[PATCH]: bca1ffb3a3 target/server: custom target-specific GDB queries, sparse register maps

[gerrit]

This is an automated email from Gerrit.

"Ian Thompson <ia...@cadence.com>" just uploaded a new patch set to Gerrit, 
which you can find at https://review.openocd.org/c/openocd/+/7082

-- gerrit

commit bca1ffb3a374fc5cf8b47b423ac4f72f0955866e
Author: Ian Thompson <ia...@cadence.com>
Date:   Sun Jul 10 17:14:10 2022 -0700

    target/server: custom target-specific GDB queries, sparse register maps
    
    The following server extensions are provided in the context of generic 
Xtensa target support:
    - Handle sparse register addressing, where gaps may exist in reg_list[]
    - Add "SW breakpoints unsupported" non-error reply for Z-packets
    - Add customizable hook for handling target-specific GDB queries
    
    Valgrind-clean, no new Clang analyzer warnings
    
    Signed-off-by: Ian Thompson <ia...@cadence.com>
    Change-Id: I684a259ed29f3651cbce668101cff421e522f79e

diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index 4efdc1ee7e..c47510bd01 100644
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -1334,6 +1334,8 @@ static int gdb_set_registers_packet(struct connection 
*connection,
        packet_p = packet;
        for (i = 0; i < reg_list_size; i++) {
                uint8_t *bin_buf;
+               if (!reg_list[i] || !reg_list[i]->exist)
+                       continue;
                int chars = (DIV_ROUND_UP(reg_list[i]->size, 8) * 2);
 
                if (packet_p + chars > packet + packet_size)
@@ -1386,7 +1388,7 @@ static int gdb_get_register_packet(struct connection 
*connection,
        if (retval != ERROR_OK)
                return gdb_error(connection, retval);
 
-       if (reg_list_size <= reg_num) {
+       if ((reg_list_size <= reg_num) || !reg_list[reg_num]) {
                LOG_ERROR("gdb requested a non-existing register (reg_num=%d)", 
reg_num);
                return ERROR_SERVER_REMOTE_CLOSED;
        }
@@ -1448,7 +1450,7 @@ static int gdb_set_register_packet(struct connection 
*connection,
                return gdb_error(connection, retval);
        }
 
-       if (reg_list_size <= reg_num) {
+       if ((reg_list_size <= reg_num) || !reg_list[reg_num]) {
                LOG_ERROR("gdb requested a non-existing register (reg_num=%d)", 
reg_num);
                free(bin_buf);
                free(reg_list);
@@ -1781,7 +1783,10 @@ static int gdb_breakpoint_watchpoint_packet(struct 
connection *connection,
                case 1:
                        if (packet[0] == 'Z') {
                                retval = breakpoint_add(target, address, size, 
bp_type);
-                               if (retval != ERROR_OK) {
+                               if (retval == ERROR_TARGET_INVALID) {
+                                       /* SW breakpoints not supported */
+                                       gdb_put_packet(connection, "", 0);
+                               } else if (retval != ERROR_OK) {
                                        retval = gdb_error(connection, retval);
                                        if (retval != ERROR_OK)
                                                return retval;
@@ -2966,6 +2971,11 @@ static int gdb_query_packet(struct connection 
*connection,
                gdb_connection->noack_mode = 1;
                gdb_put_packet(connection, "OK", 2);
                return ERROR_OK;
+       } else if (target->type->gdb_query_custom) {
+               char *buffer = NULL;
+               int ret = target->type->gdb_query_custom(target, packet, 
&buffer);
+               gdb_put_packet(connection, buffer, strlen(buffer));
+               return ret;
        }
 
        gdb_put_packet(connection, "", 0);
diff --git a/src/target/target_type.h b/src/target/target_type.h
index a26c2e7d87..82ef78e143 100644
--- a/src/target/target_type.h
+++ b/src/target/target_type.h
@@ -297,6 +297,10 @@ struct target_type {
         */
        int (*gdb_fileio_end)(struct target *target, int retcode, int 
fileio_errno, bool ctrl_c);
 
+       /* parse target-specific GDB query commands
+        */
+       int (*gdb_query_custom)(struct target *target, const char *packet, char 
**response_p);
+
        /* do target profiling
         */
        int (*profiling)(struct target *target, uint32_t *samples,

--