On 3/7/20 1:04 AM, Lirong Yuan wrote:
This allows gdb to access the target’s auxiliary vector,
which can be helpful for telling system libraries important details
about the hardware, operating system, and process.
Signed-off-by: Lirong Yuan <yua...@google.com>
---
gdbstub.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
diff --git a/gdbstub.c b/gdbstub.c
index 22a2d630cd..c2865ea873 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -2105,6 +2105,12 @@ static void handle_query_supported(GdbCmdContext
*gdb_ctx, void *user_ctx)
pstrcat(gdb_ctx->str_buf, sizeof(gdb_ctx->str_buf),
";qXfer:features:read+");
}
+#ifdef CONFIG_USER_ONLY
+ if (gdb_ctx->s->c_cpu->opaque) {
+ pstrcat(gdb_ctx->str_buf, sizeof(gdb_ctx->str_buf),
+ ";qXfer:auxv:read+");
+ }
+#endif
if (gdb_ctx->num_params &&
strstr(gdb_ctx->params[0].data, "multiprocess+")) {
@@ -2166,6 +2172,42 @@ static void handle_query_xfer_features(GdbCmdContext
*gdb_ctx, void *user_ctx)
put_packet_binary(gdb_ctx->s, gdb_ctx->str_buf, len + 1, true);
}
+#ifdef CONFIG_USER_ONLY
+static void handle_query_xfer_auxv(GdbCmdContext *gdb_ctx, void *user_ctx)
+{
+ TaskState *ts;
+ unsigned long offset, len, saved_auxv, auxv_len;
+ const char *mem;
+
+ if (gdb_ctx->num_params < 2) {
+ put_packet(gdb_ctx->s, "E22");
+ return;
+ }
+
+ offset = gdb_ctx->params[0].val_ul;
+ len = gdb_ctx->params[1].val_ul;
+
+ ts = gdb_ctx->s->c_cpu->opaque;
+ saved_auxv = ts->info->saved_auxv;
+ auxv_len = ts->info->auxv_len;
Maybe check we are in range first?
if (offset + len > auxv_len) {
put_packet(gdb_ctx->s, "E22");
return;
}
+ mem = (const char *)(saved_auxv + offset);
+
+ if (len > (MAX_PACKET_LENGTH - 5) / 2) {
+ len = (MAX_PACKET_LENGTH - 5) / 2;
+ }
+
+ if (len < auxv_len - offset) {
+ gdb_ctx->str_buf[0] = 'm';
+ len = memtox(gdb_ctx->str_buf + 1, mem, len);
+ } else {
+ gdb_ctx->str_buf[0] = 'l';
+ len = memtox(gdb_ctx->str_buf + 1, mem, auxv_len - offset);
+ }
+
+ put_packet_binary(gdb_ctx->s, gdb_ctx->str_buf, len + 1, true);
+}
+#endif
+
static void handle_query_attached(GdbCmdContext *gdb_ctx, void *user_ctx)
{
put_packet(gdb_ctx->s, GDB_ATTACHED);
@@ -2271,6 +2313,14 @@ static GdbCmdParseEntry gdb_gen_query_table[] = {
.cmd_startswith = 1,
.schema = "s:l,l0"
},
+#ifdef CONFIG_USER_ONLY
+ {
+ .handler = handle_query_xfer_auxv,
+ .cmd = "Xfer:auxv:read:",
+ .cmd_startswith = 1,
+ .schema = "l,l0"
+ },
+#endif
{
.handler = handle_query_attached,
.cmd = "Attached:",