[PATCH 1/2] Warn when accessing binaries over RSP

Gary Benson
2015-08-05T15:28:24Z

GDB provides no indicator of progress during file operations, and can
appear to have locked up during slow remote transfers. This commit
updates GDB to print a warning each time a file is accessed over RSP.
An additional message detailing how to avoid remote transfers is
printed for the first transfer only.

gdb/ChangeLog:

* gdb_bfd.c (gdb_bfd_iovec_fileio_open): Print warnings when
BFDs are opened via the remote protocol.

gdb/testsuite/ChangeLog:

* gdb.trace/pending.exp: Cope with remote transfer warnings.
---
gdb/ChangeLog | 5 +++++
gdb/gdb_bfd.c | 33 +++++++++++++++++++++++++++++----
gdb/testsuite/ChangeLog | 4 ++++
gdb/testsuite/gdb.trace/pending.exp | 8 ++++----
4 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/gdb/gdb_bfd.c b/gdb/gdb_bfd.c
index 1781d80..b511777 100644
--- a/gdb/gdb_bfd.c
+++ b/gdb/gdb_bfd.c
@@ -219,13 +219,38 @@ gdb_bfd_iovec_fileio_open (struct bfd *abfd, void *inferior)
const char *filename = bfd_get_filename (abfd);
int fd, target_errno;
int *stream;
+ struct target_ops *ops = find_target_at (process_stratum);

gdb_assert (is_target_filename (filename));
+ filename += strlen (TARGET_SYSROOT_PREFIX);
+
+ /* GDB provides no indicator of progress during file operations, and
+ can appear to have locked up during slow remote transfers, so we
+ inform the user what is happening and suggest a way out. It's
+ unpleasant that we need to detect remote targets this way (rather
+ than putting the warnings in remote_hostio_open), but it's not
+ possible for remote_hostio_open to differentiate between
+ accessing inferior binaries (which can be bypassed) and accessing
+ things like /proc/ (which is unavoidable). */
+ if (strcmp (ops->to_shortname, "remote") == 0
+ || strcmp (ops->to_shortname, "extended-remote") == 0)
+ {
+ static int warning_issued = 0;
+
+ printf_unfiltered (_("Reading %s from remote target\n"),
+ filename);
+
+ if (!warning_issued)
+ {
+ warning (_("File transfers from remote targets can be slow.\n"
+ "Use \"set sysroot\" to access files locally"
+ " instead."));
+ warning_issued = 1;
+ }
+ }

- fd = target_fileio_open ((struct inferior *) inferior,
- filename + strlen (TARGET_SYSROOT_PREFIX),
- FILEIO_O_RDONLY, 0,
- &target_errno);
+ fd = target_fileio_open ((struct inferior *) inferior, filename,
+ FILEIO_O_RDONLY, 0, &target_errno);
if (fd == -1)
{
errno = fileio_errno_to_host (target_errno);
diff --git a/gdb/testsuite/gdb.trace/pending.exp b/gdb/testsuite/gdb.trace/pending.exp
index 0399807..68e8c7b 100644
--- a/gdb/testsuite/gdb.trace/pending.exp
+++ b/gdb/testsuite/gdb.trace/pending.exp
@@ -221,7 +221,7 @@ proc pending_tracepoint_resolved_during_trace { trace_type } \
fail $test
}
}
- -re "Continuing.\r\n\r\nBreakpoint.*marker.*at.*$srcfile.*$gdb_prompt $" {
+ -re "Continuing.\r\n(Reading .* from remote target\r\n)?\r\nBreakpoint.*marker.*at.*$srcfile.*$gdb_prompt $" {
pass $test
}
}
@@ -294,7 +294,7 @@ proc pending_tracepoint_installed_during_trace { trace_type } \
fail $test
}
}
- -re "Continuing.\r\n\r\nBreakpoint.*marker.*at.*$srcfile.*$gdb_prompt $" {
+ -re "Continuing.\r\n(Reading .* from remote target\r\n)?\r\nBreakpoint.*marker.*at.*$srcfile.*$gdb_prompt $" {
pass $test
}
}
@@ -391,7 +391,7 @@ proc pending_tracepoint_disconnect_after_resolved { trace_type } \

gdb_test "continue" "Continuing.\r\n\r\nBreakpoint.*marker.*at.*pending.c.*" \
"continue to marker 1"
- gdb_test "continue" "Continuing.\r\n\r\nBreakpoint.*marker.*at.*pending.c.*" \
+ gdb_test "continue" "Continuing.\r\n(Reading .* from remote target\r\n)?\r\nBreakpoint.*marker.*at.*pending.c.*" \
"continue to marker 2"

# There should be no pending tracepoint, so no warning should be emitted.
@@ -473,7 +473,7 @@ proc pending_tracepoint_with_action_resolved { trace_type } \
fail $test
}
}
- -re "Continuing.\r\n\r\nBreakpoint.*marker.*at.*$srcfile.*$gdb_prompt $" {
+ -re "Continuing.\r\n(Reading .* from remote target\r\n)?\r\nBreakpoint.*marker.*at.*$srcfile.*$gdb_prompt $" {
pass "continue to marker 2"
}

--
1.7.1