Hi Andrew, Ping. Eli has given Reviewed-By on the documentation, with his comments incorporated. The remote protocol side still needs your review. Thanks, Abhay On 16/09/26 18:52, Abhay Kandpal wrote: > Hi Andrew, > Ping. Let me know if the vFile-only scope looks right to you. > Thanks, > Abhay > > > On 04/09/26 14:02, Abhay Kandpal wrote: >> The struct sent by the vFile:fstat, vFile:stat and vFile:lstat packets >> declares st_dev, st_ino, st_nlink, st_rdev and the three timestamps as >> 4-byte fields, while the corresponding struct stat members are 8 bytes >> on a 64-bit host. The values are silently truncated. >> >> This is not visible on a filesystem whose inode numbers stay below >> 2^32, but it is on a large one. On an 86 TB xfs volume, >> gdb.server/fileio-packets.exp fails because the inode reported by >> vFile:lstat does not match the one reported locally: >> >> remote = {..., 'st_ino': 2161233200, ...} >> local = {..., 'st_ino': 122420317488, ...} >> >> The field widths cannot simply be changed, as that would alter the wire >> layout and break communication between different versions of GDB and >> gdbserver. Add a new 'stat64' qSupported feature instead. When both >> sides report it, the vFile stat packets return struct fio_stat_wide, in >> which the six too-narrow fields are 8 bytes; otherwise the existing >> struct fio_stat is used, exactly as before. >> >> Internally both GDB and gdbserver now work with the wide struct, and >> the conversion happens at the wire boundary: gdbserver narrows the >> result before sending it if the feature was not negotiated, and GDB >> selects the unpacker by the length of the reply. Narrowing a value >> which does not fit now produces a warning rather than truncating >> silently. >> >> Only the vFile packets are changed. The F-packet file-i/o protocol >> uses the same struct, but writes it directly into inferior memory, >> where the target reads it as the layout documented in the manual under >> "struct stat"; that layout is left alone. >> >> While here, drop a duplicate include of gdbsupport/fileio.h from >> gdbserver/hostio.cc. >> >> Tested on powerpc64le-linux; gdb.server/fileio-packets.exp now passes on >> a filesystem with inode numbers above 2^32 and continues to pass on one >> without, with no unexpected failures in the full testsuite. >> >> gdb/ >> * NEWS: Mention the stat64 feature. >> * doc/gdb.texinfo (General Query Packets): Document the stat64 >> feature. >> (Host I/O Packets): Mention the wide reply format. >> (struct stat64): New node. >> * remote-fileio.c (remote_fileio_to_host_ulong8): New function. >> (remote_fileio_wide_to_host_stat): New function. >> * remote-fileio.h (remote_fileio_wide_to_host_stat): Declare. >> * remote.c (PACKET_stat64_feature): New enum value. >> (remote_features::stat64_feature): New method. >> (remote_protocol_features): Add stat64. >> (remote_target::remote_query_supported): Send stat64+. >> (fileio_process_fstat_and_lstat_reply): Handle both formats. >> (INIT_GDB_FILE): Add the stat64-feature packet command. >> * testsuite/gdb.server/fileio-packets.py (decode_stat_reply): >> Handle both the narrow and wide reply formats. >> >> gdbserver/ >> * hostio.cc (handle_fstat, handle_stat, handle_lstat): Send the >> wide struct when the feature is negotiated. >> * server.cc (handle_query): Handle and report stat64. >> * server.h (client_state::stat64_feature): New member. >> >> gdbsupport/ >> * fileio.cc (host_to_fileio_stat_wide): New function. >> (narrow_field, fileio_stat_wide_to_narrow): New functions. >> * fileio.h (struct fio_stat_wide): New struct. >> (bigendian_to_host): New function. >> (host_to_fileio_stat_wide, fileio_stat_wide_to_narrow): Declare. >> >> Bug:https://sourceware.org/bugzilla/show_bug.cgi?id=34567 >> Reviewed-By: Eli Zaretskii >> --- >> This patch is reg tested. >> >> gdb/NEWS | 13 +++ >> gdb/doc/gdb.texinfo | 50 ++++++++++ >> gdb/remote-fileio.c | 35 ++++++- >> gdb/remote-fileio.h | 4 + >> gdb/remote.c | 36 +++++-- >> gdb/testsuite/gdb.server/fileio-packets.py | 59 +++++++----- >> gdbserver/hostio.cc | 106 +++++++++++++++------ >> gdbserver/server.cc | 4 +- >> gdbserver/server.h | 5 + >> gdbsupport/fileio.cc | 70 ++++++++++++++ >> gdbsupport/fileio.h | 54 ++++++++++- >> 11 files changed, 370 insertions(+), 66 deletions(-) >> >> diff --git a/gdb/NEWS b/gdb/NEWS >> index 222f38e3d52..7c1a09752a9 100644 >> --- a/gdb/NEWS >> +++ b/gdb/NEWS >> @@ -3,6 +3,19 @@ >> >> *** Changes since GDB 18 >> >> +* Changed remote packets >> + >> +stat64 in qSupported >> + >> + The new stat64 feature within the qSupported packet allows GDB and >> + the stub to agree on a wider form of the stat structure returned by >> + the vFile:fstat, vFile:stat and vFile:lstat packets, in which st_dev, >> + st_ino, st_nlink, st_rdev and the three timestamps are 8 bytes rather >> + than 4. The wider form is used only when both sides report the >> + feature; otherwise the existing format is used and values which do >> + not fit are truncated as before. Note that the narrow form reads >> + timestamps as unsigned, so it overflows in 2106 rather than 2038. >> + >> *** Changes in GDB 18 >> >> * Support for the Common Trace Format (CTF) has been removed. GDB now >> diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo >> index 0030698dcee..355153212f0 100644 >> --- a/gdb/doc/gdb.texinfo >> +++ b/gdb/doc/gdb.texinfo >> @@ -46112,6 +46112,11 @@ inspected, if @samp{qIsAddressTagged} (@pxref{qIsAddressTagged}) packet >> is not supported by the stub. Access to the @file{/proc/@var{pid}/smaps} >> file is done via @samp{vFile} requests. >> >> +@item stat64 >> +The remote stub supports the wider form of the stat structure returned >> +by the @samp{vFile:fstat}, @samp{vFile:stat} and @samp{vFile:lstat} >> +packets (@pxref{struct stat64}). >> + >> @item error-message >> The remote stub supports replying with an error in a >> @samp{E.@var{errtext}} (@xref{textual error reply}) format from the >> @@ -47358,6 +47363,9 @@ 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 both @value{GDBN} and the stub report the @samp{stat64} feature in >> +the @samp{qSupported} exchange, the wider format is used instead >> +(@pxref{struct stat64}). >> >> @item vFile:stat: @var{filename} >> Get information about the file @var{filename} on the target as if from >> @@ -47365,6 +47373,9 @@ a @samp{stat} 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 both @value{GDBN} and the stub report the @samp{stat64} feature in >> +the @samp{qSupported} exchange, the wider format is used instead >> +(@pxref{struct stat64}). >> >> If @var{filename} is a symbolic link, then the information returned is >> about the file the link refers to, this is inline with the @samp{stat} >> @@ -47376,6 +47387,9 @@ 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 both @value{GDBN} and the stub report the @samp{stat64} feature in >> +the @samp{qSupported} exchange, the wider format is used instead >> +(@pxref{struct stat64}). >> >> This packet is identical to @samp{vFile:stat}, except if >> @var{filename} is a symbolic link, then this packet returns >> @@ -48570,6 +48584,7 @@ protocol. >> * Pointer Values:: >> * Memory Transfer:: >> * struct stat:: >> +* struct stat64:: >> * struct timeval:: >> @end menu >> >> @@ -48696,6 +48711,41 @@ Note that due to size differences between the host, target, and protocol >> representations of @code{struct stat} members, these members could eventually >> get truncated on the target. >> >> +@node struct stat64 >> +@unnumberedsubsubsec struct stat64 >> +@cindex struct stat64, in file-i/o protocol >> + >> +When the @samp{stat64} feature has been negotiated, the buffer returned >> +by the @samp{vFile:fstat}, @samp{vFile:stat} and @samp{vFile:lstat} >> +packets uses the following representation instead: >> + >> +@smallexample >> +struct stat64 @{ >> + uint64_t st_dev; /* device */ >> + uint64_t st_ino; /* inode */ >> + mode_t st_mode; /* protection */ >> + uint64_t st_nlink; /* number of hard links */ >> + unsigned int st_uid; /* user ID of owner */ >> + unsigned int st_gid; /* group ID of owner */ >> + uint64_t st_rdev; /* device type (if inode device) */ >> + uint64_t st_size; /* total size, in bytes */ >> + uint64_t st_blksize; /* blocksize for filesystem I/O */ >> + uint64_t st_blocks; /* number of blocks allocated */ >> + uint64_t st_atime; /* time of last access */ >> + uint64_t st_mtime; /* time of last modification */ >> + uint64_t st_ctime; /* time of last change */ >> +@}; >> +@end smallexample >> + >> +This structure is of size 92 bytes. The fields have the same meanings >> +as in the narrow form (@pxref{struct stat}), but @code{st_dev}, >> +@code{st_ino}, @code{st_nlink}, @code{st_rdev} and the three timestamps >> +are wide enough to hold the values found on a 64-bit host without >> +truncation. >> + >> +This representation is only used by the @samp{vFile} packets; the >> +File-I/O protocol always uses the narrow form (@pxref{struct stat}). >> + >> @node struct timeval >> @unnumberedsubsubsec struct timeval >> @cindex struct timeval, in file-i/o protocol >> diff --git a/gdb/remote-fileio.c b/gdb/remote-fileio.c >> index a151161371d..76deb80d10a 100644 >> --- a/gdb/remote-fileio.c >> +++ b/gdb/remote-fileio.c >> @@ -1220,7 +1220,40 @@ remote_fileio_to_host_stat (struct fio_stat *fst, struct stat *st) >> st->st_mtime = remote_fileio_to_host_time (fst->fst_mtime); >> st->st_ctime = remote_fileio_to_host_time (fst->fst_ctime); >> } >> - >> + >> +/* Unpack an 8-byte protocol field. */ >> + >> +static ULONGEST >> +remote_fileio_to_host_ulong8 (const char *fnum) >> +{ >> + return extract_unsigned_integer ((const gdb_byte *) fnum, 8, >> + BFD_ENDIAN_BIG); >> +} >> + >> +/* See remote-fileio.h. */ >> + >> +void >> +remote_fileio_wide_to_host_stat (struct fio_stat_wide *fst, struct stat *st) >> +{ >> + memset (st, 0, sizeof (struct stat)); >> + st->st_dev = remote_fileio_to_host_ulong8 (fst->fst_dev); >> + st->st_ino = remote_fileio_to_host_ulong8 (fst->fst_ino); >> + st->st_mode = remote_fileio_to_host_mode (fst->fst_mode); >> + st->st_nlink = remote_fileio_to_host_ulong8 (fst->fst_nlink); >> + st->st_uid = remote_fileio_to_host_uint (fst->fst_uid); >> + st->st_gid = remote_fileio_to_host_uint (fst->fst_gid); >> + st->st_rdev = remote_fileio_to_host_ulong8 (fst->fst_rdev); >> + st->st_size = remote_fileio_to_host_ulong8 (fst->fst_size); >> +#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE >> + st->st_blksize = remote_fileio_to_host_ulong8 (fst->fst_blksize); >> +#endif >> +#if HAVE_STRUCT_STAT_ST_BLOCKS >> + st->st_blocks = remote_fileio_to_host_ulong8 (fst->fst_blocks); >> +#endif >> + st->st_atime = remote_fileio_to_host_ulong8 (fst->fst_atime); >> + st->st_mtime = remote_fileio_to_host_ulong8 (fst->fst_mtime); >> + st->st_ctime = remote_fileio_to_host_ulong8 (fst->fst_ctime); >> +} >> >> static void >> set_system_call_allowed (const char *args, int from_tty) >> diff --git a/gdb/remote-fileio.h b/gdb/remote-fileio.h >> index d01b3df92ca..95fb042fc9d 100644 >> --- a/gdb/remote-fileio.h >> +++ b/gdb/remote-fileio.h >> @@ -44,4 +44,8 @@ extern void initialize_remote_fileio ( >> extern void remote_fileio_to_host_stat (struct fio_stat *fst, >> struct stat *st); >> >> +/* Unpack a struct fio_stat_wide. */ >> +extern void remote_fileio_wide_to_host_stat (struct fio_stat_wide *fst, >> + struct stat *st); >> + >> #endif /* GDB_REMOTE_FILEIO_H */ >> diff --git a/gdb/remote.c b/gdb/remote.c >> index 76cf6b5234f..03cb8a074b7 100644 >> --- a/gdb/remote.c >> +++ b/gdb/remote.c >> @@ -389,6 +389,8 @@ enum { >> packets and the tag violation stop replies. */ >> PACKET_memory_tagging_feature, >> >> + PACKET_stat64_feature, >> + >> /* Support for the qIsAddressTagged packet. */ >> PACKET_qIsAddressTagged, >> >> @@ -844,6 +846,9 @@ struct remote_features >> bool remote_memory_tagging_p () const >> { return packet_support (PACKET_memory_tagging_feature) == PACKET_ENABLE; } >> >> + bool stat64_feature () const >> + { return packet_support (PACKET_stat64_feature) == PACKET_ENABLE; } >> + >> /* Returns true if there is support for sending vRun inferior arguments >> as a single string. */ >> bool remote_vrun_single_arg_p () const >> @@ -6199,6 +6204,8 @@ static const struct protocol_feature remote_protocol_features[] = { >> { "no-resumed", PACKET_DISABLE, remote_supported_packet, PACKET_no_resumed }, >> { "memory-tagging", PACKET_DISABLE, remote_supported_packet, >> PACKET_memory_tagging_feature }, >> + { "stat64", PACKET_DISABLE, remote_supported_packet, >> + PACKET_stat64_feature }, >> { "error-message", PACKET_ENABLE, remote_supported_packet, >> PACKET_accept_error_message }, >> { "binary-upload", PACKET_DISABLE, remote_supported_packet, PACKET_x }, >> @@ -6309,6 +6316,10 @@ remote_target::remote_query_supported () >> != AUTO_BOOLEAN_FALSE) >> remote_query_supported_append (&q, "QThreadOptions+"); >> >> + if (m_features.packet_set_cmd_state (PACKET_stat64_feature) >> + != AUTO_BOOLEAN_FALSE) >> + remote_query_supported_append (&q, "stat64+"); >> + >> if (m_features.packet_set_cmd_state (PACKET_no_resumed) >> != AUTO_BOOLEAN_FALSE) >> remote_query_supported_append (&q, "no-resumed+"); @@ -13663,29 +13674,35 @@ remote_target::fileio_readlink (struct >> inferior *inf, const char *filename, remote syscall reply. >> EXPECTED_LEN is the length returned from the fstat or stat call, this >> the length of the returned data (in ATTACHMENT) once it has been >> decoded. The fstat/stat result (from the ATTACHMENT - data) is to be >> placed in ST. */ + data) is to be placed in ST. + The reply holds >> either a struct fio_stat or, if the stat64 feature was + negotiated, >> the wider struct fio_stat_wide; the two are distinguished + by their >> length. */ static int fileio_process_fstat_and_lstat_reply (const >> char *attachment, int attachment_len, int expected_len, struct stat >> *st) { - struct fio_stat fst; + gdb_byte buf[sizeof (struct >> fio_stat_wide)]; int read_len = remote_unescape_input ((gdb_byte *) >> attachment, attachment_len, - (gdb_byte *) &fst, sizeof (fst)); + >> buf, sizeof (buf)); if (read_len != expected_len) error (_("vFile:fstat returned %d, but %d bytes."), >> expected_len, read_len); >> >> - if (read_len != sizeof (fst)) >> - error (_("vFile:fstat returned %d bytes, but expecting %d."), >> - read_len, (int) sizeof (fst)); >> - >> - remote_fileio_to_host_stat (&fst, st); >> + if (read_len == sizeof (struct fio_stat_wide)) >> + remote_fileio_wide_to_host_stat ((struct fio_stat_wide *) buf, st); >> + else if (read_len == sizeof (struct fio_stat)) >> + remote_fileio_to_host_stat ((struct fio_stat *) buf, st); >> + else >> + error (_("vFile:fstat returned %d bytes, but expecting %d or %d."), + read_len, (int) sizeof (struct fio_stat), + (int) sizeof >> (struct fio_stat_wide)); return 0; } @@ -17039,6 +17056,9 @@ Show the >> maximum size of the address (in bits) in a memory packet."), NULL, >> add_packet_config_cmd (PACKET_memory_tagging_feature, >> "memory-tagging-feature", "memory-tagging-feature", 0); >> >> + add_packet_config_cmd (PACKET_stat64_feature, >> + "stat64-feature", "stat64-feature", 0); >> + >> add_packet_config_cmd (PACKET_qIsAddressTagged, >> "qIsAddressTagged", "memory-tagging-address-check", 0); >> >> diff --git a/gdb/testsuite/gdb.server/fileio-packets.py b/gdb/testsuite/gdb.server/fileio-packets.py >> index 54ae56fa68a..2d06edcdbf7 100644 >> --- a/gdb/testsuite/gdb.server/fileio-packets.py >> +++ b/gdb/testsuite/gdb.server/fileio-packets.py >> @@ -57,33 +57,48 @@ 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 >> - ): >> + if buf[0:4] == b"F40;" and len(buf) == 68: >> + wide = False >> + elif buf[0:4] == b"F5c;" and len(buf) == 96: >> + wide = True >> + else: >> print(f"decode_stat_reply failed: {buf}\t(length = {len(buf)})") >> return None >> >> - # Discard the 'F40;' prefix. The rest is the 64 bytes of data to >> - # be decoded. >> + # Discard the 'FNN;' prefix. >> 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) >> + def field(off, size): >> + return int.from_bytes(buf[off : off + size], byteorder=byteorder) >> + >> + if wide: >> + st_dev = field(0, 8) >> + st_ino = field(8, 8) >> + st_mode = field(16, 4) >> + st_nlink = field(20, 8) >> + st_uid = field(28, 4) >> + st_gid = field(32, 4) >> + st_rdev = field(36, 8) >> + st_size = field(44, 8) >> + st_blksize = field(52, 8) >> + st_blocks = field(60, 8) >> + st_atime = field(68, 8) >> + st_mtime = field(76, 8) >> + st_ctime = field(84, 8) >> + else: >> + st_dev = field(0, 4) >> + st_ino = field(4, 4) >> + st_mode = field(8, 4) >> + st_nlink = field(12, 4) >> + st_uid = field(16, 4) >> + st_gid = field(20, 4) >> + st_rdev = field(24, 4) >> + st_size = field(28, 8) >> + st_blksize = field(36, 8) >> + st_blocks = field(44, 8) >> + st_atime = field(52, 4) >> + st_mtime = field(56, 4) >> + st_ctime = field(60, 4) >> >> return { >> "st_dev": st_dev, >> diff --git a/gdbserver/hostio.cc b/gdbserver/hostio.cc >> index b9ca27c2ff4..34def5d22da 100644 >> --- a/gdbserver/hostio.cc >> +++ b/gdbserver/hostio.cc >> @@ -26,7 +26,6 @@ >> #include >> #include >> #include >> -#include "gdbsupport/fileio.h" >> >> struct fd_list >> { >> @@ -465,7 +464,7 @@ handle_fstat (char *own_buf, int *new_packet_len) >> int fd, bytes_sent; >> char *p; >> struct stat st; >> - struct fio_stat fst; >> + client_state &cs = get_client_state (); >> >> p = own_buf + strlen ("vFile:fstat:"); >> >> @@ -483,16 +482,31 @@ handle_fstat (char *own_buf, int *new_packet_len) >> return; >> } >> >> - host_to_fileio_stat (&st, &fst); >> - >> - bytes_sent = hostio_reply_with_data (own_buf, >> - (char *) &fst, sizeof (fst), >> - new_packet_len); >> + struct fio_stat_wide wide; >> + host_to_fileio_stat_wide (&st, &wide); >> >> - /* 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); >> + /* Send the wide form if GDB understands it, otherwise narrow the >> + result first. */ >> + if (cs.stat64_feature) >> + { >> + bytes_sent = hostio_reply_with_data (own_buf, (char *) &wide, >> + sizeof (wide), 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 (wide)) >> + write_enn (own_buf); >> + } >> + else >> + { >> + struct fio_stat narrow; >> + fileio_stat_wide_to_narrow (&wide, &narrow); >> + bytes_sent = hostio_reply_with_data (own_buf, (char *) &narrow, >> + sizeof (narrow), 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 (narrow)) >> + write_enn (own_buf); >> + } >> } >> >> static void >> @@ -501,8 +515,8 @@ handle_stat (char *own_buf, int *new_packet_len) >> int bytes_sent; >> char *p; >> struct stat st; >> - struct fio_stat fst; >> char filename[HOSTIO_PATH_MAX]; >> + client_state &cs = get_client_state (); >> >> p = own_buf + strlen ("vFile:stat:"); >> >> @@ -519,16 +533,31 @@ handle_stat (char *own_buf, int *new_packet_len) >> return; >> } >> >> - host_to_fileio_stat (&st, &fst); >> - >> - bytes_sent = hostio_reply_with_data (own_buf, >> - (char *) &fst, sizeof (fst), >> - new_packet_len); >> + struct fio_stat_wide wide; >> + host_to_fileio_stat_wide (&st, &wide); >> >> - /* 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); >> + /* Send the wide form if GDB understands it, otherwise narrow the >> + result first. */ >> + if (cs.stat64_feature) >> + { >> + bytes_sent = hostio_reply_with_data (own_buf, (char *) &wide, >> + sizeof (wide), 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 (wide)) >> + write_enn (own_buf); >> + } >> + else >> + { >> + struct fio_stat narrow; >> + fileio_stat_wide_to_narrow (&wide, &narrow); >> + bytes_sent = hostio_reply_with_data (own_buf, (char *) &narrow, >> + sizeof (narrow), 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 (narrow)) >> + write_enn (own_buf); >> + } >> } >> >> static void >> @@ -537,8 +566,8 @@ handle_lstat (char *own_buf, int *new_packet_len) >> int ret, bytes_sent; >> char *p; >> struct stat st; >> - struct fio_stat fst; >> char filename[HOSTIO_PATH_MAX]; >> + client_state &cs = get_client_state (); >> >> p = own_buf + strlen ("vFile:lstat:"); >> >> @@ -560,16 +589,31 @@ handle_lstat (char *own_buf, int *new_packet_len) >> return; >> } >> >> - host_to_fileio_stat (&st, &fst); >> - >> - bytes_sent = hostio_reply_with_data (own_buf, >> - (char *) &fst, sizeof (fst), >> - new_packet_len); >> + struct fio_stat_wide wide; >> + host_to_fileio_stat_wide (&st, &wide); >> >> - /* 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); >> + /* Send the wide form if GDB understands it, otherwise narrow the >> + result first. */ >> + if (cs.stat64_feature) >> + { >> + bytes_sent = hostio_reply_with_data (own_buf, (char *) &wide, >> + sizeof (wide), 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 (wide)) >> + write_enn (own_buf); >> + } >> + else >> + { >> + struct fio_stat narrow; >> + fileio_stat_wide_to_narrow (&wide, &narrow); >> + bytes_sent = hostio_reply_with_data (own_buf, (char *) &narrow, >> + sizeof (narrow), 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 (narrow)) >> + write_enn (own_buf); >> + } >> } >> >> static void >> diff --git a/gdbserver/server.cc b/gdbserver/server.cc >> index a208e24d09f..dfa24617847 100644 >> --- a/gdbserver/server.cc >> +++ b/gdbserver/server.cc >> @@ -2746,6 +2746,8 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p) >> cs.single_inferior_argument = true; >> else if (feature == "multi-wp-addr+") >> cs.multiple_wp_addr_feature = true; >> + else if (feature == "stat64+") >> + cs.stat64_feature = true; >> else >> { >> /* Move the unknown features all together. */ >> @@ -2762,7 +2764,7 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p) >> "PacketSize=%x;QPassSignals+;QProgramSignals+;" >> "QStartupWithShell+;QEnvironmentHexEncoded+;" >> "QEnvironmentReset+;QEnvironmentUnset+;" >> - "QSetWorkingDir+;binary-upload+", >> + "QSetWorkingDir+;binary-upload+;stat64+", PBUFSIZ - 1); if (target_supports_catch_syscall ()) diff --git >> a/gdbserver/server.h b/gdbserver/server.h index >> bbba3650de7..cf811f228fa 100644 --- a/gdbserver/server.h +++ >> b/gdbserver/server.h @@ -192,6 +192,11 @@ struct client_state /* If >> true, memory tagging features are supported. */ bool >> memory_tagging_feature = false; + /* True if GDB supports the wide >> form of struct stat in the vFile + fstat, stat and lstat replies. >> When false, gdbserver narrows the + result to struct fio_stat before >> sending it. */ + bool stat64_feature = false; + /* If true then >> E.errtext style errors are supported everywhere, including for the >> qRcmd and m packet. When false E.errtext errors are not supported >> with qRcmd and m packets, but are still supported diff --git >> a/gdbsupport/fileio.cc b/gdbsupport/fileio.cc index >> 6d2ffb14544..bab2c4c8efe 100644 --- a/gdbsupport/fileio.cc +++ >> b/gdbsupport/fileio.cc @@ -20,6 +20,7 @@ #include "fileio.h" >> #include >> #include >> +#include "gdbsupport/errors.h" >> >> /* See fileio.h. */ >> >> @@ -305,3 +306,72 @@ host_to_fileio_stat (struct stat *st, struct fio_stat *fst) >> host_to_fileio_time (st->st_mtime, fst->fst_mtime); >> host_to_fileio_time (st->st_ctime, fst->fst_ctime); >> } >> + >> +/* See fileio.h. */ >> + >> +void >> +host_to_fileio_stat_wide (struct stat *st, struct fio_stat_wide *fst) >> +{ >> + LONGEST blksize; >> + >> + host_to_bigendian ((LONGEST) st->st_dev, (char *) fst->fst_dev, 8); >> + host_to_bigendian ((LONGEST) st->st_ino, (char *) fst->fst_ino, 8); >> + host_to_fileio_mode (st->st_mode, fst->fst_mode); >> + host_to_bigendian ((LONGEST) st->st_nlink, (char *) fst->fst_nlink, 8); >> + host_to_fileio_uint ((long) st->st_uid, fst->fst_uid); >> + host_to_fileio_uint ((long) st->st_gid, fst->fst_gid); >> + host_to_bigendian ((LONGEST) st->st_rdev, (char *) fst->fst_rdev, 8); >> + host_to_bigendian ((LONGEST) st->st_size, (char *) fst->fst_size, 8); >> +#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE >> + blksize = st->st_blksize; >> +#else >> + blksize = 512; >> +#endif >> + host_to_bigendian (blksize, (char *) fst->fst_blksize, 8); >> +#if HAVE_STRUCT_STAT_ST_BLOCKS >> + host_to_bigendian ((LONGEST) st->st_blocks, (char *) fst->fst_blocks, 8); >> +#else >> + host_to_bigendian (((LONGEST) st->st_size + blksize - 1) / blksize, >> + (char *) fst->fst_blocks, 8); >> +#endif >> + host_to_bigendian ((LONGEST) st->st_atime, (char *) fst->fst_atime, 8); >> + host_to_bigendian ((LONGEST) st->st_mtime, (char *) fst->fst_mtime, 8); >> + host_to_bigendian ((LONGEST) st->st_ctime, (char *) fst->fst_ctime, 8); >> +} >> + >> +/* Copy the 8-byte value in FROM into the 4-byte field TO, warning if >> + the value does not fit. WHAT names the field, for the warning. */ >> + >> +static void >> +narrow_field (const char *from, char *to, const char *what) >> +{ >> + ULONGEST num = bigendian_to_host (from, 8); >> + >> + if (num != (ULONGEST) (uint32_t) num) >> + warning (_("file-i/o: %s value %s does not fit in 32 bits; " >> + "the value seen by the peer will be truncated"), >> + what, pulongest (num)); >> + >> + host_to_bigendian ((LONGEST) num, to, 4); >> +} >> + >> +/* See fileio.h. */ >> + >> +void >> +fileio_stat_wide_to_narrow (const struct fio_stat_wide *wide, >> + struct fio_stat *narrow) >> +{ >> + narrow_field (wide->fst_dev, narrow->fst_dev, "st_dev"); >> + narrow_field (wide->fst_ino, narrow->fst_ino, "st_ino"); >> + memcpy (narrow->fst_mode, wide->fst_mode, 4); >> + narrow_field (wide->fst_nlink, narrow->fst_nlink, "st_nlink"); >> + memcpy (narrow->fst_uid, wide->fst_uid, 4); >> + memcpy (narrow->fst_gid, wide->fst_gid, 4); >> + narrow_field (wide->fst_rdev, narrow->fst_rdev, "st_rdev"); >> + memcpy (narrow->fst_size, wide->fst_size, 8); >> + memcpy (narrow->fst_blksize, wide->fst_blksize, 8); >> + memcpy (narrow->fst_blocks, wide->fst_blocks, 8); >> + narrow_field (wide->fst_atime, narrow->fst_atime, "st_atime"); >> + narrow_field (wide->fst_mtime, narrow->fst_mtime, "st_mtime"); >> + narrow_field (wide->fst_ctime, narrow->fst_ctime, "st_ctime"); >> +} >> diff --git a/gdbsupport/fileio.h b/gdbsupport/fileio.h >> index c2592cf8c15..fa5de54dd40 100644 >> --- a/gdbsupport/fileio.h >> +++ b/gdbsupport/fileio.h >> @@ -120,9 +120,11 @@ using fio_time_t = char[FIO_TIME_LEN]; >> using fio_long_t = char[FIO_LONG_LEN]; >> using fio_ulong_t = char[FIO_ULONG_LEN]; >> >> -/* Struct stat as used in protocol. For complete independence >> - of host/target systems, it's defined as an array with offsets >> - to the members. */ >> +/* Struct stat as used in the protocol. This is the format used by the >> + F-packet file-i/o protocol, and by the vFile stat packets when the >> + stat64 feature has not been negotiated. Several fields are too narrow >> + to hold the corresponding struct stat member on a 64-bit host; see >> + struct fio_stat_wide. */ >> >> struct fio_stat >> { >> @@ -141,6 +143,29 @@ struct fio_stat >> fio_time_t fst_ctime; >> }; >> >> +/* Struct stat as used in the wide form of the protocol. The fields >> + which cannot hold the corresponding struct stat member on a 64-bit >> + host are widened to 8 bytes. This layout is only used by the vFile >> + stat packets, and only when the stat64 feature has been negotiated >> + with the peer. */ >> + >> +struct fio_stat_wide >> +{ >> + fio_ulong_t fst_dev; >> + fio_ulong_t fst_ino; >> + fio_mode_t fst_mode; >> + fio_ulong_t fst_nlink; >> + fio_uint_t fst_uid; >> + fio_uint_t fst_gid; >> + fio_ulong_t fst_rdev; >> + fio_ulong_t fst_size; >> + fio_ulong_t fst_blksize; >> + fio_ulong_t fst_blocks; >> + fio_ulong_t fst_atime; >> + fio_ulong_t fst_mtime; >> + fio_ulong_t fst_ctime; >> +}; >> + >> struct fio_timeval >> { >> fio_time_t ftv_sec; >> @@ -179,6 +204,20 @@ host_to_bigendian (LONGEST num, char *buf, int bytes) >> buf[i] = (num >> (8 * (bytes - i - 1))) & 0xff; >> } >> >> +/* Unpack an integer of BYTES bytes from BUF, which holds it in >> + big-endian, protocol format. */ >> + >> +static inline ULONGEST >> +bigendian_to_host (const char *buf, int bytes) >> +{ >> + ULONGEST num = 0; >> + int i; >> + >> + for (i = 0; i < bytes; ++i) >> + num = (num << 8) | (unsigned char) buf[i]; >> + return num; >> +} >> + >> /* Pack a host-format integer into an fio_uint_t. */ >> >> static inline void >> @@ -199,4 +238,13 @@ host_to_fileio_time (time_t num, fio_time_t fnum) >> >> extern void host_to_fileio_stat (struct stat *st, struct fio_stat *fst); >> >> +/* Pack a host-format struct stat into a struct fio_stat_wide. */ >> +extern void host_to_fileio_stat_wide (struct stat *st, >> + struct fio_stat_wide *fst); >> + >> +/* Narrow a struct fio_stat_wide into a struct fio_stat, warning if any >> + value does not fit. */ >> +extern void fileio_stat_wide_to_narrow (const struct fio_stat_wide *wide, >> + struct fio_stat *narrow); >> + >> #endif /* GDBSUPPORT_FILEIO_H */