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| author | Jan Kratochvil <jan.kratochvil@redhat.com> | 2016-04-27 21:27:40 +0200 |
|---|---|---|
| committer | Jan Kratochvil <jan.kratochvil@redhat.com> | 2016-04-27 21:27:40 +0200 |
| commit | 57809e5e5a506664eb54433ded81ab0785168a83 (patch) | |
| tree | b182387a6aaa5528d584b75b36b60f730f9c77a5 /gdb/remote.c | |
| parent | 91f8bf69a526912f86da81070407bba6a050e27f (diff) | |
| download | gdb-57809e5e5a506664eb54433ded81ab0785168a83.zip gdb-57809e5e5a506664eb54433ded81ab0785168a83.tar.gz gdb-57809e5e5a506664eb54433ded81ab0785168a83.tar.bz2 | |
Workaround gdbserver<7.7 for setfs
With current FSF GDB HEAD and old FSF gdbserver I expected I could do:
gdb -ex 'file target:/root/redhat/threadit' -ex 'target remote :1234'
(supplying that unsupported qXfer:exec-file:read by "file")
But that does not work because:
Sending packet: $vFile:setfs:0#bf...Packet received: OK
Packet vFile:setfs (hostio-setfs) is supported
...
Sending packet: $vFile:setfs:104#24...Packet received: OK
"target:/root/redhat/threadit": could not open as an executable file: Invalid argument
GDB documentation says:
The valid responses to Host I/O packets are:
An empty response indicates that this operation is not recognized.
This "empty response" vs. "OK" was a bug in gdbserver < 7.7. It was fixed by:
commit e7f0d979dd5cc4f8b658df892e93db69d6d660b7
Author: Yao Qi <yao@codesourcery.com>
Date: Tue Dec 10 21:59:20 2013 +0800
Fix a bug in matching notifications.
Message-ID: <1386684626-11415-1-git-send-email-yao@codesourcery.com>
https://sourceware.org/ml/gdb-patches/2013-12/msg00373.html
2013-12-10 Yao Qi <yao@codesourcery.com>
* notif.c (handle_notif_ack): Return 0 if no notification
matches.
with unpatched old FSF gdbserver and patched FSF GDB HEAD:
gdb -ex 'file target:/root/redhat/threadit' -ex 'target remote :1234'
Sending packet: $vFile:setfs:0#bf...Packet received: OK
Packet vFile:setfs (hostio-setfs) is NOT supported
...
(gdb) info sharedlibrary
From To Syms Read Shared Object Library
0x00007ffff7ddbae0 0x00007ffff7df627a Yes (*) target:/lib64/ld-linux-x86-64.so.2
0x00007ffff7bc48a0 0x00007ffff7bcf514 Yes (*) target:/lib64/libpthread.so.0
gdb/ChangeLog
2016-04-26 Jan Kratochvil <jan.kratochvil@redhat.com>
* remote.c (remote_start_remote): Detect PACKET_vFile_setfs.support.
Diffstat (limited to 'gdb/remote.c')
| -rw-r--r-- | gdb/remote.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/gdb/remote.c b/gdb/remote.c index 4c18b4f..1f0d67c 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -4031,6 +4031,25 @@ remote_start_remote (int from_tty, struct target_ops *target, int extended_p) if (packet_support (PACKET_QAllow) != PACKET_DISABLE) remote_set_permissions (target); + /* gdbserver < 7.7 (before its fix from 2013-12-11) did reply to any + unknown 'v' packet with string "OK". "OK" gets interpreted by GDB + as a reply to known packet. For packet "vFile:setfs:" it is an + invalid reply and GDB would return error in + remote_hostio_set_filesystem, making remote files access impossible. + Disable "vFile:setfs:" in such case. Do not disable other 'v' packets as + other "vFile" packets get correctly detected even on gdbserver < 7.7. */ + { + const char v_mustreplyempty[] = "vMustReplyEmpty"; + + putpkt (v_mustreplyempty); + getpkt (&rs->buf, &rs->buf_size, 0); + if (strcmp (rs->buf, "OK") == 0) + remote_protocol_packets[PACKET_vFile_setfs].support = PACKET_DISABLE; + else if (strcmp (rs->buf, "") != 0) + error (_("Remote replied unexpectedly to '%s': %s"), v_mustreplyempty, + rs->buf); + } + /* Next, we possibly activate noack mode. If the QStartNoAckMode packet configuration is set to AUTO, |