diff --git a/gdb/NEWS b/gdb/NEWS index 4dcc344b072..1b5e1e89534 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -182,6 +182,11 @@ binary-upload in qSupported reply stub doesn't report this feature supported, then GDB will not use the 'x' packet. +vFile:lstat + Return information about files on the remote system. Like + vFile:stat but if the filename is a symbolic link, return + information about the link itself, the file the link refers to. + * Changed remote packets qXfer:threads:read diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index c41aa89a3c4..a564307053e 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -24782,6 +24782,10 @@ future connections is shown. The available settings are: @tab @code{vFile:stat} @tab Host I/O +@item @code{hostio-lstat-packet} +@tab @code{vFile:lstat} +@tab Host I/O + @item @code{hostio-setfs-packet} @tab @code{vFile:setfs} @tab Host I/O @@ -46732,6 +46736,17 @@ and the return value is the size of this attachment in bytes. If an error occurs the return value is -1. The format of the returned binary attachment is as described in @ref{struct stat}. +@item vFile:lstat: @var{filename} +Get information about the file @var{filename} on the target as if from +an @samp{lstat} call. On success the information is returned as a +binary attachment and the return value is the size of this attachment +in bytes. If an error occurs the return value is -1. The format of +the returned binary attachment is as described in @ref{struct stat}. + +If @var{filename} is a symbolic link, then this packet returns +information about the link itself, not the file that the link refers +to, this is inline with the @samp{lstat} library call. + @item vFile:unlink: @var{filename} Delete the file at @var{filename} on the target. Return 0, or -1 if an error occurs. The @var{filename} is a string. diff --git a/gdb/remote.c b/gdb/remote.c index 92d428c63d0..8c3040f57ab 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -251,6 +251,7 @@ enum { PACKET_vFile_readlink, PACKET_vFile_fstat, PACKET_vFile_stat, + PACKET_vFile_lstat, PACKET_qXfer_auxv, PACKET_qXfer_features, PACKET_qXfer_exec_file, @@ -13242,14 +13243,14 @@ remote_target::fileio_lstat (struct inferior *inf, const char *filename, if (remote_hostio_set_filesystem (inf, remote_errno) != 0) return {}; - remote_buffer_add_string (&p, &left, "vFile:stat:"); + remote_buffer_add_string (&p, &left, "vFile:lstat:"); remote_buffer_add_bytes (&p, &left, (const gdb_byte *) filename, strlen (filename)); int attachment_len; const char *attachment; - int ret = remote_hostio_send_command (p - rs->buf.data (), PACKET_vFile_stat, + int ret = remote_hostio_send_command (p - rs->buf.data (), PACKET_vFile_lstat, remote_errno, &attachment, &attachment_len); @@ -16422,6 +16423,8 @@ Show the maximum size of the address (in bits) in a memory packet."), NULL, add_packet_config_cmd (PACKET_vFile_stat, "vFile:stat", "hostio-stat", 0); + add_packet_config_cmd (PACKET_vFile_lstat, "vFile:lstat", "hostio-lstat", 0); + add_packet_config_cmd (PACKET_vAttach, "vAttach", "attach", 0); add_packet_config_cmd (PACKET_vRun, "vRun", "run", 0); diff --git a/gdb/testsuite/gdb.server/build-id-seqno.exp b/gdb/testsuite/gdb.server/build-id-seqno.exp index a508a4454b7..8475cccfcc3 100644 --- a/gdb/testsuite/gdb.server/build-id-seqno.exp +++ b/gdb/testsuite/gdb.server/build-id-seqno.exp @@ -90,13 +90,13 @@ proc load_binfile_check_debug_is_found { debuginfo_file testname } { with_test_prefix "$testname" { with_timeout_factor 5 { # Probing for .build-id based debug files on remote - # targets uses the vFile:stat packet by default, though + # targets uses the vFile:lstat packet by default, though # there is a work around that avoids this which can be # used if GDB is connected to an older gdbserver without # 'stat' support. # # Check the work around works by disabling use of the - # vFile:stat packet. + # vFile:lstat packet. foreach_with_prefix stat_pkt {auto off} { clean_restart @@ -105,7 +105,7 @@ proc load_binfile_check_debug_is_found { debuginfo_file testname } { gdb_test_no_output "set sysroot target:" - gdb_test "set remote hostio-stat-packet $stat_pkt" + gdb_test "set remote hostio-lstat-packet $stat_pkt" # Make sure we're disconnected, in case we're testing with an # extended-remote board, therefore already connected. diff --git a/gdb/testsuite/gdb.server/fileio-packets.exp b/gdb/testsuite/gdb.server/fileio-packets.exp new file mode 100644 index 00000000000..d243e93c9e7 --- /dev/null +++ b/gdb/testsuite/gdb.server/fileio-packets.exp @@ -0,0 +1,60 @@ +# Copyright 2025 Free Software Foundation, Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# Test some remote file I/O. The associated Python script uses the +# Python API to create and send vFile:* packets to gdbserver to +# perform actions like 'stat'. The same action is then performed +# directly from Python (e.g. a 'stat' is performed), and the results, +# from gdbserver, and from the local syscall, are compared. + +load_lib gdb-python.exp +load_lib gdbserver-support.exp + +require allow_python_tests +require allow_gdbserver_tests +require {!is_remote host} +require {!is_remote target} + +standard_testfile + +clean_restart + +# Make sure we're disconnected, in case we're testing with an +# extended-remote board, therefore already connected. +gdb_test "disconnect" ".*" + +set pyfile [gdb_remote_download host ${srcdir}/${subdir}/${testfile}.py] +gdb_test_no_output "source $pyfile" "source the script" + +# Start gdbserver, but always in extended-remote mode, and then +# connect to it from GDB. +set res [gdbserver_start "--multi --once" ""] +set gdbserver_protocol "extended-remote" +set gdbserver_gdbport [lindex $res 1] +gdb_target_cmd $gdbserver_protocol $gdbserver_gdbport + +gdb_test_no_output "set python print-stack full" + +set test_file_1 [standard_output_file "test_file_1"] +remote_exec host "touch $test_file_1" + +set test_file_2 [standard_output_file "test_file_2"] +remote_exec host "ln -s $test_file_1 $test_file_2" + +gdb_test "python check_lstat(\"$test_file_1\")" "PASS" \ + "check remote lstat works on a normal file" + +gdb_test "python check_lstat(\"$test_file_2\")" "PASS" \ + "check remote lstat works on a symbolic link" diff --git a/gdb/testsuite/gdb.server/fileio-packets.py b/gdb/testsuite/gdb.server/fileio-packets.py new file mode 100644 index 00000000000..53fb49e8167 --- /dev/null +++ b/gdb/testsuite/gdb.server/fileio-packets.py @@ -0,0 +1,170 @@ +# Copyright (C) 2025 Free Software Foundation, Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +import os, stat + + +# Hex encode INPUT_STRING in the same way that GDB does. Each +# character in INPUT_STRING is expanded to its two digit hex +# representation in the returned string. +# +# Only ASCII characters may appear in INPUT_STRING, this is more +# restrictive than GDB, but is good enough for testing. +def hex_encode(input_string): + byte_string = input_string.encode("ascii") + hex_string = byte_string.hex() + return hex_string + + +# Binary remote data packets can contain some escaped bytes. Decode +# the packet now. +def unescape_remote_data(buf): + escaped = False + res = bytearray() + for b in buf: + if escaped: + res.append(b ^ 0x20) + escaped = False + elif b == ord("}"): + escaped = True + else: + res.append(b) + res = bytes(res) + return res + + +# Decode the results of a remote stat like command from BUF. Returns +# None if BUF is not a valid stat result (e.g. if it indicates an +# error, or the buffer is too short). If BUF is valid then the fields +# are decoded according to the GDB remote protocol and placed into a +# dictionary, this dictionary is then returned. +def decode_stat_reply(buf, byteorder="big"): + + buf = unescape_remote_data(buf) + + if ( + buf[0] != ord("F") + or buf[1] != ord("4") + or buf[2] != ord("0") + or buf[3] != ord(";") + or len(buf) != 68 + ): + l = len(buf) + print(f"decode_stat_reply failed: {buf}\t(length = {l})") + return None + + # Discard the 'F40;' prefix. The rest is the 64 bytes of data to + # be decoded. + buf = buf[4:] + + st_dev = int.from_bytes(buf[0:4], byteorder=byteorder) + st_ino = int.from_bytes(buf[4:8], byteorder=byteorder) + st_mode = int.from_bytes(buf[8:12], byteorder=byteorder) + st_nlink = int.from_bytes(buf[12:16], byteorder=byteorder) + st_uid = int.from_bytes(buf[16:20], byteorder=byteorder) + st_gid = int.from_bytes(buf[20:24], byteorder=byteorder) + st_rdev = int.from_bytes(buf[24:28], byteorder=byteorder) + st_size = int.from_bytes(buf[28:36], byteorder=byteorder) + st_blksize = int.from_bytes(buf[36:44], byteorder=byteorder) + st_blocks = int.from_bytes(buf[44:52], byteorder=byteorder) + st_atime = int.from_bytes(buf[52:56], byteorder=byteorder) + st_mtime = int.from_bytes(buf[56:60], byteorder=byteorder) + st_ctime = int.from_bytes(buf[60:64], byteorder=byteorder) + + return { + "st_dev": st_dev, + "st_ino": st_ino, + "st_mode": st_mode, + "st_nlink": st_nlink, + "st_uid": st_uid, + "st_gid": st_gid, + "st_rdev": st_rdev, + "st_size": st_size, + "st_blksize": st_blksize, + "st_blocks": st_blocks, + "st_atime": st_atime, + "st_mtime": st_mtime, + "st_ctime": st_ctime, + } + + +# Perform an lstat of remote file FILENAME, and create a dictionary of +# the results, the keys are the fields of the stat structure. +def remote_lstat(filename): + conn = gdb.selected_inferior().connection + if not isinstance(conn, gdb.RemoteTargetConnection): + raise gdb.GdbError("connection is the wrong type") + + filename_hex = hex_encode(filename) + reply = conn.send_packet("vFile:lstat:%s" % filename_hex) + + stat = decode_stat_reply(reply) + return stat + + +# Convert a stat_result object to a dictionary that should match the +# dictionary built from the remote protocol reply. +def stat_result_to_dict(res): + # GDB doesn't support the S_IFLNK flag for the remote protocol, so + # clear that flag in the local results. + if stat.S_ISLNK(res.st_mode): + st_mode = stat.S_IMODE(res.st_mode) + else: + st_mode = res.st_mode + + # GDB returns an integer for these fields, while Python returns a + # floating point value. Convert back to an integer to match GDB. + st_atime = int(res.st_atime) + st_mtime = int(res.st_mtime) + st_ctime = int(res.st_ctime) + + return { + "st_dev": res.st_dev, + "st_ino": res.st_ino, + "st_mode": st_mode, + "st_nlink": res.st_nlink, + "st_uid": res.st_uid, + "st_gid": res.st_gid, + "st_rdev": res.st_rdev, + "st_size": res.st_size, + "st_blksize": res.st_blksize, + "st_blocks": res.st_blocks, + "st_atime": st_atime, + "st_mtime": st_mtime, + "st_ctime": st_ctime, + } + + +# Perform an lstat of local file FILENAME, and create a dictionary of +# the results, the keys are the fields of the stat structure. +def local_lstat(filename): + res = os.lstat(filename) + return stat_result_to_dict(res) + + +# Perform a remote lstat using GDB, and a local lstat using os.lstat. +# Compare the results to check they are the same. +# +# For this test to work correctly, gdbserver, and GDB (where this +# Python script is running), must see the same filesystem. +def check_lstat(filename): + s1 = remote_lstat(filename) + s2 = local_lstat(filename) + + print(f"s1 = {s1}") + print(f"s2 = {s2}") + + assert s1 == s2 + print("PASS") diff --git a/gdbserver/hostio.cc b/gdbserver/hostio.cc index 17b6179d8ca..05f2c4e0b33 100644 --- a/gdbserver/hostio.cc +++ b/gdbserver/hostio.cc @@ -522,6 +522,42 @@ handle_stat (char *own_buf, int *new_packet_len) write_enn (own_buf); } +static void +handle_lstat (char *own_buf, int *new_packet_len) +{ + int bytes_sent; + char *p; + struct stat st; + struct fio_stat fst; + char filename[HOSTIO_PATH_MAX]; + + p = own_buf + strlen ("vFile:lstat:"); + + if (require_filename (&p, filename) + || require_end (p)) + { + hostio_packet_error (own_buf); + return; + } + + if (lstat (filename, &st) == -1) + { + hostio_error (own_buf); + return; + } + + host_to_fileio_stat (&st, &fst); + + bytes_sent = hostio_reply_with_data (own_buf, + (char *) &fst, sizeof (fst), + new_packet_len); + + /* If the response does not fit into a single packet, do not attempt + to return a partial response, but simply fail. */ + if (bytes_sent < sizeof (fst)) + write_enn (own_buf); +} + static void handle_close (char *own_buf) { @@ -641,6 +677,8 @@ handle_vFile (char *own_buf, int packet_len, int *new_packet_len) handle_fstat (own_buf, new_packet_len); else if (startswith (own_buf, "vFile:stat:")) handle_stat (own_buf, new_packet_len); + else if (startswith (own_buf, "vFile:lstat:")) + handle_lstat (own_buf, new_packet_len); else if (startswith (own_buf, "vFile:close:")) handle_close (own_buf); else if (startswith (own_buf, "vFile:unlink:"))