* 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
* 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
* 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
* '$' 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.
*
* 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".
*/
#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>
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;
static void kgdb_to_gdb(const char *s);
-#ifdef CONFIG_KGDB_THREAD
-static struct task_struct *trapped_thread;
-static struct task_struct *current_thread;
-typedef unsigned char threadref[8];
-#define BUF_THREAD_ID_SIZE 16
-#endif
-
-
/* Convert ch to hex */
static int hex(const char ch)
{
}
/* Copy the binary array pointed to by buf into mem. Fix $, #,
- and 0x7d escaped with 0x7d. Return a pointer to the character
+ and 0x7d escaped with 0x7d. Return a pointer to the character
after the last byte written. */
static char *ebin_to_mem(const char *buf, char *mem, int count)
{
return pkt;
}
-#ifdef CONFIG_KGDB_THREAD
-
-/* Pack a thread ID */
-static char *pack_threadid(char *pkt, threadref * id)
-{
- char *limit;
- unsigned char *altid;
-
- altid = (unsigned char *) id;
-
- limit = pkt + BUF_THREAD_ID_SIZE;
- while (pkt < limit)
- pkt = pack_hex_byte(pkt, *altid++);
- return pkt;
-}
-
-/* Convert an integer into our threadref */
-static void int_to_threadref(threadref * id, const int value)
-{
- unsigned char *scan = (unsigned char *) id;
- int i = 4;
-
- while (i--)
- *scan++ = 0;
-
- *scan++ = (value >> 24) & 0xff;
- *scan++ = (value >> 16) & 0xff;
- *scan++ = (value >> 8) & 0xff;
- *scan++ = (value & 0xff);
-}
-
-/* Return a task structure ptr for a particular pid */
-static struct task_struct *get_thread(int pid)
-{
- struct task_struct *thread;
-
- /* Use PID_MAX w/gdb for pid 0 */
- if (pid == PID_MAX) pid = 0;
-
- /* First check via PID */
- thread = find_task_by_pid(pid);
-
- if (thread)
- return thread;
-
- /* Start at the start */
- thread = init_tasks[0];
-
- /* Walk along the linked list of tasks */
- do {
- if (thread->pid == pid)
- return thread;
- thread = thread->next_task;
- } while (thread != init_tasks[0]);
-
- return NULL;
-}
-
-#endif /* CONFIG_KGDB_THREAD */
-
/* Scan for the start char '$', read the packet and check the checksum */
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]);
regs->vbr = gdb_regs[VBR];
}
-#ifdef CONFIG_KGDB_THREAD
-/* Make a local copy of registers from the specified thread */
-asmlinkage void ret_from_fork(void);
-static void thread_regs_to_gdb_regs(const struct task_struct *thread,
- int *gdb_regs)
-{
- int regno;
- int *tregs;
-
- /* Initialize to zero */
- for (regno = 0; regno < MAXREG; regno++)
- gdb_regs[regno] = 0;
-
- /* Just making sure... */
- if (thread == NULL)
- return;
-
- /* A new fork has pt_regs on the stack from a fork() call */
- if (thread->thread.pc == (unsigned long)ret_from_fork) {
-
- int vbr_val;
- struct pt_regs *kregs;
- kregs = (struct pt_regs*)thread->thread.sp;
-
- gdb_regs[R0] = kregs->regs[R0];
- gdb_regs[R1] = kregs->regs[R1];
- gdb_regs[R2] = kregs->regs[R2];
- gdb_regs[R3] = kregs->regs[R3];
- gdb_regs[R4] = kregs->regs[R4];
- gdb_regs[R5] = kregs->regs[R5];
- gdb_regs[R6] = kregs->regs[R6];
- gdb_regs[R7] = kregs->regs[R7];
- gdb_regs[R8] = kregs->regs[R8];
- gdb_regs[R9] = kregs->regs[R9];
- gdb_regs[R10] = kregs->regs[R10];
- gdb_regs[R11] = kregs->regs[R11];
- gdb_regs[R12] = kregs->regs[R12];
- gdb_regs[R13] = kregs->regs[R13];
- gdb_regs[R14] = kregs->regs[R14];
- gdb_regs[R15] = kregs->regs[R15];
- gdb_regs[PC] = kregs->pc;
- gdb_regs[PR] = kregs->pr;
- gdb_regs[GBR] = kregs->gbr;
- gdb_regs[MACH] = kregs->mach;
- gdb_regs[MACL] = kregs->macl;
- gdb_regs[SR] = kregs->sr;
-
- asm("stc vbr, %0":"=r"(vbr_val));
- gdb_regs[VBR] = vbr_val;
- return;
- }
-
- /* Otherwise, we have only some registers from switch_to() */
- tregs = (int *)thread->thread.sp;
- gdb_regs[R15] = (int)tregs;
- gdb_regs[R14] = *tregs++;
- gdb_regs[R13] = *tregs++;
- gdb_regs[R12] = *tregs++;
- gdb_regs[R11] = *tregs++;
- gdb_regs[R10] = *tregs++;
- gdb_regs[R9] = *tregs++;
- gdb_regs[R8] = *tregs++;
- gdb_regs[PR] = *tregs++;
- gdb_regs[GBR] = *tregs++;
- gdb_regs[PC] = thread->thread.pc;
-}
-#endif /* CONFIG_KGDB_THREAD */
-
/* Calculate the new address for after a step */
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
/* Send a signal message */
static void send_signal_msg(const int signum)
{
-#ifndef CONFIG_KGDB_THREAD
out_buffer[0] = 'S';
out_buffer[1] = highhex(signum);
out_buffer[2] = lowhex(signum);
out_buffer[3] = 0;
put_packet(out_buffer);
-#else /* CONFIG_KGDB_THREAD */
- int threadid;
- threadref thref;
- char *out = out_buffer;
- const char *tstring = "thread";
-
- *out++ = 'T';
- *out++ = highhex(signum);
- *out++ = lowhex(signum);
-
- while (*tstring) {
- *out++ = *tstring++;
- }
- *out++ = ':';
-
- threadid = trapped_thread->pid;
- if (threadid == 0) threadid = PID_MAX;
- int_to_threadref(&thref, threadid);
- pack_threadid(out, &thref);
- out += BUF_THREAD_ID_SIZE;
- *out++ = ';';
-
- *out = 0;
- put_packet(out_buffer);
-#endif /* CONFIG_KGDB_THREAD */
}
/* Reply that all was well */
/* Send register contents */
static void send_regs_msg(void)
{
-#ifdef CONFIG_KGDB_THREAD
- if (!current_thread)
- kgdb_regs_to_gdb_regs(&trap_registers, registers);
- else
- thread_regs_to_gdb_regs(current_thread, registers);
-#else
kgdb_regs_to_gdb_regs(&trap_registers, registers);
-#endif
-
mem_to_hex((char *) registers, out_buffer, NUMREGBYTES);
put_packet(out_buffer);
}
/* Set register contents - currently can't set other thread's registers */
static void set_regs_msg(void)
{
-#ifdef CONFIG_KGDB_THREAD
- if (!current_thread) {
-#endif
- kgdb_regs_to_gdb_regs(&trap_registers, registers);
- hex_to_mem(&in_buffer[1], (char *) registers, NUMREGBYTES);
- gdb_regs_to_kgdb_regs(registers, &trap_registers);
- send_ok_msg();
-#ifdef CONFIG_KGDB_THREAD
- } else
- send_err_msg();
-#endif
-}
-
-
-#ifdef CONFIG_KGDB_THREAD
-
-/* Set the status for a thread */
-void set_thread_msg(void)
-{
- int threadid;
- struct task_struct *thread = NULL;
- char *ptr;
-
- switch (in_buffer[1]) {
-
- /* 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);
-
- /* If we haven't found it */
- if (!thread) {
- send_err_msg();
- break;
- }
-
- /* Set current_thread (or not) */
- if (thread == trapped_thread)
- current_thread = NULL;
- else
- current_thread = thread;
- send_ok_msg();
- break;
-
- /* To select which thread for cCsS messages, i.e. unsupported */
- case 'c':
- send_ok_msg();
- break;
-
- default:
- send_empty_msg();
- break;
- }
-}
-
-/* Is a thread alive? */
-static void thread_status_msg(void)
-{
- char *ptr;
- int threadid;
- struct task_struct *thread = NULL;
-
- ptr = &in_buffer[1];
- hex_to_int(&ptr, &threadid);
- thread = get_thread(threadid);
- if (thread)
- send_ok_msg();
- else
- send_err_msg();
-}
-/* Send the current thread ID */
-static void thread_id_msg(void)
-{
- int threadid;
- threadref thref;
-
- out_buffer[0] = 'Q';
- out_buffer[1] = 'C';
-
- if (current_thread)
- threadid = current_thread->pid;
- else if (trapped_thread)
- threadid = trapped_thread->pid;
- else /* Impossible, but just in case! */
- {
- send_err_msg();
- return;
- }
-
- /* Translate pid 0 to PID_MAX for gdb */
- if (threadid == 0) threadid = PID_MAX;
-
- int_to_threadref(&thref, threadid);
- pack_threadid(out_buffer + 2, &thref);
- out_buffer[2 + BUF_THREAD_ID_SIZE] = '\0';
- put_packet(out_buffer);
-}
-
-/* Send thread info */
-static void thread_info_msg(void)
-{
- struct task_struct *thread = NULL;
- int threadid;
- char *pos;
- threadref thref;
-
- /* Start with 'm' */
- out_buffer[0] = 'm';
- pos = &out_buffer[1];
-
- /* For all possible thread IDs - this will overrun if > 44 threads! */
- /* Start at 1 and include PID_MAX (since GDB won't use pid 0...) */
- for (threadid = 1; threadid <= PID_MAX; threadid++) {
-
- read_lock(&tasklist_lock);
- thread = get_thread(threadid);
- read_unlock(&tasklist_lock);
-
- /* If it's a valid thread */
- if (thread) {
- int_to_threadref(&thref, threadid);
- pack_threadid(pos, &thref);
- pos += BUF_THREAD_ID_SIZE;
- *pos++ = ',';
- }
- }
- *--pos = 0; /* Lose final comma */
- put_packet(out_buffer);
-
-}
-
-/* Return printable info for gdb's 'info threads' command */
-static void thread_extra_info_msg(void)
-{
- int threadid;
- struct task_struct *thread = NULL;
- char buffer[20], *ptr;
- int i;
-
- /* Extract thread ID */
- ptr = &in_buffer[17];
- hex_to_int(&ptr, &threadid);
- thread = get_thread(threadid);
-
- /* If we don't recognise it, say so */
- if (thread == NULL)
- strcpy(buffer, "(unknown)");
- else
- strcpy(buffer, thread->comm);
-
- /* Construct packet */
- for (i = 0, ptr = out_buffer; buffer[i]; i++)
- ptr = pack_hex_byte(ptr, buffer[i]);
-
- if (thread->thread.pc == (unsigned long)ret_from_fork) {
- strcpy(buffer, "<new fork>");
- for (i = 0; buffer[i]; i++)
- ptr = pack_hex_byte(ptr, buffer[i]);
- }
-
- *ptr = '\0';
- put_packet(out_buffer);
-}
-
-/* Handle all qFooBarBaz messages - have to use an if statement as
- opposed to a switch because q messages can have > 1 char id. */
-static void query_msg(void)
-{
- const char *q_start = &in_buffer[1];
-
- /* qC = return current thread ID */
- if (strncmp(q_start, "C", 1) == 0)
- thread_id_msg();
-
- /* qfThreadInfo = query all threads (first) */
- else if (strncmp(q_start, "fThreadInfo", 11) == 0)
- thread_info_msg();
-
- /* qsThreadInfo = query all threads (subsequent). We know we have sent
- them all after the qfThreadInfo message, so there are no to send */
- else if (strncmp(q_start, "sThreadInfo", 11) == 0)
- put_packet("l"); /* el = last */
-
- /* qThreadExtraInfo = supply printable information per thread */
- else if (strncmp(q_start, "ThreadExtraInfo", 15) == 0)
- thread_extra_info_msg();
-
- /* Unsupported - empty message as per spec */
- else
- send_empty_msg();
+ kgdb_regs_to_gdb_regs(&trap_registers, registers);
+ hex_to_mem(&in_buffer[1], (char *) registers, NUMREGBYTES);
+ gdb_regs_to_kgdb_regs(registers, &trap_registers);
+ send_ok_msg();
}
-#endif /* CONFIG_KGDB_THREAD */
+#ifdef CONFIG_SH_KGDB_CONSOLE
/*
* Bring up the ports..
*/
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)
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) {
if (!kgdb_enabled)
return;
-#ifdef CONFIG_KGDB_THREAD
- /* Until GDB specifies a thread */
- current_thread = NULL;
- trapped_thread = current;
-#endif
-
/* 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('+');
}
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;
step_msg();
return;
-#ifdef CONFIG_KGDB_THREAD
-
- case 'H': /* Task related */
- set_thread_msg();
- break;
-
- case 'T': /* Query thread status */
- thread_status_msg();
- break;
-
- case 'q': /* Handle query - currently thread-related */
- query_msg();
- break;
-#endif
-
case 'k': /* 'Kill the program' with a kernel ? */
break;
}
/* There has been an exception, most likely a breakpoint. */
-void kgdb_handle_exception(struct pt_regs *regs)
+static void handle_exception(struct pt_regs *regs)
{
int excep_code, vbr_val;
int count;
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;
vbr_val = trap_registers.vbr;
asm("ldc %0, vbr": :"r"(vbr_val));
-
- return;
}
-/* 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 */
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;
}
/* 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]);
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
projects / linux-drm-fsl-dcu.git / blobdiff