gdbstub: Implement gdbserial 'p' and 'P' packets
[sfrench/cifs-2.6.git] / kernel / debug / gdbstub.c
index 4b17b32695259060260f9748d2c51490397c4888..4ef9dddf4588a33196104e079292fb1b3198948d 100644 (file)
@@ -52,17 +52,6 @@ static unsigned long         gdb_regs[(NUMREGBYTES +
  * GDB remote protocol parser:
  */
 
-static int hex(char ch)
-{
-       if ((ch >= 'a') && (ch <= 'f'))
-               return ch - 'a' + 10;
-       if ((ch >= '0') && (ch <= '9'))
-               return ch - '0';
-       if ((ch >= 'A') && (ch <= 'F'))
-               return ch - 'A' + 10;
-       return -1;
-}
-
 #ifdef CONFIG_KGDB_KDB
 static int gdbstub_read_wait(void)
 {
@@ -123,8 +112,8 @@ static void get_packet(char *buffer)
                buffer[count] = 0;
 
                if (ch == '#') {
-                       xmitcsum = hex(gdbstub_read_wait()) << 4;
-                       xmitcsum += hex(gdbstub_read_wait());
+                       xmitcsum = hex_to_bin(gdbstub_read_wait()) << 4;
+                       xmitcsum += hex_to_bin(gdbstub_read_wait());
 
                        if (checksum != xmitcsum)
                                /* failed checksum */
@@ -236,7 +225,7 @@ void gdbstub_msg_write(const char *s, int len)
  * buf.  Return a pointer to the last char put in buf (null). May
  * return an error.
  */
-int kgdb_mem2hex(char *mem, char *buf, int count)
+char *kgdb_mem2hex(char *mem, char *buf, int count)
 {
        char *tmp;
        int err;
@@ -248,17 +237,16 @@ int kgdb_mem2hex(char *mem, char *buf, int count)
        tmp = buf + count;
 
        err = probe_kernel_read(tmp, mem, count);
-       if (!err) {
-               while (count > 0) {
-                       buf = pack_hex_byte(buf, *tmp);
-                       tmp++;
-                       count--;
-               }
-
-               *buf = 0;
+       if (err)
+               return NULL;
+       while (count > 0) {
+               buf = pack_hex_byte(buf, *tmp);
+               tmp++;
+               count--;
        }
+       *buf = 0;
 
-       return err;
+       return buf;
 }
 
 /*
@@ -280,8 +268,8 @@ int kgdb_hex2mem(char *buf, char *mem, int count)
        tmp_hex = tmp_raw - 1;
        while (tmp_hex >= buf) {
                tmp_raw--;
-               *tmp_raw = hex(*tmp_hex--);
-               *tmp_raw |= hex(*tmp_hex--) << 4;
+               *tmp_raw = hex_to_bin(*tmp_hex--);
+               *tmp_raw |= hex_to_bin(*tmp_hex--) << 4;
        }
 
        return probe_kernel_write(mem, tmp_raw, count);
@@ -304,7 +292,7 @@ int kgdb_hex2long(char **ptr, unsigned long *long_val)
                (*ptr)++;
        }
        while (**ptr) {
-               hex_val = hex(**ptr);
+               hex_val = hex_to_bin(**ptr);
                if (hex_val < 0)
                        break;
 
@@ -339,6 +327,32 @@ static int kgdb_ebin2mem(char *buf, char *mem, int count)
        return probe_kernel_write(mem, c, size);
 }
 
+#if DBG_MAX_REG_NUM > 0
+void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+       int i;
+       int idx = 0;
+       char *ptr = (char *)gdb_regs;
+
+       for (i = 0; i < DBG_MAX_REG_NUM; i++) {
+               dbg_get_reg(i, ptr + idx, regs);
+               idx += dbg_reg_def[i].size;
+       }
+}
+
+void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+       int i;
+       int idx = 0;
+       char *ptr = (char *)gdb_regs;
+
+       for (i = 0; i < DBG_MAX_REG_NUM; i++) {
+               dbg_set_reg(i, ptr + idx, regs);
+               idx += dbg_reg_def[i].size;
+       }
+}
+#endif /* DBG_MAX_REG_NUM > 0 */
+
 /* Write memory due to an 'M' or 'X' packet. */
 static int write_mem_msg(int binary)
 {
@@ -378,28 +392,31 @@ static void error_packet(char *pkt, int error)
  * remapped to negative TIDs.
  */
 
-#define BUF_THREAD_ID_SIZE     16
+#define BUF_THREAD_ID_SIZE     8
 
 static char *pack_threadid(char *pkt, unsigned char *id)
 {
-       char *limit;
+       unsigned char *limit;
+       int lzero = 1;
+
+       limit = id + (BUF_THREAD_ID_SIZE / 2);
+       while (id < limit) {
+               if (!lzero || *id != 0) {
+                       pkt = pack_hex_byte(pkt, *id);
+                       lzero = 0;
+               }
+               id++;
+       }
 
-       limit = pkt + BUF_THREAD_ID_SIZE;
-       while (pkt < limit)
-               pkt = pack_hex_byte(pkt, *id++);
+       if (lzero)
+               pkt = pack_hex_byte(pkt, 0);
 
        return pkt;
 }
 
 static void int_to_threadref(unsigned char *id, int value)
 {
-       unsigned char *scan;
-       int i = 4;
-
-       scan = (unsigned char *)id;
-       while (i--)
-               *scan++ = 0;
-       put_unaligned_be32(value, scan);
+       put_unaligned_be32(value, id);
 }
 
 static struct task_struct *getthread(struct pt_regs *regs, int tid)
@@ -463,8 +480,7 @@ static void gdb_cmd_status(struct kgdb_state *ks)
        pack_hex_byte(&remcom_out_buffer[1], ks->signo);
 }
 
-/* Handle the 'g' get registers request */
-static void gdb_cmd_getregs(struct kgdb_state *ks)
+static void gdb_get_regs_helper(struct kgdb_state *ks)
 {
        struct task_struct *thread;
        void *local_debuggerinfo;
@@ -505,6 +521,12 @@ static void gdb_cmd_getregs(struct kgdb_state *ks)
                 */
                sleeping_thread_to_gdb_regs(gdb_regs, thread);
        }
+}
+
+/* Handle the 'g' get registers request */
+static void gdb_cmd_getregs(struct kgdb_state *ks)
+{
+       gdb_get_regs_helper(ks);
        kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
 }
 
@@ -527,13 +549,13 @@ static void gdb_cmd_memread(struct kgdb_state *ks)
        char *ptr = &remcom_in_buffer[1];
        unsigned long length;
        unsigned long addr;
-       int err;
+       char *err;
 
        if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
                                        kgdb_hex2long(&ptr, &length) > 0) {
                err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
-               if (err)
-                       error_packet(remcom_out_buffer, err);
+               if (!err)
+                       error_packet(remcom_out_buffer, -EINVAL);
        } else {
                error_packet(remcom_out_buffer, -EINVAL);
        }
@@ -550,6 +572,52 @@ static void gdb_cmd_memwrite(struct kgdb_state *ks)
                strcpy(remcom_out_buffer, "OK");
 }
 
+#if DBG_MAX_REG_NUM > 0
+static char *gdb_hex_reg_helper(int regnum, char *out)
+{
+       int i;
+       int offset = 0;
+
+       for (i = 0; i < regnum; i++)
+               offset += dbg_reg_def[i].size;
+       return kgdb_mem2hex((char *)gdb_regs + offset, out,
+                           dbg_reg_def[i].size);
+}
+
+/* Handle the 'p' individual regster get */
+static void gdb_cmd_reg_get(struct kgdb_state *ks)
+{
+       unsigned long regnum;
+       char *ptr = &remcom_in_buffer[1];
+
+       kgdb_hex2long(&ptr, &regnum);
+       if (regnum >= DBG_MAX_REG_NUM) {
+               error_packet(remcom_out_buffer, -EINVAL);
+               return;
+       }
+       gdb_get_regs_helper(ks);
+       gdb_hex_reg_helper(regnum, remcom_out_buffer);
+}
+
+/* Handle the 'P' individual regster set */
+static void gdb_cmd_reg_set(struct kgdb_state *ks)
+{
+       unsigned long regnum;
+       char *ptr = &remcom_in_buffer[1];
+
+       kgdb_hex2long(&ptr, &regnum);
+       if (*ptr++ != '=' ||
+           !(!kgdb_usethread || kgdb_usethread == current) ||
+           !dbg_get_reg(regnum, gdb_regs, ks->linux_regs)) {
+               error_packet(remcom_out_buffer, -EINVAL);
+               return;
+       }
+       kgdb_hex2mem(ptr, (char *)gdb_regs, dbg_reg_def[regnum].size);
+       dbg_set_reg(regnum, gdb_regs, ks->linux_regs);
+       strcpy(remcom_out_buffer, "OK");
+}
+#endif /* DBG_MAX_REG_NUM > 0 */
+
 /* Handle the 'X' memory binary write bytes */
 static void gdb_cmd_binwrite(struct kgdb_state *ks)
 {
@@ -612,7 +680,7 @@ static void gdb_cmd_query(struct kgdb_state *ks)
 {
        struct task_struct *g;
        struct task_struct *p;
-       unsigned char thref[8];
+       unsigned char thref[BUF_THREAD_ID_SIZE];
        char *ptr;
        int i;
        int cpu;
@@ -621,10 +689,8 @@ static void gdb_cmd_query(struct kgdb_state *ks)
        switch (remcom_in_buffer[1]) {
        case 's':
        case 'f':
-               if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) {
-                       error_packet(remcom_out_buffer, -EINVAL);
+               if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10))
                        break;
-               }
 
                i = 0;
                remcom_out_buffer[0] = 'm';
@@ -634,8 +700,7 @@ static void gdb_cmd_query(struct kgdb_state *ks)
                        for_each_online_cpu(cpu) {
                                ks->thr_query = 0;
                                int_to_threadref(thref, -cpu - 2);
-                               pack_threadid(ptr, thref);
-                               ptr += BUF_THREAD_ID_SIZE;
+                               ptr = pack_threadid(ptr, thref);
                                *(ptr++) = ',';
                                i++;
                        }
@@ -644,8 +709,7 @@ static void gdb_cmd_query(struct kgdb_state *ks)
                do_each_thread(g, p) {
                        if (i >= ks->thr_query && !finished) {
                                int_to_threadref(thref, p->pid);
-                               pack_threadid(ptr, thref);
-                               ptr += BUF_THREAD_ID_SIZE;
+                               ptr = pack_threadid(ptr, thref);
                                *(ptr++) = ',';
                                ks->thr_query++;
                                if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0)
@@ -665,10 +729,9 @@ static void gdb_cmd_query(struct kgdb_state *ks)
                pack_threadid(remcom_out_buffer + 2, thref);
                break;
        case 'T':
-               if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) {
-                       error_packet(remcom_out_buffer, -EINVAL);
+               if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16))
                        break;
-               }
+
                ks->threadid = 0;
                ptr = remcom_in_buffer + 17;
                kgdb_hex2long(&ptr, &ks->threadid);
@@ -861,11 +924,14 @@ int gdb_serial_stub(struct kgdb_state *ks)
        int error = 0;
        int tmp;
 
-       /* Clear the out buffer. */
+       /* Initialize comm buffer and globals. */
        memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
+       kgdb_usethread = kgdb_info[ks->cpu].task;
+       ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
+       ks->pass_exception = 0;
 
        if (kgdb_connected) {
-               unsigned char thref[8];
+               unsigned char thref[BUF_THREAD_ID_SIZE];
                char *ptr;
 
                /* Reply to host that an exception has occurred */
@@ -879,10 +945,6 @@ int gdb_serial_stub(struct kgdb_state *ks)
                put_packet(remcom_out_buffer);
        }
 
-       kgdb_usethread = kgdb_info[ks->cpu].task;
-       ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
-       ks->pass_exception = 0;
-
        while (1) {
                error = 0;
 
@@ -907,6 +969,14 @@ int gdb_serial_stub(struct kgdb_state *ks)
                case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
                        gdb_cmd_memwrite(ks);
                        break;
+#if DBG_MAX_REG_NUM > 0
+               case 'p': /* pXX Return gdb register XX (in hex) */
+                       gdb_cmd_reg_get(ks);
+                       break;
+               case 'P': /* PXX=aaaa Set gdb register XX to aaaa (in hex) */
+                       gdb_cmd_reg_set(ks);
+                       break;
+#endif /* DBG_MAX_REG_NUM > 0 */
                case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
                        gdb_cmd_binwrite(ks);
                        break;