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authorPaul Mundt <lethal@linux-sh.org>2007-03-08 17:27:37 +0900
committerPaul Mundt <lethal@hera.kernel.org>2007-05-07 02:10:51 +0000
commitfa5da2f7bdcf885efe65a37df13907c7d72296f6 (patch)
tree54104d5f660a1ec824505b28540eb2c5e4be390a /arch/sh/kernel/kgdb_stub.c
parent15700770ef7c5d12e2f1659d2ddbeb3f658d9f37 (diff)
sh: Bring kgdb back from the dead.
This code has suffered quite a bit of bitrot, do some basic tidying to get it to a reasonably functional state again. This gets the basic support and the console working again. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel/kgdb_stub.c')
-rw-r--r--arch/sh/kernel/kgdb_stub.c106
1 files changed, 54 insertions, 52 deletions
diff --git a/arch/sh/kernel/kgdb_stub.c b/arch/sh/kernel/kgdb_stub.c
index d8927d85492..737eadc8ce0 100644
--- a/arch/sh/kernel/kgdb_stub.c
+++ b/arch/sh/kernel/kgdb_stub.c
@@ -6,11 +6,11 @@
* David Grothe <dave@gcom.com>, Tigran Aivazian <tigran@sco.com>,
* Amit S. Kale <akale@veritas.com>, William Gatliff <bgat@open-widgets.com>,
* Ben Lee, Steve Chamberlain and Benoit Miller <fulg@iname.com>.
- *
+ *
* This version by Henry Bell <henry.bell@st.com>
* Minor modifications by Jeremy Siegel <jsiegel@mvista.com>
- *
- * Contains low-level support for remote debug using GDB.
+ *
+ * Contains low-level support for remote debug using GDB.
*
* To enable debugger support, two things need to happen. A call to
* set_debug_traps() is necessary in order to allow any breakpoints
@@ -48,7 +48,7 @@
* k kill (Detach GDB)
*
* d Toggle debug flag
- * D Detach GDB
+ * D Detach GDB
*
* Hct Set thread t for operations, OK or ENN
* c = 'c' (step, cont), c = 'g' (other
@@ -58,7 +58,7 @@
* qfThreadInfo Get list of current threads (first) m<id>
* qsThreadInfo " " " " " (subsequent)
* qOffsets Get section offsets Text=x;Data=y;Bss=z
- *
+ *
* TXX Find if thread XX is alive OK or ENN
* ? What was the last sigval ? SNN (signal NN)
* O Output to GDB console
@@ -74,7 +74,7 @@
* '$' or '#'. If <data> starts with two characters followed by
* ':', then the existing stubs interpret this as a sequence number.
*
- * CSUM1 and CSUM2 are ascii hex representation of an 8-bit
+ * CSUM1 and CSUM2 are ascii hex representation of an 8-bit
* checksum of <data>, the most significant nibble is sent first.
* the hex digits 0-9,a-f are used.
*
@@ -86,8 +86,8 @@
* Responses can be run-length encoded to save space. A '*' means that
* the next character is an ASCII encoding giving a repeat count which
* stands for that many repititions of the character preceding the '*'.
- * The encoding is n+29, yielding a printable character where n >=3
- * (which is where RLE starts to win). Don't use an n > 126.
+ * The encoding is n+29, yielding a printable character where n >=3
+ * (which is where RLE starts to win). Don't use an n > 126.
*
* So "0* " means the same as "0000".
*/
@@ -100,12 +100,10 @@
#include <linux/delay.h>
#include <linux/linkage.h>
#include <linux/init.h>
-
-#ifdef CONFIG_SH_KGDB_CONSOLE
#include <linux/console.h>
-#endif
-
+#include <linux/sysrq.h>
#include <asm/system.h>
+#include <asm/cacheflush.h>
#include <asm/current.h>
#include <asm/signal.h>
#include <asm/pgtable.h>
@@ -153,7 +151,6 @@ char kgdb_in_gdb_mode;
char in_nmi; /* Set during NMI to prevent reentry */
int kgdb_nofault; /* Boolean to ignore bus errs (i.e. in GDB) */
int kgdb_enabled = 1; /* Default to enabled, cmdline can disable */
-int kgdb_halt;
/* Exposed for user access */
struct task_struct *kgdb_current;
@@ -328,7 +325,7 @@ static int hex_to_int(char **ptr, int *int_value)
}
/* Copy the binary array pointed to by buf into mem. Fix $, #,
- and 0x7d escaped with 0x7d. Return a pointer to the character
+ and 0x7d escaped with 0x7d. Return a pointer to the character
after the last byte written. */
static char *ebin_to_mem(const char *buf, char *mem, int count)
{
@@ -452,7 +449,7 @@ static void get_packet(char *buffer, int buflen)
/* Ack successful transfer */
put_debug_char('+');
- /* If a sequence char is present, reply
+ /* If a sequence char is present, reply
the sequence ID */
if (buffer[2] == ':') {
put_debug_char(buffer[0]);
@@ -759,7 +756,7 @@ static short *get_step_address(void)
return (short *) addr;
}
-/* Set up a single-step. Replace the instruction immediately after the
+/* Set up a single-step. Replace the instruction immediately after the
current instruction (i.e. next in the expected flow of control) with a
trap instruction, so that returning will cause only a single instruction
to be executed. Note that this model is slightly broken for instructions
@@ -1002,10 +999,8 @@ void set_thread_msg(void)
char *ptr;
switch (in_buffer[1]) {
-
- /* To select which thread for gG etc messages, i.e. supported */
+ /* To select which thread for gG etc messages, i.e. supported */
case 'g':
-
ptr = &in_buffer[2];
hex_to_int(&ptr, &threadid);
thread = get_thread(threadid);
@@ -1173,6 +1168,7 @@ static void query_msg(void)
}
#endif /* CONFIG_KGDB_THREAD */
+#ifdef CONFIG_SH_KGDB_CONSOLE
/*
* Bring up the ports..
*/
@@ -1185,6 +1181,9 @@ static int kgdb_serial_setup(void)
return 0;
}
+#else
+#define kgdb_serial_setup() 0
+#endif
/* The command loop, read and act on requests */
static void kgdb_command_loop(const int excep_code, const int trapa_value)
@@ -1193,7 +1192,7 @@ static void kgdb_command_loop(const int excep_code, const int trapa_value)
if (excep_code == NMI_VEC) {
#ifndef CONFIG_KGDB_NMI
- KGDB_PRINTK("Ignoring unexpected NMI?\n");
+ printk(KERN_NOTICE "KGDB: Ignoring unexpected NMI?\n");
return;
#else /* CONFIG_KGDB_NMI */
if (!kgdb_enabled) {
@@ -1216,10 +1215,7 @@ static void kgdb_command_loop(const int excep_code, const int trapa_value)
/* Enter GDB mode (e.g. after detach) */
if (!kgdb_in_gdb_mode) {
/* Do serial setup, notify user, issue preemptive ack */
- kgdb_serial_setup();
- KGDB_PRINTK("Waiting for GDB (on %s%d at %d baud)\n",
- (kgdb_porttype ? kgdb_porttype->name : ""),
- kgdb_portnum, kgdb_baud);
+ printk(KERN_NOTICE "KGDB: Waiting for GDB\n");
kgdb_in_gdb_mode = 1;
put_debug_char('+');
}
@@ -1233,21 +1229,18 @@ static void kgdb_command_loop(const int excep_code, const int trapa_value)
will later be replaced by its original one. Do NOT do this for
trap 0xff, since that indicates a compiled-in breakpoint which
will not be replaced (and we would retake the trap forever) */
- if ((excep_code == TRAP_VEC) && (trapa_value != (0xff << 2))) {
+ if ((excep_code == TRAP_VEC) && (trapa_value != (0x3c << 2)))
trap_registers.pc -= 2;
- }
/* Undo any stepping we may have done */
undo_single_step();
while (1) {
-
out_buffer[0] = 0;
get_packet(in_buffer, BUFMAX);
/* Examine first char of buffer to see what we need to do */
switch (in_buffer[0]) {
-
case '?': /* Send which signal we've received */
send_signal_msg(sigval);
break;
@@ -1323,11 +1316,8 @@ static void kgdb_command_loop(const int excep_code, const int trapa_value)
}
/* There has been an exception, most likely a breakpoint. */
-asmlinkage void kgdb_handle_exception(unsigned long r4, unsigned long r5,
- unsigned long r6, unsigned long r7,
- struct pt_regs __regs)
+static void handle_exception(struct pt_regs *regs)
{
- struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
int excep_code, vbr_val;
int count;
int trapa_value = ctrl_inl(TRA);
@@ -1355,7 +1345,7 @@ asmlinkage void kgdb_handle_exception(unsigned long r4, unsigned long r5,
kgdb_trapa_val = trapa_value;
/* Act on the exception */
- kgdb_command_loop(excep_code >> 5, trapa_value);
+ kgdb_command_loop(excep_code, trapa_value);
kgdb_current = NULL;
@@ -1373,14 +1363,12 @@ asmlinkage void kgdb_handle_exception(unsigned long r4, unsigned long r5,
asm("ldc %0, vbr": :"r"(vbr_val));
}
-/* Trigger a breakpoint by function */
-void breakpoint(void)
+asmlinkage void kgdb_handle_exception(unsigned long r4, unsigned long r5,
+ unsigned long r6, unsigned long r7,
+ struct pt_regs __regs)
{
- if (!kgdb_enabled) {
- kgdb_enabled = 1;
- kgdb_init();
- }
- BREAKPOINT();
+ struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
+ handle_exception(regs);
}
/* Initialise the KGDB data structures and serial configuration */
@@ -1395,24 +1383,16 @@ int kgdb_init(void)
kgdb_in_gdb_mode = 0;
if (kgdb_serial_setup() != 0) {
- KGDB_PRINTK("serial setup error\n");
+ printk(KERN_NOTICE "KGDB: serial setup error\n");
return -1;
}
/* Init ptr to exception handler */
- kgdb_debug_hook = kgdb_handle_exception;
+ kgdb_debug_hook = handle_exception;
kgdb_bus_err_hook = kgdb_handle_bus_error;
/* Enter kgdb now if requested, or just report init done */
- if (kgdb_halt) {
- kgdb_in_gdb_mode = 1;
- put_debug_char('+');
- breakpoint();
- }
- else
- {
- KGDB_PRINTK("stub is initialized.\n");
- }
+ printk(KERN_NOTICE "KGDB: stub is initialized.\n");
return 0;
}
@@ -1437,7 +1417,7 @@ static void kgdb_msg_write(const char *s, unsigned count)
/* Calculate how many this time */
wcount = (count > MAXOUT) ? MAXOUT : count;
-
+
/* Pack in hex chars */
for (i = 0; i < wcount; i++)
bufptr = pack_hex_byte(bufptr, s[i]);
@@ -1467,3 +1447,25 @@ void kgdb_console_write(struct console *co, const char *s, unsigned count)
kgdb_msg_write(s, count);
}
#endif
+
+#ifdef CONFIG_KGDB_SYSRQ
+static void sysrq_handle_gdb(int key, struct tty_struct *tty)
+{
+ printk("Entering GDB stub\n");
+ breakpoint();
+}
+
+static struct sysrq_key_op sysrq_gdb_op = {
+ .handler = sysrq_handle_gdb,
+ .help_msg = "Gdb",
+ .action_msg = "GDB",
+};
+
+static int gdb_register_sysrq(void)
+{
+ printk("Registering GDB sysrq handler\n");
+ register_sysrq_key('g', &sysrq_gdb_op);
+ return 0;
+}
+module_init(gdb_register_sysrq);
+#endif