From 9ae5801d35b5228583dfcdb9c76cf2c6f4566215 Mon Sep 17 00:00:00 2001 From: Gustavo Romero Date: Sat, 9 Mar 2024 03:09:00 +0000 Subject: [PATCH] gdbstub: Add Xfer:siginfo:read stub MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add stub to handle Xfer:siginfo:read packet query that requests the machine's siginfo data. This is used when GDB user executes 'print $_siginfo' and when the machine stops due to a signal, for instance, on SIGSEGV. The information in siginfo allows GDB to determiner further details on the signal, like the fault address/insn when the SIGSEGV is caught. Signed-off-by: Gustavo Romero Message-Id: <20240309030901.1726211-5-gustavo.romero@linaro.org> Signed-off-by: Alex Bennée Reviewed-by: Richard Henderson --- gdbstub/gdbstub.c | 8 ++++++++ gdbstub/internals.h | 1 + gdbstub/user.c | 23 +++++++++++++++++++++++ 3 files changed, 32 insertions(+) diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c index 17efcae0d0..9c23d44baf 100644 --- a/gdbstub/gdbstub.c +++ b/gdbstub/gdbstub.c @@ -1664,6 +1664,8 @@ static void handle_query_supported(GArray *params, void *user_ctx) g_string_append(gdbserver_state.str_buf, ";qXfer:auxv:read+"); } g_string_append(gdbserver_state.str_buf, ";QCatchSyscalls+"); + + g_string_append(gdbserver_state.str_buf, ";qXfer:siginfo:read+"); #endif g_string_append(gdbserver_state.str_buf, ";qXfer:exec-file:read+"); #endif @@ -1818,6 +1820,12 @@ static const GdbCmdParseEntry gdb_gen_query_table[] = { .cmd_startswith = 1, .schema = "l,l0" }, + { + .handler = gdb_handle_query_xfer_siginfo, + .cmd = "Xfer:siginfo:read::", + .cmd_startswith = 1, + .schema = "l,l0" + }, #endif { .handler = gdb_handle_query_xfer_exec_file, diff --git a/gdbstub/internals.h b/gdbstub/internals.h index b472459838..e83b179920 100644 --- a/gdbstub/internals.h +++ b/gdbstub/internals.h @@ -190,6 +190,7 @@ typedef union GdbCmdVariant { void gdb_handle_query_rcmd(GArray *params, void *user_ctx); /* softmmu */ void gdb_handle_query_offsets(GArray *params, void *user_ctx); /* user */ void gdb_handle_query_xfer_auxv(GArray *params, void *user_ctx); /*user */ +void gdb_handle_query_xfer_siginfo(GArray *params, void *user_ctx); /*user */ void gdb_handle_v_file_open(GArray *params, void *user_ctx); /* user */ void gdb_handle_v_file_close(GArray *params, void *user_ctx); /* user */ void gdb_handle_v_file_pread(GArray *params, void *user_ctx); /* user */ diff --git a/gdbstub/user.c b/gdbstub/user.c index cf693bfbc4..2005f3312b 100644 --- a/gdbstub/user.c +++ b/gdbstub/user.c @@ -852,3 +852,26 @@ void gdb_handle_set_catch_syscalls(GArray *params, void *user_ctx) err: gdb_put_packet("E00"); } + +void gdb_handle_query_xfer_siginfo(GArray *params, void *user_ctx) +{ + unsigned long offset, len; + uint8_t *siginfo_offset; + + offset = get_param(params, 0)->val_ul; + len = get_param(params, 1)->val_ul; + + if (offset + len > gdbserver_user_state.siginfo_len) { + /* Invalid offset and/or requested length. */ + gdb_put_packet("E01"); + return; + } + + siginfo_offset = (uint8_t *)gdbserver_user_state.siginfo + offset; + + /* Reply */ + g_string_assign(gdbserver_state.str_buf, "l"); + gdb_memtox(gdbserver_state.str_buf, (const char *)siginfo_offset, len); + gdb_put_packet_binary(gdbserver_state.str_buf->str, + gdbserver_state.str_buf->len, true); +}