kgdb: x86: Return all segment registers also in 64-bit mode

Even if the content is always 0, gdb expects us to return also ds,
es, fs, and gs while in x86-64 mode. Do this to avoid ugly errors on
"info registers".

[jason.wessel@windriver.com: adjust NUMREGBYTES for two new regs]
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

arch/x86/include/asm/kgdb.h

@@ -64,11 +64,15 @@ enum regnames {
 	GDB_PS,			/* 17 */
 	GDB_CS,			/* 18 */
 	GDB_SS,			/* 19 */
+	GDB_DS,			/* 20 */
+	GDB_ES,			/* 21 */
+	GDB_FS,			/* 22 */
+	GDB_GS,			/* 23 */
 };
 #define GDB_ORIG_AX		57
-#define DBG_MAX_REG_NUM		20
-/* 17 64 bit regs and 3 32 bit regs */
-#define NUMREGBYTES		((17 * 8) + (3 * 4))
+#define DBG_MAX_REG_NUM		24
+/* 17 64 bit regs and 5 32 bit regs */
+#define NUMREGBYTES		((17 * 8) + (5 * 4))
 #endif /* ! CONFIG_X86_32 */
 
 static inline void arch_kgdb_breakpoint(void)

arch/x86/kernel/kgdb.c

@@ -67,8 +67,6 @@ struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
 	{ "ss", 4, offsetof(struct pt_regs, ss) },
 	{ "ds", 4, offsetof(struct pt_regs, ds) },
 	{ "es", 4, offsetof(struct pt_regs, es) },
-	{ "fs", 4, -1 },
-	{ "gs", 4, -1 },
 #else
 	{ "ax", 8, offsetof(struct pt_regs, ax) },
 	{ "bx", 8, offsetof(struct pt_regs, bx) },
@@ -90,7 +88,11 @@ struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
 	{ "flags", 4, offsetof(struct pt_regs, flags) },
 	{ "cs", 4, offsetof(struct pt_regs, cs) },
 	{ "ss", 4, offsetof(struct pt_regs, ss) },
+	{ "ds", 4, -1 },
+	{ "es", 4, -1 },
 #endif
+	{ "fs", 4, -1 },
+	{ "gs", 4, -1 },
 };
 
 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)