ARM: Dump memory and backtrace as one printk per line

dump_mem and dump_backtrace were both using multiple printk statements
to print each line.  With DEBUG_LL enabled, this causes OOPS to become
very difficult to read.  Solve this by only using one printk per line.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/traps.c

@@ -50,10 +50,10 @@ static void dump_mem(const char *str, unsigned long bottom, unsigned long top);
 void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
 {
 #ifdef CONFIG_KALLSYMS
-	printk("[<%08lx>] ", where);
-	print_symbol("(%s) ", where);
-	printk("from [<%08lx>] ", from);
-	print_symbol("(%s)\n", from);
+	char sym1[KSYM_SYMBOL_LEN], sym2[KSYM_SYMBOL_LEN];
+	sprint_symbol(sym1, where);
+	sprint_symbol(sym2, from);
+	printk("[<%08lx>] (%s) from [<%08lx>] (%s)\n", where, sym1, from, sym2);
 #else
 	printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
 #endif
@@ -83,7 +83,7 @@ static int verify_stack(unsigned long sp)
  */
 static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
 {
-	unsigned long p = bottom & ~31;
+	unsigned long first;
 	mm_segment_t fs;
 	int i;
 
@@ -97,20 +97,23 @@ static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
 
 	printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
 
-	for (p = bottom & ~31; p < top;) {
-		printk("%04lx: ", p & 0xffff);
+	for (first = bottom & ~31; first < top; first += 32) {
+		unsigned long p;
+		char str[sizeof(" 12345678") * 8 + 1];
 
-		for (i = 0; i < 8; i++, p += 4) {
-			unsigned int val;
+		memset(str, ' ', sizeof(str));
+		str[sizeof(str) - 1] = '\0';
 
-			if (p < bottom || p >= top)
-				printk("         ");
-			else {
-				__get_user(val, (unsigned long *)p);
-				printk("%08x ", val);
+		for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
+			if (p >= bottom && p < top) {
+				unsigned long val;
+				if (__get_user(val, (unsigned long *)p) == 0)
+					sprintf(str + i * 9, " %08lx", val);
+				else
+					sprintf(str + i * 9, " ????????");
 			}
 		}
-		printk ("\n");
+		printk("%04lx:%s\n", first & 0xffff, str);
 	}
 
 	set_fs(fs);
@@ -122,6 +125,7 @@ static void dump_instr(struct pt_regs *regs)
 	const int thumb = thumb_mode(regs);
 	const int width = thumb ? 4 : 8;
 	mm_segment_t fs;
+	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
 	int i;
 
 	/*
@@ -132,7 +136,6 @@ static void dump_instr(struct pt_regs *regs)
 	fs = get_fs();
 	set_fs(KERNEL_DS);
 
-	printk("Code: ");
 	for (i = -4; i < 1; i++) {
 		unsigned int val, bad;
 
@@ -142,13 +145,14 @@ static void dump_instr(struct pt_regs *regs)
 			bad = __get_user(val, &((u32 *)addr)[i]);
 
 		if (!bad)
-			printk(i == 0 ? "(%0*x) " : "%0*x ", width, val);
+			p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
+					width, val);
 		else {
-			printk("bad PC value.");
+			p += sprintf(p, "bad PC value");
 			break;
 		}
 	}
-	printk("\n");
+	printk("Code: %s\n", str);
 
 	set_fs(fs);
 }