From 71013521d7b195022616284aabc5e072a60c52bf Mon Sep 17 00:00:00 2001 From: Antonio Borneo Date: Fri, 3 May 2024 23:04:46 +0200 Subject: server: gdb: respect command gdb_report_register_access_error Commit 236c54c94a53 ("server/gdb_server.c: support unavailable registers") correctly returns a string of 'x' when the register is not available in the current target. While implementing this, it incorrectly drops the pre-existing feature of optionally ignoring errors while reading a register. This feature has a real use case documented in the OpenOCD manual in chapter 'Using GDB as a non-intrusive memory inspector', where GDB attaches to a target without halting it. For targets that need to be halted to read its registers, we need to hack the values of the registers returned to GDB; either returning 'xxxx' or an error causes GDB to drop the connection. Re-add the check on 'gdb_report_register_access_error' to keep the pre-existing behavior when a register error has to be ignored: - return a string of '0'; - drop a debug message. Change-Id: Ie65c92f259f92502e688914f334655b635874179 Signed-off-by: Antonio Borneo Fixes: 236c54c94a53 ("server/gdb_server.c: support unavailable registers") Reviewed-on: https://review.openocd.org/c/openocd/+/8228 Tested-by: jenkins --- src/server/gdb_server.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c index 5052bf4..7c2f41e 100644 --- a/src/server/gdb_server.c +++ b/src/server/gdb_server.c @@ -1233,6 +1233,8 @@ static int gdb_get_reg_value_as_str(struct target *target, char *tstr, struct re tstr[len] = '\0'; return ERROR_OK; } + memset(tstr, '0', len); + tstr[len] = '\0'; return ERROR_FAIL; } @@ -1277,7 +1279,9 @@ static int gdb_get_registers_packet(struct connection *connection, for (i = 0; i < reg_list_size; i++) { if (!reg_list[i] || reg_list[i]->exist == false || reg_list[i]->hidden) continue; - if (gdb_get_reg_value_as_str(target, reg_packet_p, reg_list[i]) != ERROR_OK) { + retval = gdb_get_reg_value_as_str(target, reg_packet_p, reg_list[i]); + if (retval != ERROR_OK && gdb_report_register_access_error) { + LOG_DEBUG("Couldn't get register %s.", reg_list[i]->name); free(reg_packet); free(reg_list); return gdb_error(connection, retval); @@ -1395,7 +1399,9 @@ static int gdb_get_register_packet(struct connection *connection, reg_packet = calloc(DIV_ROUND_UP(reg_list[reg_num]->size, 8) * 2 + 1, 1); /* plus one for string termination null */ - if (gdb_get_reg_value_as_str(target, reg_packet, reg_list[reg_num]) != ERROR_OK) { + retval = gdb_get_reg_value_as_str(target, reg_packet, reg_list[reg_num]); + if (retval != ERROR_OK && gdb_report_register_access_error) { + LOG_DEBUG("Couldn't get register %s.", reg_list[reg_num]->name); free(reg_packet); free(reg_list); return gdb_error(connection, retval); -- cgit v1.1