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[binutils-gdb] Fix 'xfered>0' assertion in target.c for remote connection
- From: Simon Marchi <simark at sourceware dot org>
- To: gdb-cvs at sourceware dot org
- Date: 14 Nov 2017 22:39:46 -0000
- Subject: [binutils-gdb] Fix 'xfered>0' assertion in target.c for remote connection
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=92ffd475192030a46a6046177c732372b4dadad5
commit 92ffd475192030a46a6046177c732372b4dadad5
Author: Paul Carroll <pcarroll@codesourcery.com>
Date: Tue Nov 14 17:37:37 2017 -0500
Fix 'xfered>0' assertion in target.c for remote connection
We have a customer who is using a Corelis gdb server to connect to gdb.
Occasionally, the gdb server will send a 0-byte block of memory for a
read. When this happens, gdb gives an assertion from target.c:
internal-error: target_xfer_partial: Assertion `*xfered_len > 0' failed.
This problem is almost identical to that fixed in
https://sourceware.org/ml/gdb-patches/2014-02/msg00636.html
In this case, remote.c needs to be modified to return TARGET_XFER_EOF
instead of TARGET_XFER_OK or TARGET_XFER_UNAVAILABLE when 0 bytes are
transferred.
gdb/ChangeLog:
PR gdb/22388
* remote.c (remote_write_bytes_aux, remote_read_bytes_1,
remote_read_bytes, remote_write_qxfer, remote_xfer_partial):
Return TARGET_XFER_EOF if size of returned data is 0.
Diff:
---
gdb/ChangeLog | 7 +++++++
gdb/remote.c | 11 ++++++-----
2 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 9a22ce7..6afec28 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2017-11-14 Paul Carroll <pcarroll@codesourcery.com>
+
+ PR gdb/22388
+ * remote.c (remote_write_bytes_aux, remote_read_bytes_1,
+ remote_read_bytes, remote_write_qxfer, remote_xfer_partial):
+ Return TARGET_XFER_EOF if size of returned data is 0.
+
2017-11-14 Simon Marchi <simon.marchi@ericsson.com>
* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
diff --git a/gdb/remote.c b/gdb/remote.c
index c653562..62ac055 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -8264,7 +8264,7 @@ remote_write_bytes_aux (const char *header, CORE_ADDR memaddr,
/* Return UNITS_WRITTEN, not TODO_UNITS, in case escape chars caused us to
send fewer units than we'd planned. */
*xfered_len_units = (ULONGEST) units_written;
- return TARGET_XFER_OK;
+ return (*xfered_len_units != 0) ? TARGET_XFER_OK : TARGET_XFER_EOF;
}
/* Write memory data directly to the remote machine.
@@ -8358,7 +8358,7 @@ remote_read_bytes_1 (CORE_ADDR memaddr, gdb_byte *myaddr, ULONGEST len_units,
decoded_bytes = hex2bin (p, myaddr, todo_units * unit_size);
/* Return what we have. Let higher layers handle partial reads. */
*xfered_len_units = (ULONGEST) (decoded_bytes / unit_size);
- return TARGET_XFER_OK;
+ return (*xfered_len_units != 0) ? TARGET_XFER_OK : TARGET_XFER_EOF;
}
/* Using the set of read-only target sections of remote, read live
@@ -8461,7 +8461,8 @@ remote_read_bytes (struct target_ops *ops, CORE_ADDR memaddr,
/* No use trying further, we know some memory starting
at MEMADDR isn't available. */
*xfered_len = len;
- return TARGET_XFER_UNAVAILABLE;
+ return (*xfered_len != 0) ?
+ TARGET_XFER_UNAVAILABLE : TARGET_XFER_EOF;
}
}
@@ -10386,7 +10387,7 @@ remote_write_qxfer (struct target_ops *ops, const char *object_name,
unpack_varlen_hex (rs->buf, &n);
*xfered_len = n;
- return TARGET_XFER_OK;
+ return (*xfered_len != 0) ? TARGET_XFER_OK : TARGET_XFER_EOF;
}
/* Read OBJECT_NAME/ANNEX from the remote target using a qXfer packet.
@@ -10687,7 +10688,7 @@ remote_xfer_partial (struct target_ops *ops, enum target_object object,
strcpy ((char *) readbuf, rs->buf);
*xfered_len = strlen ((char *) readbuf);
- return TARGET_XFER_OK;
+ return (*xfered_len != 0) ? TARGET_XFER_OK : TARGET_XFER_EOF;
}
/* Implementation of to_get_memory_xfer_limit. */