Go to file
Andrew Burgess 17cf289784 gdb/riscv: Handle errors while setting the frame id
When we connect to a remote target one of the first things GDB does is
establish a frame id.  If an error is thrown while building this frame
id then GDB will disconnect from the target.

This can mean that, if the user is attempting to connect to a target
that doesn't yet have a program loaded, or the program the user is
going to load onto the target doesn't match what is already loaded, or
the target is just in some undefined state, then the very first
request for a frame id can fail (for example, by trying to load from
an invalid memory address), and GDB will disconnect.  It is then
impossible for the user to connect to the target and load a new
program at all.

An example of such a session might look like this:

    Reading symbols from ./gdb/testsuite/outputs/gdb.arch/riscv-reg-aliases/riscv-reg-aliases...
    (gdb) target remote :37191
    Remote debugging using :37191
    0x0000000000000100 in ?? ()
    Cannot access memory at address 0x0
    (gdb) load
    You can't do that when your target is `exec'
    (gdb) info frame
    /path/to/gdb/gdb/thread.c:93: internal-error: thread_info* inferior_thread(): Assertion `tp' failed.
    A problem internal to GDB has been detected,
    further debugging may prove unreliable.
    Quit this debugging session? (y or n)

The solution is to handle errors in riscv_frame_this_id, and leave the
this_id variable with its default value, which is the predefined
'outermost' frame.

With this fix in place, connecting to the same target now looks like
this:

    (gdb) target remote :37191
    Remote debugging using :37191
    0x0000000000000100 in ?? ()
    (gdb) info frame
    Stack level 0, frame at 0x0:
     pc = 0x100; saved pc = <not saved>
     Outermost frame: outermost
     Arglist at unknown address.
     Locals at unknown address, Previous frame's sp in sp

gdb/ChangeLog:

	* riscv-tdep.c (riscv_insn::decode): Update header comment.
	(riscv_frame_this_id): Catch errors thrown while building the
	frame cache, leave the frame id as the default, which is the outer
	frame id.
2018-11-08 09:34:19 +00:00
bfd Automatic date update in version.in 2018-11-08 00:00:32 +00:00
binutils Enhance objdump's --disassemble switch so that it can now take an optional parameter, specifying the starting symbol for disassembly. Disassembly will continue from this symbol up to the next symbol. 2018-11-07 18:07:36 +00:00
config
contrib
cpu
elfcpp
etc
gas Add updated French and Portuguese translations. 2018-11-07 16:09:27 +00:00
gdb gdb/riscv: Handle errors while setting the frame id 2018-11-08 09:34:19 +00:00
gold Make gold testsuite work with CC and CXX specifying -B 2018-11-08 11:20:34 +10:30
gprof
include Add support for new load commands added by Apple to the MACH-O file format. 2018-11-07 15:20:22 +00:00
intl
ld elfedit: Add --enable-x86-feature/--disable-x86-feature 2018-11-06 09:38:51 -08:00
libdecnumber
libiberty
opcodes [BINUTILS, ARM] Add Armv8.5-A to select_arm_features and update macros. 2018-11-06 12:13:45 +00:00
readline
sim
texinfo
zlib
.cvsignore
.gitattributes
.gitignore
ar-lib
ChangeLog
compile
config-ml.in
config.guess
config.rpath
config.sub
configure
configure.ac
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4
lt~obsolete.m4
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS
Makefile.def
Makefile.in
Makefile.tpl
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
multilib.am
README
README-maintainer-mode
setup.com
src-release.sh
symlink-tree
test-driver
ylwrap

		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.