On Fri, Mar 6, 2020 at 5:01 PM Lirong Yuan <yua...@google.com> 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 | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 55 insertions(+)
>
> diff --git a/gdbstub.c b/gdbstub.c
> index 22a2d630cd..a946af7007 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 +2172,47 @@ 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;
> + mem = (const char *)(saved_auxv + offset);
> +
> + if (offset >= auxv_len) {
> + put_packet(gdb_ctx->s, "E22");
> + return;
> + }
> +
> + 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 +2318,14 @@ 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:",
> --
> 2.25.1.481.gfbce0eb801-goog
>
>
Friendly ping~
Link to the patchwork page:
http://patchwork.ozlabs.org/patch/1250727/
