In order to debug funny kernel breakages it's always good to have a working
gdb stub around.
While Uli's patches don't include one one, I needed one that's at least good
enough for 'bt' and some variable examinations during early bootup.
So here it is - the absolute basics to get the qemu gdb stub running with s390x
targets.
Sgined-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We're leaking file descriptors to child processes. Set FD_CLOEXEC on file
descriptors that don't need to be passed to children to stop this misbehaviour.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The char event RESET is emitted when a char device is opened.
Give it a better name.
Patchworks-ID: 35287
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Commit 56aebc8916 changed gdbstub in way
that debugging 32 or 16-bit guest code is no longer possible with qemu
for x86_64 guest CPUs. Since that commit, qemu only provides registers
sets for 64-bit, forcing current and foreseeable gdb to also switch its
architecture to 64-bit. And this breaks if the inferior is 32 or 16 bit.
No question, this is a gdb issue. But, as it was confirmed in several
discusssions with gdb people, it is a non-trivial thing to fix. So until
qemu finds a gdb version attach with a rework x86 support, we have to
work around it by switching the register layout as the guest switches
its execution mode between 16/32 and 64 bit.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Put space between = and * when dereferencing a pointer,
to avoid confusion with old-style "*="
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
cpu_synchronize_state() is a little unreadable since the 'modified'
argument isn't self-explanatory. Simplify it by making it always
synchronize the kernel state into qemu, and automatically flush the
registers back to the kernel if they've been synchronized on this
exit.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This allows to set segment registers via gdb also in system emulation
mode. Basic sanity checks are applied and nothing is changed if they
fail. But screwing up the target via this interface will never be
complicated, so I avoided being too paranoid here.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Clarify gdb's register set layout by using constants for
cpu_gdb_read/write_register.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This patch adds support for the vCont remote gdb command. It is used by
gdb 6.8 or better to switch the debugging focus for single-stepping
multi-threaded targets, ie. multi-threaded application in user mode
emulation or VCPUs in system emulation.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
When debugging multi-threaded programs, QEMU's gdb stub would report the
correct number of threads (the qfThreadInfo and qsThreadInfo packets).
However, the stub was unable to actually switch between threads (the T
packet), since it would report every thread except the first as being
dead. Furthermore, the stub relied upon cpu_index as a reliable means
of assigning IDs to the threads. This was a bad idea; if you have this
sequence of events:
initial thread created
new thread #1
new thread #2
thread #1 exits
new thread #3
thread #3 will have the same cpu_index as thread #1, which would confuse
GDB. (This problem is partly due to the remote protocol not having a
good way to send thread creation/destruction events.)
We fix this by using the host thread ID for the identifier passed to GDB
when debugging a multi-threaded userspace program. The thread ID might
wrap, but the same sort of problems with wrapping thread IDs would come
up with debugging programs natively, so this doesn't represent a
problem.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
The code for handling the c and s packets both contain code for setting
the pc. Move that code out to a common function.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7039 c046a42c-6fe2-441c-8c8c-71466251a162
Introduce a more canonical gdbstub configuration (system emulation only)
via the new switch '-gdb dev'. Keep '-s' as shorthand for
'-gdb tcp::1234'. Use the same syntax also for the corresponding monitor
command 'gdbserver'. Its default remains to listen on TCP port 1234.
Changes in v4:
- Rebased over new command line switches meta file
Changes in v3:
- Fix documentation
Changes in v2:
- Support for pipe-based like to gdb (target remote | qemu -gdb stdio)
- Properly update the qemu-doc
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6992 c046a42c-6fe2-441c-8c8c-71466251a162
[ Note: depends on char closing fixes ]
Properly clean up the gdbstub when the user tries to re-open it
(possibly under a different address). Moreover, allow to shut it down
from the monitor via 'gdbserver none'.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6913 c046a42c-6fe2-441c-8c8c-71466251a162
This is a backport of the guest debugging support for the KVM
accelerator that is now part of the KVM tree. It implements the reworked
KVM kernel API for guest debugging (KVM_CAP_SET_GUEST_DEBUG) which is
not yet part of any mainline kernel but will probably be 2.6.30 stuff.
So far supported is x86, but PPC is expected to catch up soon.
Core features are:
- unlimited soft-breakpoints via code patching
- hardware-assisted x86 breakpoints and watchpoints
Changes in this version:
- use generic hook cpu_synchronize_state to transfer registers between
user space and kvm
- push kvm_sw_breakpoints into KVMState
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6825 c046a42c-6fe2-441c-8c8c-71466251a162
Create a monitor terminal and pass it through the gdbstub. This allows
to use gdb's monitor command to access the QEMU monitor. Works for all
commands except for non-detached migration and password retrieval (user
will receive error messages instead).
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6718 c046a42c-6fe2-441c-8c8c-71466251a162
Define GDB_CORE_XML and hack things similarly to ARM so that despite the
FP registers coming in between the GPRs and some status registers,
everything works out OK no matter which kind of GDB we're communicating
with.
It matters whether we're built to target 64-bit or 32-bit cores. I
think there are still problems if we are debugging 32-bit programs on a
built-for-64-bit QEMU (QEMU will always send 64-bit registers), but I
don't know if there's a good way around that at the time being.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6421 c046a42c-6fe2-441c-8c8c-71466251a162
And use it for the malta emulation. Fix segfault introduced in
revision 6352.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6365 c046a42c-6fe2-441c-8c8c-71466251a162
As reported by Martin Mohring fork doesn't work with NPTL.
A fix is attached that makes the also attached test run
(tested with ARM CodeSourcery 2008q3 on an x86_64
Fedora Core with kernel 2.6.23).
Signed-off-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6195 c046a42c-6fe2-441c-8c8c-71466251a162
The attached patch updates the FSF address in the GPL/LGPL boilerplate
in most GPL/LGPLed files, and also in COPYING.LIB.
Signed-off-by: Stuart Brady <stuart.brady@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6162 c046a42c-6fe2-441c-8c8c-71466251a162
Handle signals in the user-mode GDB stub. Report them to GDB, and
allow it to change or cancel them. Also correct the protocol numbering;
it happens to match Linux numbering for SIGINT and SIGTRAP, but that's
just good fortune.
Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6096 c046a42c-6fe2-441c-8c8c-71466251a162
Close gdbserver in child processes, so that only one stub tries to talk
to GDB at a time. Updated from an earlier patch by Paul Brook.
Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6095 c046a42c-6fe2-441c-8c8c-71466251a162
Obviously, someone forgot to rebase the index before accessing one of
the 32 FPRs.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5821 c046a42c-6fe2-441c-8c8c-71466251a162
This patch enhances QEMU's built-in debugger for SMP guest debugging.
Using the thread support of the gdb remote protocol, each VCPU is mapped
on a pseudo thread and exposed to the gdb frontend. This way you can
easy switch the focus of gdb between the VCPUs and observe their states.
On breakpoint hit, the focus is automatically adjusted just as for
normal multi-threaded application under gdb control.
Furthermore, the patch propagates breakpoint and watchpoint insertions
or removals to all CPUs, not just the current one as it was the case so
far. Without this, SMP guest debugging was practically unfeasible.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5743 c046a42c-6fe2-441c-8c8c-71466251a162
This patch prepares the QEMU cpu_watchpoint/breakpoint API to allow the
succeeding enhancements this series comes with.
First of all, it overcomes MAX_BREAKPOINTS/MAX_WATCHPOINTS by switching
to dynamically allocated data structures that are kept in linked lists.
This also allows to return a stable reference to the related objects,
required for later introduced x86 debug register support.
Breakpoints and watchpoints are stored with their full information set
and an additional flag field that makes them easily extensible for use
beyond pure guest debugging.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5738 c046a42c-6fe2-441c-8c8c-71466251a162
Return the appropriate type prefix (r, a, none) when reporting
watchpoint hits to the gdb front-end.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5737 c046a42c-6fe2-441c-8c8c-71466251a162
This patch makes qemu keep track of the character devices in use and
implements a "info chardev" monitor command to print a list.
qemu_chr_open() sticks the devices into a linked list now. It got a new
argument (label), so there is a name for each device. It also assigns a
filename to each character device. By default it just copyes the
filename passed in. Individual drivers can fill in something else
though. qemu_chr_open_pty() sets the filename to name of the pseudo tty
allocated.
Output looks like this:
(qemu) info chardev
monitor: filename=unix:/tmp/run.sh-26827/monitor,server,nowait
serial0: filename=unix:/tmp/run.sh-26827/console,server
serial1: filename=pty:/dev/pts/5
parallel0: filename=vc:640x480
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5575 c046a42c-6fe2-441c-8c8c-71466251a162
Define XER bits as a single register and access them individually to
avoid defining 5 32-bit registers (TCG doesn't permit to map 8-bit
registers).
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5500 c046a42c-6fe2-441c-8c8c-71466251a162
