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authorJason Wessel <jason.wessel@windriver.com>2011-05-23 13:17:41 -0500
committerJason Wessel <jason.wessel@windriver.com>2011-08-01 13:23:59 -0500
commitf679c4985bb2e7de9d39a5d40b6031361c4ad861 (patch)
tree9750abdc0f876f38642c06c188b152324c512fdb /kernel/debug/gdbstub.c
parent3bdb65ec95e6cccffc40102d7c003047c45da90c (diff)
downloadlinux-f679c4985bb2e7de9d39a5d40b6031361c4ad861.tar.bz2
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/gdbstub.c')
-rw-r--r--kernel/debug/gdbstub.c22
1 files changed, 15 insertions, 7 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);