In commit 8c5931de0a we added support for SVE extended
sigframe records. These mean that the signal frame might now be
larger than the size of the target_rt_sigframe record, so make sure
we call lock_user on the entire frame size when we're creating it.
(The code for restoring the signal frame already correctly handles
the extended records by locking the 'extra' section separately to the
main section.)
In particular, this fixes a bug even for non-SVE signal frames,
because it extends the locked section to cover the
target_rt_frame_record. Previously this was part of 'struct
target_rt_sigframe', but in commit e1eecd1d9d we pulled
it out into its own struct, and so locking the target_rt_sigframe
alone doesn't cover it. This bug would mean that we would fail
to correctly handle the case where a signal was taken with
SP pointing 16 bytes into an unwritable page, with the page
immediately below it in memory being writable.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
AArch64 stack frames include a 'frame record' which holds a pointer
to the next frame record in the chain and the LR on entry to the
function. The procedure calling standard doesn't mandate where
exactly this frame record is in the stack frame, but for signal
frames the kernel puts it right at the top. We used to put it
there too, but in commit 7f0f4208b3 we accidentally put
the "enlarge to the 4K reserved space minimum" check after the
"allow for the frame record" code, rather than before it, with
the effect that the frame record would be inside the reserved
space and immediately after the last used part of it.
Move the frame record back out of the reserved space to where
we used to put it.
This bug shouldn't break any sensible guest code, but test
programs that deliberately look at the internal details
of the signal frame layout will not find what they are
expecting to see.
Fixes: 7f0f4208b3
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-id: 20180412140222.2096-1-peter.maydell@linaro.org
The AArch64 signal frame design was extended for SVE in commit
8c5931de0a, so that instead of having a fixed setup we
now add various records to the frame, with some of them possibly
overflowing into an extra space outside the original 4K reserved
block in the target_sigcontext. However, we failed to ensure that we
always at least allocate the 4K reserved block. This is ABI, and
some userspace programs rely on it. In particular the dash shell
would segfault if the frame wasn't as big enough.
(Compare the kernel's sigframe_size() function in
arch/arm64/kernel/signal.c.)
Reported-by: Richard Henwood <richard.henwood@arm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180409140714.26841-1-peter.maydell@linaro.org
Fixes: https://bugs.launchpad.net/bugs/1761535
Fixes: 8c5931de0a
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Sparc as an extended sigaction structure containing
the field ka_restorer used in place of sa_restorer.
Define TARGET_ARCH_HAS_KA_RESTORER and use it
with sparc.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180402102453.9883-2-laurent@vivier.eu>
setup_frame() doesn't set correctly the address of the trampoline code.
The offset of retcode array must be added to the stack frame address.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180401204653.14211-1-laurent@vivier.eu>
flush_window_regs uses wrong stack frame to save overflow registers in
call8 and call12 frames, which results in wrong register values in
callers of a function that received a signal.
Reimplement flush_window_regs closely following window overflow
sequence.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
target/xtensa linux-user support.
- small cleanup for xtensa registers dumping (-d cpu);
- add support for debugging linux-user process with xtensa-linux-gdb
(as opposed to xtensa-elf-gdb), which can only access unprivileged
registers;
- enable MTTCG for target/xtensa;
- cleanup in linux-user/mmap area making sure that it works correctly
with limited 30-bit-wide user address space;
- import xtensa-specific definitions from the linux kernel,
conditionalize user-only/softmmu-only code and add handlers for
signals, exceptions, process/thread creation and core registers dumping.
# gpg: Signature made Fri 16 Mar 2018 16:46:19 GMT
# gpg: using RSA key 51F9CC91F83FA044
# gpg: Good signature from "Max Filippov <filippov@cadence.com>"
# gpg: aka "Max Filippov <max.filippov@cogentembedded.com>"
# gpg: aka "Max Filippov <jcmvbkbc@gmail.com>"
# Primary key fingerprint: 2B67 854B 98E5 327D CDEB 17D8 51F9 CC91 F83F A044
* remotes/xtensa/tags/20180316-xtensa:
MAINTAINERS: fix W: address for xtensa
qemu-binfmt-conf.sh: add qemu-xtensa
target/xtensa: add linux-user support
linux-user: drop unused target_msync function
linux-user: fix target_mprotect/target_munmap error return values
linux-user: fix assertion in shmdt
linux-user: fix mmap/munmap/mprotect/mremap/shmat
target/xtensa: support MTTCG
target/xtensa: use correct number of registers in gdbstub
target/xtensa: mark register windows in the dump
target/xtensa: dump correct physical registers
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
# Conflicts:
# linux-user/syscall.c
Import list of syscalls from the kernel source. Conditionalize code/data
that is only used with softmmu. Implement exception handlers. Implement
signal hander (only the core registers for now, no coprocessors or TIE).
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
# gpg: Signature made Tue 13 Mar 2018 17:33:03 GMT
# gpg: using RSA key F30C38BD3F2FBE3C
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>"
# gpg: aka "Laurent Vivier <laurent@vivier.eu>"
# gpg: aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>"
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F 5173 F30C 38BD 3F2F BE3C
* remotes/vivier2/tags/linux-user-for-2.12-pull-request:
linux-user: init_guest_space: Add a comment about search strategy
linux-user: init_guest_space: Don't try to align if we'll reject it
linux-user: init_guest_space: Clean up control flow a bit
linux-user: init_guest_commpage: Add a comment about size check
linux-user: init_guest_space: Clarify page alignment logic
linux-user: init_guest_space: Correctly handle guest_start in commpage initialization
linux-user: init_guest_space: Clean up if we can't initialize the commpage
linux-user: Rename validate_guest_space => init_guest_commpage
linux-user: Use #if to only call validate_guest_space for 32-bit ARM target
qemu-binfmt-conf.sh: add qemu-xtensa
linux-user: drop unused target_msync function
linux-user: fix target_mprotect/target_munmap error return values
linux-user: fix assertion in shmdt
linux-user: fix mmap/munmap/mprotect/mremap/shmat
linux-user: Support f_flags in statfs when available.
linux-user: allows to use "--systemd ALL" with qemu-binfmt-conf.sh
linux-user: Remove the unused "not implemented" signal handling stubs
linux-user: Drop unicore32 code
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Now we've dropped unicore32, all of the architectures we support
for linux-user implement the signal handling routines. The
dummy "just print a message" versions are unimplemented, so we
can drop them entirely.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180308144733.25615-3-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This changes the qemu signal frame layout to be more like the kernel's,
in that the various records are dynamically allocated rather than fixed
in place by a structure.
For now, all of the allocation is out of uc.tuc_mcontext.__reserved,
so the allocation is actually trivial. That will change with SVE support.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180303143823.27055-4-richard.henderson@linaro.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The SPARC code in linux-user/signal.c defines a set of
MC_* constants. On some SPARC hosts these are also defined
by sys/ucontext.h, resulting in build failures:
linux-user/signal.c:2786:0: error: "MC_NGREG" redefined [-Werror]
#define MC_NGREG 19
In file included from /usr/include/signal.h:302:0,
from include/qemu/osdep.h:86,
from linux-user/signal.c:19:
/usr/include/sparc64-linux-gnu/sys/ucontext.h:59:0: note: this is the location of the previous definition
# define MC_NGREG __MC_NGREG
Rename all these constants to SPARC_MC_* to avoid the clash.
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1517318239-15764-1-git-send-email-peter.maydell@linaro.org
Since for aarch64 the signal trampoline is synthesized directly into the
signal frame we need to make sure the instructions end up little-endian.
Otherwise the wrong endianness will cause a SIGILL upon return from the
signal handler on big-endian targets.
Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20171220212308.12614-4-michael.weiser@gmx.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Thanks to Laszlo Ersek for spotting the double semicolon in target/i386/kvm.c
I have trivially grepped the tree for ';;' in C files.
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reading and writing to an sa_restorer member that isn't supposed to
exist corrupts user memory. Introduce TARGET_ARCH_HAS_SA_RESTORER,
similar to the kernel's __ARCH_HAS_SA_RESTORER.
Reported-by: Helge Deller <deller@gmx.de>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If a signal is delivered during the execution of a delay slot,
or a gUSA region, clear those bits from the environment so that
the signal handler does not start in that same state.
Cleaning the bits on signal return is paranoid good sense.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-10-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
We translate gUSA regions atomically in a parallel context.
But in a serial context a gUSA region may be interrupted.
In that case, restart the region as the kernel would.
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170718200255.31647-9-rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Shadow registers are part of the openrisc spec along with sr[cid], as
part of the fast context switching feature. When exceptions occur,
instead of having to save registers to the stack if enabled the CID will
increment and a new set of registers will be available.
This patch only implements shadow registers which can be used as extra
scratch registers via the mfspr and mtspr if required. This is
implemented in a way where it would be easy to add on the fast context
switching, currently cid is hardcoded to 0.
This is need for openrisc linux smp kernels to boot correctly.
Signed-off-by: Stafford Horne <shorne@gmail.com>
do_rt_sigreturn uses an uninitialised local variable instead of fetching
the old signal mask directly from the signal frame when restoring the mask,
so the signal mask is undefined after do_rt_sigreturn. As the signal
frame data is in target-endian order, target_to_host_sigset instead of
target_to_host_sigset_internal is required.
do_sigreturn is correct in using target_to_host_sigset_internal, because
get_user already did the endianness conversion.
Signed-off-by: Michael Karcher <karcher@physik.fu-berlin.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20170225110517.2832-3-laurent@vivier.eu>
A segfault is noticed when an emulated program uses any of ucontext
regs fields. Risu detected this issue in the following operation when
handling a signal:
ucontext_t *uc = (ucontext_t*)uc;
uc->uc_mcontext.regs->nip += 4;
but this works fine:
uc->uc_mcontext.gp_regs[PT_NIP] += 4;
This patch set regs to a valid location as well as other sigcontext
fields.
Signed-off-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <1485900317-3256-1-git-send-email-joserz@linux.vnet.ibm.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
There were a number of bugs in the implementation:
- The structure alignment was wrong for 64-bit.
- Also 64-bit only does RT signals.
- On 64-bit, we need to put a pointer to the (aligned) vector registers
in the frame and use it for restoring
- We had endian bugs when saving/restoring vector registers
- My recent fixes for exception NIP broke sigreturn in user mode
causing us to resume one instruction too far.
- Add VSR second halves
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
struct target_ucontext_v2 is not at the begining of the signal frame,
therefore do_sigaltstack was being passed bogus arguments.
As the offset depends on the type of signal frame fixed by passing in the
beginning of the context from do_sigreturn_v2 and do_rt_sigreturn_v2.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Now that we have a force_sig() with the semantics we need,
we can implement force_sigsegv() to call it rather than
open-coding the call to queue_signal().
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If the sigreturn syscall fails to read memory then this causes a
SIGSEGV, but this is not necessarily a fatal signal -- the guest
process can catch it.
We don't implement this correctly because the behaviour of QEMU's
force_sig() function has drifted away from the kernel function of the
same name -- ours now does "always do a guest core dump and abort
execution", whereas the kernel version simply forces the guest to
take a signal, which may or may not eventually cause a core dump.
Rename our force_sig() to dump_core_and_abort(), and provide a
force_sig() which acts more like the kernel version as the sigreturn
implementations expect it to. Since force_sig() now returns, we must
update all the callsites to return -TARGET_QEMU_ESIGRETURN so that
the main loop doesn't change the guest registers before the signal
handler is invoked.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The 32-bit ARM signal frame setup code was just bailing out
on error returns from lock_user_struct calls, without
generating the SIGSEGV that should happen here. Wire up
error return codes to call force_sigsegv().
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
A failed write to memory trying to set up the signal frame
should trigger a SIGSEGV, but this need not be fatal: the
guest has a chance to catch it. Implement this via a force_sigsegv()
function with the same behaviour as the kernel function of that
name: make sure that we don't try to re-take a failed SIGSEGV,
and force a synchronous signal.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Instead of assuming in queue_signal() that all callers are passing
a siginfo structure which uses the _sifields._sigfault part of the
union (and thus a si_type of QEMU_SI_FAULT), make callers pass
the si_type they require in as an argument.
[RV adjusted to apply]
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
In process_pending_signals() we restart the scan of possible
pending signals after calling handle_pending_signal() in
case some other signal has been generated. This rescan
should also include a check for a new synchronous signal
since those are in fact the only kind of new signal that
the signal frame setup process might produce.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Native strace reports when the process being traced takes a signal:
--- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---
Report something similar when QEMU is doing its internal strace of
the guest process and is about to deliver it a signal.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Commit 655ed67c2a which switched synchronous signals to
benig recorded in ts->sync_signal rather than in a queue
with every other signal had a bug: we failed to clear
the flag indicating that a synchronous signal was pending
when we delivered it. This meant that we would take the signal
again and again every time the guest made a syscall.
(This is a bug introduced in my refactoring of Timothy Baldwin's
original code.)
Fix this by passing in the struct emulated_sigtable* to
handle_pending_signal(), so that we clear the pending flag
in the ts->sync_signal struct when handling a synchronous signal.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The kernel and libc have different ideas about what a sigset_t
is -- for the kernel it is only _NSIG / 8 bytes in size (usually
8 bytes), but for libc it is much larger, 128 bytes. In most
situations the difference doesn't matter, because if you pass a
pointer to a libc sigset_t to the kernel it just acts on the first
8 bytes of it, but for the ucontext_t* argument to a signal handler
it trips us up. The kernel allocates this ucontext_t on the stack
according to its idea of the sigset_t type, but the type of the
ucontext_t defined by the libc headers uses the libc type, and
so do the manipulator functions like sigfillset(). This means that
(1) sizeof(uc->uc_sigmask) is much larger than the actual
space used on the stack
(2) sigfillset(&uc->uc_sigmask) will write garbage 0xff bytes
off the end of the structure, which can trash data that
was on the stack before the signal handler was invoked,
and may result in a crash after the handler returns
To avoid this, we use a memset() of the correct size to fill
the signal mask rather than using the libc function.
This fixes a problem where we would crash at least some of the
time on an i386 host when a signal was taken.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
host_to_target_siginfo() is implemented by a combination of
host_to_target_siginfo_noswap() followed by tswap_siginfo().
The first of these two functions assumes that the target_siginfo_t
it is writing to is correctly aligned, but the pointer passed
into host_to_target_siginfo() is directly from the guest and
might be misaligned. Use a local variable to avoid this problem.
(tswap_siginfo() does now correctly handle a misaligned destination.)
We have to add a memset() to host_to_target_siginfo_noswap()
to avoid some false positive "may be used uninitialized" warnings
from gcc about subfields of the _sifields union if it chooses to
inline both tswap_siginfo() and host_to_target_siginfo_noswap()
into host_to_target_siginfo().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Peter Maydell <riku.voipio@linaro.org>
Use Coccinelle script to replace 'ret = E; return ret' with
'return E'. The script will do the substitution only when the
function return type and variable type are the same.
Manual fixups:
* audio/audio.c: coding style of "read (...)" and "write (...)"
* block/qcow2-cluster.c: wrap line to make it shorter
* block/qcow2-refcount.c: change indentation of wrapped line
* target-tricore/op_helper.c: fix coding style of
"remainder|quotient"
* target-mips/dsp_helper.c: reverted changes because I don't
want to argue about checkpatch.pl
* ui/qemu-pixman.c: fix line indentation
* block/rbd.c: restore blank line between declarations and
statements
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-4-git-send-email-ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Unused Coccinelle rule name dropped along with a redundant comment;
whitespace touched up in block/qcow2-cluster.c; stale commit message
paragraph deleted]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
