Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/jwessel/linux-2.6-kgdb * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: kdb,kgdb: Allow arbitrary kgdb magic knock sequences kdb: Remove all references to DOING_KGDB2 kdb,kgdb: Implement switch and pass buffer from kdb -> gdb kdb: cleanup unused variables missed in the original kdb merge
torvalds · Aug 1, 2011 · 72f9adf · 72f9adf
2 parents 5f66d2b + 37f86b4
commit 72f9adf
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Showing 7 changed files with 53 additions and 42 deletions.
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
@@ -42,6 +42,8 @@
 /* Our I/O buffers. */
 static char			remcom_in_buffer[BUFMAX];
 static char			remcom_out_buffer[BUFMAX];
+static int			gdbstub_use_prev_in_buf;
+static int			gdbstub_prev_in_buf_pos;
 
 /* Storage for the registers, in GDB format. */
 static unsigned long		gdb_regs[(NUMREGBYTES +
@@ -58,6 +60,13 @@ static int gdbstub_read_wait(void)
 	int ret = -1;
 	int i;
 
+	if (unlikely(gdbstub_use_prev_in_buf)) {
+		if (gdbstub_prev_in_buf_pos < gdbstub_use_prev_in_buf)
+			return remcom_in_buffer[gdbstub_prev_in_buf_pos++];
+		else
+			gdbstub_use_prev_in_buf = 0;
+	}
+
 	/* poll any additional I/O interfaces that are defined */
 	while (ret < 0)
 		for (i = 0; kdb_poll_funcs[i] != NULL; i++) {
@@ -109,7 +118,6 @@ static void get_packet(char *buffer)
 			buffer[count] = ch;
 			count = count + 1;
 		}
-		buffer[count] = 0;
 
 		if (ch == '#') {
 			xmitcsum = hex_to_bin(gdbstub_read_wait()) << 4;
@@ -124,6 +132,7 @@ static void get_packet(char *buffer)
 			if (dbg_io_ops->flush)
 				dbg_io_ops->flush();
 		}
+		buffer[count] = 0;
 	} while (checksum != xmitcsum);
 }
 
@@ -1082,12 +1091,11 @@ int gdbstub_state(struct kgdb_state *ks, char *cmd)
 	case 'c':
 		strcpy(remcom_in_buffer, cmd);
 		return 0;
-	case '?':
-		gdb_cmd_status(ks);
-		break;
-	case '\0':
-		strcpy(remcom_out_buffer, "");
-		break;
+	case '$':
+		strcpy(remcom_in_buffer, cmd);
+		gdbstub_use_prev_in_buf = strlen(remcom_in_buffer);
+		gdbstub_prev_in_buf_pos = 0;
+		return 0;
 	}
 	dbg_io_ops->write_char('+');
 	put_packet(remcom_out_buffer);

diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c
@@ -112,9 +112,8 @@ kdb_bt(int argc, const char **argv)
 	unsigned long addr;
 	long offset;
 
-	kdbgetintenv("BTARGS", &argcount);	/* Arguments to print */
-	kdbgetintenv("BTAPROMPT", &btaprompt);	/* Prompt after each
-						 * proc in bta */
+	/* Prompt after each proc in bta */
+	kdbgetintenv("BTAPROMPT", &btaprompt);
 
 	if (strcmp(argv[0], "bta") == 0) {
 		struct task_struct *g, *p;

diff --git a/kernel/debug/kdb/kdb_cmds b/kernel/debug/kdb/kdb_cmds
@@ -18,16 +18,12 @@ defcmd dumpcommon "" "Common kdb debugging"
 endefcmd
 
 defcmd dumpall "" "First line debugging"
-  set BTSYMARG 1
-  set BTARGS 9
   pid R
   -dumpcommon
   -bta
 endefcmd
 
 defcmd dumpcpu "" "Same as dumpall but only tasks on cpus"
-  set BTSYMARG 1
-  set BTARGS 9
   pid R
   -dumpcommon
   -btc

diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
@@ -30,6 +30,8 @@ EXPORT_SYMBOL_GPL(kdb_poll_funcs);
 int kdb_poll_idx = 1;
 EXPORT_SYMBOL_GPL(kdb_poll_idx);
 
+static struct kgdb_state *kdb_ks;
+
 int kdb_stub(struct kgdb_state *ks)
 {
 	int error = 0;
@@ -39,6 +41,7 @@ int kdb_stub(struct kgdb_state *ks)
 	kdb_dbtrap_t db_result = KDB_DB_NOBPT;
 	int i;
 
+	kdb_ks = ks;
 	if (KDB_STATE(REENTRY)) {
 		reason = KDB_REASON_SWITCH;
 		KDB_STATE_CLEAR(REENTRY);
@@ -123,20 +126,8 @@ int kdb_stub(struct kgdb_state *ks)
 	KDB_STATE_CLEAR(PAGER);
 	kdbnearsym_cleanup();
 	if (error == KDB_CMD_KGDB) {
-		if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) {
-	/*
-	 * This inteface glue which allows kdb to transition in into
-	 * the gdb stub.  In order to do this the '?' or '' gdb serial
-	 * packet response is processed here.  And then control is
-	 * passed to the gdbstub.
-	 */
-			if (KDB_STATE(DOING_KGDB))
-				gdbstub_state(ks, "?");
-			else
-				gdbstub_state(ks, "");
+		if (KDB_STATE(DOING_KGDB))
 			KDB_STATE_CLEAR(DOING_KGDB);
-			KDB_STATE_CLEAR(DOING_KGDB2);
-		}
 		return DBG_PASS_EVENT;
 	}
 	kdb_bp_install(ks->linux_regs);
@@ -166,3 +157,7 @@ int kdb_stub(struct kgdb_state *ks)
 	return kgdb_info[ks->cpu].ret_state;
 }
 
+void kdb_gdb_state_pass(char *buf)
+{
+	gdbstub_state(kdb_ks, buf);
+}
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
@@ -31,15 +31,21 @@ char kdb_prompt_str[CMD_BUFLEN];
 
 int kdb_trap_printk;
 
-static void kgdb_transition_check(char *buffer)
+static int kgdb_transition_check(char *buffer)
 {
-	int slen = strlen(buffer);
-	if (strncmp(buffer, "$?#3f", slen) != 0 &&
-	    strncmp(buffer, "$qSupported#37", slen) != 0 &&
-	    strncmp(buffer, "+$qSupported#37", slen) != 0) {
+	if (buffer[0] != '+' && buffer[0] != '$') {
 		KDB_STATE_SET(KGDB_TRANS);
 		kdb_printf("%s", buffer);
+	} else {
+		int slen = strlen(buffer);
+		if (slen > 3 && buffer[slen - 3] == '#') {
+			kdb_gdb_state_pass(buffer);
+			strcpy(buffer, "kgdb");
+			KDB_STATE_SET(DOING_KGDB);
+			return 1;
+		}
 	}
+	return 0;
 }
 
 static int kdb_read_get_key(char *buffer, size_t bufsize)
@@ -251,6 +257,10 @@ static char *kdb_read(char *buffer, size_t bufsize)
 	case 13: /* enter */
 		*lastchar++ = '\n';
 		*lastchar++ = '\0';
+		if (!KDB_STATE(KGDB_TRANS)) {
+			KDB_STATE_SET(KGDB_TRANS);
+			kdb_printf("%s", buffer);
+		}
 		kdb_printf("\n");
 		return buffer;
 	case 4: /* Del */
@@ -382,22 +392,26 @@ static char *kdb_read(char *buffer, size_t bufsize)
 				 * printed characters if we think that
 				 * kgdb is connecting, until the check
 				 * fails */
-				if (!KDB_STATE(KGDB_TRANS))
-					kgdb_transition_check(buffer);
-				else
+				if (!KDB_STATE(KGDB_TRANS)) {
+					if (kgdb_transition_check(buffer))
+						return buffer;
+				} else {
 					kdb_printf("%c", key);
+				}
 			}
 			/* Special escape to kgdb */
 			if (lastchar - buffer >= 5 &&
 			    strcmp(lastchar - 5, "$?#3f") == 0) {
+				kdb_gdb_state_pass(lastchar - 5);
 				strcpy(buffer, "kgdb");
 				KDB_STATE_SET(DOING_KGDB);
 				return buffer;
 			}
-			if (lastchar - buffer >= 14 &&
-			    strcmp(lastchar - 14, "$qSupported#37") == 0) {
+			if (lastchar - buffer >= 11 &&
+			    strcmp(lastchar - 11, "$qSupported") == 0) {
+				kdb_gdb_state_pass(lastchar - 11);
 				strcpy(buffer, "kgdb");
-				KDB_STATE_SET(DOING_KGDB2);
+				KDB_STATE_SET(DOING_KGDB);
 				return buffer;
 			}
 		}

diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
@@ -145,7 +145,6 @@ static char *__env[] = {
 #endif
  "RADIX=16",
  "MDCOUNT=8",			/* lines of md output */
- "BTARGS=9",			/* 9 possible args in bt */
  KDB_PLATFORM_ENV,
  "DTABCOUNT=30",
  "NOSECT=1",
@@ -172,6 +171,7 @@ static char *__env[] = {
  (char *)0,
  (char *)0,
  (char *)0,
+ (char *)0,
 };
 
 static const int __nenv = (sizeof(__env) / sizeof(char *));
@@ -1386,7 +1386,7 @@ int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
 		}
 
 		if (result == KDB_CMD_KGDB) {
-			if (!(KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)))
+			if (!KDB_STATE(DOING_KGDB))
 				kdb_printf("Entering please attach debugger "
 					   "or use $D#44+ or $3#33\n");
 			break;

diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
@@ -21,7 +21,6 @@
 #define KDB_CMD_SS	(-1003)
 #define KDB_CMD_SSB	(-1004)
 #define KDB_CMD_KGDB (-1005)
-#define KDB_CMD_KGDB2 (-1006)
 
 /* Internal debug flags */
 #define KDB_DEBUG_FLAG_BP	0x0002	/* Breakpoint subsystem debug */
@@ -146,7 +145,6 @@ extern int kdb_state;
 						 * keyboard on this cpu */
 #define KDB_STATE_KEXEC		0x00040000	/* kexec issued */
 #define KDB_STATE_DOING_KGDB	0x00080000	/* kgdb enter now issued */
-#define KDB_STATE_DOING_KGDB2	0x00100000	/* kgdb enter now issued */
 #define KDB_STATE_KGDB_TRANS	0x00200000	/* Transition to kgdb */
 #define KDB_STATE_ARCH		0xff000000	/* Reserved for arch
 						 * specific use */
@@ -218,6 +216,7 @@ extern void kdb_print_nameval(const char *name, unsigned long val);
 extern void kdb_send_sig_info(struct task_struct *p, struct siginfo *info);
 extern void kdb_meminfo_proc_show(void);
 extern char *kdb_getstr(char *, size_t, char *);
+extern void kdb_gdb_state_pass(char *buf);
 
 /* Defines for kdb_symbol_print */
 #define KDB_SP_SPACEB	0x0001		/* Space before string */