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authorJason Wessel <jason.wessel@windriver.com>2011-05-23 22:17:41 +0400
committerJason Wessel <jason.wessel@windriver.com>2011-08-01 22:23:59 +0400
commitf679c4985bb2e7de9d39a5d40b6031361c4ad861 (patch)
tree9750abdc0f876f38642c06c188b152324c512fdb /kernel/debug
parent3bdb65ec95e6cccffc40102d7c003047c45da90c (diff)
downloadlinux-f679c4985bb2e7de9d39a5d40b6031361c4ad861.tar.xz
kdb,kgdb: Implement switch and pass buffer from kdb -> gdb
When switching from kdb mode to kgdb mode packets were getting lost depending on the size of the fifo queue of the serial chip. When gdb initially connects if it is in kdb mode it should entirely send any character buffer over to the gdbstub when switching connections. Previously kdb was zero'ing out the character buffer and this could lead to gdb failing to connect at all, or a lengthy pause could occur on the initial connect. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Diffstat (limited to 'kernel/debug')
-rw-r--r--kernel/debug/gdbstub.c22
-rw-r--r--kernel/debug/kdb/kdb_debugger.c17
-rw-r--r--kernel/debug/kdb/kdb_io.c10
-rw-r--r--kernel/debug/kdb/kdb_private.h1
4 files changed, 29 insertions, 21 deletions
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index a11db956dd62..34872482315e 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -42,6 +42,8 @@
/* Our I/O buffers. */
static char remcom_in_buffer[BUFMAX];
static char remcom_out_buffer[BUFMAX];
+static int gdbstub_use_prev_in_buf;
+static int gdbstub_prev_in_buf_pos;
/* Storage for the registers, in GDB format. */
static unsigned long gdb_regs[(NUMREGBYTES +
@@ -58,6 +60,13 @@ static int gdbstub_read_wait(void)
int ret = -1;
int i;
+ if (unlikely(gdbstub_use_prev_in_buf)) {
+ if (gdbstub_prev_in_buf_pos < gdbstub_use_prev_in_buf)
+ return remcom_in_buffer[gdbstub_prev_in_buf_pos++];
+ else
+ gdbstub_use_prev_in_buf = 0;
+ }
+
/* poll any additional I/O interfaces that are defined */
while (ret < 0)
for (i = 0; kdb_poll_funcs[i] != NULL; i++) {
@@ -109,7 +118,6 @@ static void get_packet(char *buffer)
buffer[count] = ch;
count = count + 1;
}
- buffer[count] = 0;
if (ch == '#') {
xmitcsum = hex_to_bin(gdbstub_read_wait()) << 4;
@@ -124,6 +132,7 @@ static void get_packet(char *buffer)
if (dbg_io_ops->flush)
dbg_io_ops->flush();
}
+ buffer[count] = 0;
} while (checksum != xmitcsum);
}
@@ -1082,12 +1091,11 @@ int gdbstub_state(struct kgdb_state *ks, char *cmd)
case 'c':
strcpy(remcom_in_buffer, cmd);
return 0;
- case '?':
- gdb_cmd_status(ks);
- break;
- case '\0':
- strcpy(remcom_out_buffer, "");
- break;
+ case '$':
+ strcpy(remcom_in_buffer, cmd);
+ gdbstub_use_prev_in_buf = strlen(remcom_in_buffer);
+ gdbstub_prev_in_buf_pos = 0;
+ return 0;
}
dbg_io_ops->write_char('+');
put_packet(remcom_out_buffer);
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index dd0b1b7dd02c..fe422d275782 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -30,6 +30,8 @@ EXPORT_SYMBOL_GPL(kdb_poll_funcs);
int kdb_poll_idx = 1;
EXPORT_SYMBOL_GPL(kdb_poll_idx);
+static struct kgdb_state *kdb_ks;
+
int kdb_stub(struct kgdb_state *ks)
{
int error = 0;
@@ -39,6 +41,7 @@ int kdb_stub(struct kgdb_state *ks)
kdb_dbtrap_t db_result = KDB_DB_NOBPT;
int i;
+ kdb_ks = ks;
if (KDB_STATE(REENTRY)) {
reason = KDB_REASON_SWITCH;
KDB_STATE_CLEAR(REENTRY);
@@ -124,16 +127,6 @@ int kdb_stub(struct kgdb_state *ks)
kdbnearsym_cleanup();
if (error == KDB_CMD_KGDB) {
if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) {
- /*
- * This inteface glue which allows kdb to transition in into
- * the gdb stub. In order to do this the '?' or '' gdb serial
- * packet response is processed here. And then control is
- * passed to the gdbstub.
- */
- if (KDB_STATE(DOING_KGDB))
- gdbstub_state(ks, "?");
- else
- gdbstub_state(ks, "");
KDB_STATE_CLEAR(DOING_KGDB);
KDB_STATE_CLEAR(DOING_KGDB2);
}
@@ -166,3 +159,7 @@ int kdb_stub(struct kgdb_state *ks)
return kgdb_info[ks->cpu].ret_state;
}
+void kdb_gdb_state_pass(char *buf)
+{
+ gdbstub_state(kdb_ks, buf);
+}
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 96fdaac46a80..bd233264b29f 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -35,8 +35,8 @@ static void kgdb_transition_check(char *buffer)
{
int slen = strlen(buffer);
if (strncmp(buffer, "$?#3f", slen) != 0 &&
- strncmp(buffer, "$qSupported#37", slen) != 0 &&
- strncmp(buffer, "+$qSupported#37", slen) != 0) {
+ strncmp(buffer, "$qSupported", slen) != 0 &&
+ strncmp(buffer, "+$qSupported", slen) != 0) {
KDB_STATE_SET(KGDB_TRANS);
kdb_printf("%s", buffer);
}
@@ -390,12 +390,14 @@ poll_again:
/* Special escape to kgdb */
if (lastchar - buffer >= 5 &&
strcmp(lastchar - 5, "$?#3f") == 0) {
+ kdb_gdb_state_pass(lastchar - 5);
strcpy(buffer, "kgdb");
KDB_STATE_SET(DOING_KGDB);
return buffer;
}
- if (lastchar - buffer >= 14 &&
- strcmp(lastchar - 14, "$qSupported#37") == 0) {
+ if (lastchar - buffer >= 11 &&
+ strcmp(lastchar - 11, "$qSupported") == 0) {
+ kdb_gdb_state_pass(lastchar - 11);
strcpy(buffer, "kgdb");
KDB_STATE_SET(DOING_KGDB2);
return buffer;
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 35d69ed1dfb5..03d332e63442 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -218,6 +218,7 @@ extern void kdb_print_nameval(const char *name, unsigned long val);
extern void kdb_send_sig_info(struct task_struct *p, struct siginfo *info);
extern void kdb_meminfo_proc_show(void);
extern char *kdb_getstr(char *, size_t, char *);
+extern void kdb_gdb_state_pass(char *buf);
/* Defines for kdb_symbol_print */
#define KDB_SP_SPACEB 0x0001 /* Space before string */