,12 @@ static int kdb_defcmd(int argc, const char **argv)
 	mp->name = kdb_strdup(argv[1], GFP_KDB);
 	if (!mp->name)
 		goto fail_name;
-	mp->usage = kdb_strdup(argv[2], GFP_KDB);
+	mp->usage = kdb_strdup_dequote(argv[2], GFP_KDB);
 	if (!mp->usage)
 		goto fail_usage;
-	mp->help = kdb_strdup(argv[3], GFP_KDB);
+	mp->help = kdb_strdup_dequote(argv[3], GFP_KDB);
 	if (!mp->help)
 		goto fail_help;
-	if (mp->usage[0] == '"') {
-		strcpy(mp->usage, argv[2]+1);
-		mp->usage[strlen(mp->usage)-1] = '\0';
-	}
-	if (mp->help[0] == '"') {
-		strcpy(mp->help, argv[3]+1);
-		mp->help[strlen(mp->help)-1] = '\0';
-	}
 
 	INIT_LIST_HEAD(&kdb_macro->statements);
 	defcmd_in_progress = true;
@@ -860,7 +852,7 @@ static void parse_grep(const char *str)
 		kdb_printf("search string too long\n");
 		return;
 	}
-	strcpy(kdb_grep_string, cp);
+	memcpy(kdb_grep_string, cp, len + 1);
 	kdb_grepping_flag++;
 	return;
 }

kernel/debug/kdb/kdb_private.h

@@ -110,6 +110,7 @@ extern int kdbgetaddrarg(int, const char **, int*, unsigned long *,
 extern int kdbgetsymval(const char *, kdb_symtab_t *);
 extern int kdbnearsym(unsigned long, kdb_symtab_t *);
 extern char *kdb_strdup(const char *str, gfp_t type);
+extern char *kdb_strdup_dequote(const char *str, gfp_t type);
 extern void kdb_symbol_print(unsigned long, const kdb_symtab_t *, unsigned int);
 
 /* Routine for debugging the debugger state. */

kernel/debug/kdb/kdb_support.c

@@ -23,6 +23,7 @@
 #include <linux/uaccess.h>
 #include <linux/kdb.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/ctype.h>
 #include "kdb_private.h"
 
@@ -246,11 +247,41 @@ void kdb_symbol_print(unsigned long addr, const kdb_symtab_t *symtab_p,
  */
 char *kdb_strdup(const char *str, gfp_t type)
 {
-	int n = strlen(str)+1;
+	size_t n = strlen(str) + 1;
 	char *s = kmalloc(n, type);
 	if (!s)
 		return NULL;
-	return strcpy(s, str);
+	memcpy(s, str, n);
+	return s;
+}
+
+/*
+ * kdb_strdup_dequote - same as kdb_strdup(), but trims surrounding quotes from
+ *			the input string if present.
+ * Remarks:
+ *	Quotes are only removed if there is both a leading and a trailing quote.
+ */
+char *kdb_strdup_dequote(const char *str, gfp_t type)
+{
+	size_t len = strlen(str);
+	char *s;
+
+	if (str[0] == '"' && len > 1 && str[len - 1] == '"') {
+		/* trim both leading and trailing quotes */
+		str++;
+		len -= 2;
+	}
+
+	len++; /* add space for NUL terminator */
+
+	s = kmalloc(len, type);
+	if (!s)
+		return NULL;
+
+	memcpy(s, str, len - 1);
+	s[len - 1] = '\0';
+
+	return s;
 }
 
 /*