ppc: Fix signal delivery in ppc-user and ppc64-user

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

ppc: Fix signal delivery in ppc-user and ppc64-user

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>

show more ...

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160915' into staging

linux-user changes since 2.7 release

# gpg: Signature made Thu 22 Sep 2016 13:09:17 BST
# gpg:

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160915' into staging

linux-user changes since 2.7 release

# gpg: Signature made Thu 22 Sep 2016 13:09:17 BST
# gpg: using RSA key 0xB44890DEDE3C9BC0
# gpg: Good signature from "Riku Voipio <riku.voipio@iki.fi>"
# gpg: aka "Riku Voipio <riku.voipio@linaro.org>"
# Primary key fingerprint: FF82 03C8 C391 98AE 0581 41EF B448 90DE DE3C 9BC0

* remotes/riku/tags/pull-linux-user-20160915: (26 commits)
linux-user: fix TARGET_NR_select
linux-user: Fix incorrect offset of tuc_stack in ARM do_sigframe_return_v2
linux-user: Sanity check clone flags
linux-user: Remove unnecessary nptl_flags variable from do_fork()
linux-user: Implement force_sigsegv() via force_sig()
linux-user: SIGSEGV from sigreturn need not be fatal
linux-user: ARM: Give SIGSEGV if signal frame setup fails
linux-user: SIGSEGV on signal entry need not be fatal
linux-user: Pass si_type information to queue_signal() explicitly
linux-user: Recheck for pending synchronous signals too
linux-user: ppc64: set MSR_CM bit for BookE 2.06 MMU
linux-user: Use correct target SHMLBA in shmat()
linux-user: Use glib malloc functions in load_symbols()
linux-user: Check dump_write() return in elf_core_dump()
linux-user: Fix error handling in flatload.c target_pread()
linux-user: Fix incorrect use of host errno in do_ioctl_dm()
linux-user: Check lock_user() return value for NULL
linux-user: Pass missing MAP_ANONYMOUS to target_mmap() call
linux-user: report signals being taken in strace output
linux-user: Range check the nfds argument to ppoll syscall
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

linux-user: Fix incorrect offset of tuc_stack in ARM do_sigframe_return_v2

struct target_ucontext_v2 is not at the begining of the signal frame,
therefore do_sigaltstack was being passed bogus argum

linux-user: Fix incorrect offset of tuc_stack in ARM do_sigframe_return_v2

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>

show more ...

linux-user: Implement force_sigsegv() via force_sig()

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

linux-user: Implement force_sigsegv() via force_sig()

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>

show more ...

linux-user: SIGSEGV from sigreturn need not be fatal

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 cat

linux-user: SIGSEGV from sigreturn need not be fatal

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>

show more ...

linux-user: ARM: Give SIGSEGV if signal frame setup fails

The 32-bit ARM signal frame setup code was just bailing out
on error returns from lock_user_struct calls, without
generating the SIGSEGV tha

linux-user: ARM: Give SIGSEGV if signal frame setup fails

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>

show more ...

linux-user: SIGSEGV on signal entry need not be fatal

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

linux-user: SIGSEGV on signal entry need not be fatal

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>

show more ...

linux-user: Pass si_type information to queue_signal() explicitly

Instead of assuming in queue_signal() that all callers are passing
a siginfo structure which uses the _sifields._sigfault part of th

linux-user: Pass si_type information to queue_signal() explicitly

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>

show more ...

linux-user: Recheck for pending synchronous signals too

In process_pending_signals() we restart the scan of possible
pending signals after calling handle_pending_signal() in
case some other signal h

linux-user: Recheck for pending synchronous signals too

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>

show more ...

linux-user: report signals being taken in strace output

Native strace reports when the process being traced takes a signal:
--- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=0} ---

Repor

linux-user: report signals being taken in strace output

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>

show more ...

Merge remote-tracking branch 'remotes/mjt/tags/trivial-patches-fetch' into staging

trivial patches for 2016-09-15

# gpg: Signature made Thu 15 Sep 2016 13:40:55 BST
# gpg: using RSA

Merge remote-tracking branch 'remotes/mjt/tags/trivial-patches-fetch' into staging

trivial patches for 2016-09-15

# gpg: Signature made Thu 15 Sep 2016 13:40:55 BST
# gpg: using RSA key 0x701B4F6B1A693E59
# gpg: Good signature from "Michael Tokarev <mjt@tls.msk.ru>"
# gpg: aka "Michael Tokarev <mjt@corpit.ru>"
# gpg: aka "Michael Tokarev <mjt@debian.org>"
# Primary key fingerprint: 6EE1 95D1 886E 8FFB 810D 4324 457C E0A0 8044 65C5
# Subkey fingerprint: 7B73 BAD6 8BE7 A2C2 8931 4B22 701B 4F6B 1A69 3E59

* remotes/mjt/tags/trivial-patches-fetch: (21 commits)
mptsas: change .realize function name
linux-user/qemu.h: change malloc to g_malloc, free to g_free
win32: don't run subprocess tests on Mingw32 platform
sheepdog: remove useless casts
fw_cfg: remove useless casts
tricore: remove useless cast
s390x: remove useless cast
linux-user,s390x: remove useless cast
coccinelle: add a script to remove useless casts
curl: Operate on zero-length file
Remove unused function declarations
ivshmem: Delete duplicate debug message
sh4: fix broken link to documentation
MAINTAINERS: Fix up F: entry bit rot
MAINTAINERS: Add include/sysemu/cpus.h
MAINTAINERS: Add include/hw/sh4/ to SH4 section
MAINTAINERS: Add include/hw/tricore/ to TriCore section
MAINTAINERS: Add include/hw/unicore32/ to UniCore32 section
ui/console: Fix non-working backspace key in monitor of gtk UI
tcg: Remove duplicate header includes
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

linux-user,s390x: remove useless cast

This patch is the result of coccinelle script
scripts/coccinelle/typecast.cocci

CC: Riku Voipio <riku.voipio@iki.fi>
CC: Alexander Graf <agraf@suse.de>
Signed-

linux-user,s390x: remove useless cast

This patch is the result of coccinelle script
scripts/coccinelle/typecast.cocci

CC: Riku Voipio <riku.voipio@iki.fi>
CC: Alexander Graf <agraf@suse.de>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

show more ...

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160719-2' into staging

linux-user fixes before 2.7 freeze, fix commit message

# gpg: Signature made Tue 19 Jul 2016 14:18:54 BST
#

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160719-2' into staging

linux-user fixes before 2.7 freeze, fix commit message

# gpg: Signature made Tue 19 Jul 2016 14:18:54 BST
# gpg: using RSA key 0xB44890DEDE3C9BC0
# gpg: Good signature from "Riku Voipio <riku.voipio@iki.fi>"
# gpg: aka "Riku Voipio <riku.voipio@linaro.org>"
# Primary key fingerprint: FF82 03C8 C391 98AE 0581 41EF B448 90DE DE3C 9BC0

* remotes/riku/tags/pull-linux-user-20160719-2:
linux-user: AArch64 has sync_file_range, not sync_file_range2
linux-user: Fix type for SIOCATMARK ioctl
linux-user: define missing sparc syscalls
linux-user: Fix terminal control ioctls
linux-user: Add some new blk ioctls
linux-user: Handle short lengths in host_to_target_sockaddr()
linux-user: Forget about synchronous signal once it is delivered
linux-user: Correct type for LOOP_GET_STATUS{,64} ioctls
linux-user: Correct type for BLKSSZGET
linux-user: Add loop control ioctls
linux-user: Check sigsetsize argument to syscalls
linux-user: add nested netlink types
linux-user: convert sockaddr_ll from host to target
linux-user: add fd_trans helper in do_recvfrom()
linux-user: fix netlink memory corruption
linux-user: fd_trans_*_data() returns the length

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

linux-user: Forget about synchronous signal once it is delivered

Commit 655ed67c2a248cf which switched synchronous signals to
benig recorded in ts->sync_signal rather than in a queue
with every othe

linux-user: Forget about synchronous signal once it is delivered

Commit 655ed67c2a248cf 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>

show more ...

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160628' into staging

Drop building linux-user targets on HPPA or m68k host systems
and add safe_syscall support for i386, aarch64, a

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160628' into staging

Drop building linux-user targets on HPPA or m68k host systems
and add safe_syscall support for i386, aarch64, arm, ppc64 and
s390x.

# gpg: Signature made Tue 28 Jun 2016 19:31:16 BST
# gpg: using RSA key 0xB44890DEDE3C9BC0
# gpg: Good signature from "Riku Voipio <riku.voipio@iki.fi>"
# gpg: aka "Riku Voipio <riku.voipio@linaro.org>"
# Primary key fingerprint: FF82 03C8 C391 98AE 0581 41EF B448 90DE DE3C 9BC0

* remotes/riku/tags/pull-linux-user-20160628: (24 commits)
linux-user: Provide safe_syscall for ppc64
linux-user: Provide safe_syscall for s390x
linux-user: Provide safe_syscall for aarch64
linux-user: Provide safe_syscall for arm
linux-user: Provide safe_syscall for i386
linux-user: fix x86_64 safe_syscall
linux-user: don't swap NLMSG_DATA() fields
linux-user: fd_trans_host_to_target_data() must process only received data
linux-user: add missing return in netlink switch statement
linux-user: update get_thread_area/set_thread_area strace
linux-user: fix clone() strace
linux-user: add socket() strace
linux-user: add socketcall() strace
linux-user: Support F_GETPIPE_SZ and F_SETPIPE_SZ fcntls
linux-user: Fix wrong type used for argument to rt_sigqueueinfo
linux-user: Create a hostdep.h for each host architecture
user-exec: Remove unused code for OSX hosts
user-exec: Delete now-unused hppa and m68k cpu_signal_handler() code
configure: Don't allow user-only targets for unknown CPU architectures
configure: Don't override ARCH=unknown if enabling TCI
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

linux-user: Don't use sigfillset() on uc->uc_sigmask

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

linux-user: Don't use sigfillset() on uc->uc_sigmask

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>

show more ...

linux-user: Avoid possible misalignment in host_to_target_siginfo()

host_to_target_siginfo() is implemented by a combination of
host_to_target_siginfo_noswap() followed by tswap_siginfo().
The first

linux-user: Avoid possible misalignment in host_to_target_siginfo()

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>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2016-06-20' into staging

Error reporting patches for 2016-06-20

# gpg: Signature made Mon 20 Jun 2016 15:56:15 BST
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2016-06-20' into staging

Error reporting patches for 2016-06-20

# gpg: Signature made Mon 20 Jun 2016 15:56:15 BST
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2016-06-20:
log: Fix qemu_set_log_filename() error handling
log: Fix qemu_set_dfilter_ranges() error reporting
log: Plug memory leak on multiple -dfilter
coccinelle: Remove unnecessary variables for function return value
error: Remove unnecessary local_err variables
error: Remove NULL checks on error_propagate() calls
vl: Error messages need to go to stderr, fix some

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

coccinelle: Remove unnecessary variables for function return value

Use Coccinelle script to replace 'ret = E; return ret' with
'return E'. The script will do the substitution only when the
function

coccinelle: Remove unnecessary variables for function return value

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>

show more ...

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160608' into staging

linux-user pull request for June 2016

# gpg: Signature made Wed 08 Jun 2016 14:27:14 BST
# gpg:

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160608' into staging

linux-user pull request for June 2016

# gpg: Signature made Wed 08 Jun 2016 14:27:14 BST
# gpg: using RSA key 0xB44890DEDE3C9BC0
# gpg: Good signature from "Riku Voipio <riku.voipio@iki.fi>"
# gpg: aka "Riku Voipio <riku.voipio@linaro.org>"

* remotes/riku/tags/pull-linux-user-20160608: (44 commits)
linux-user: In fork_end(), remove correct CPUs from CPU list
linux-user: Special-case ERESTARTSYS in target_strerror()
linux-user: Make target_strerror() return 'const char *'
linux-user: Correct signedness of target_flock l_start and l_len fields
linux-user: Use safe_syscall wrapper for ioctl
linux-user: Use safe_syscall wrapper for accept and accept4 syscalls
linux-user: Use safe_syscall wrapper for semop
linux-user: Use safe_syscall wrapper for epoll_wait syscalls
linux-user: Use safe_syscall wrapper for poll and ppoll syscalls
linux-user: Use safe_syscall wrapper for sleep syscalls
linux-user: Use safe_syscall wrapper for rt_sigtimedwait syscall
linux-user: Use safe_syscall wrapper for flock
linux-user: Use safe_syscall wrapper for mq_timedsend and mq_timedreceive
linux-user: Use safe_syscall wrapper for msgsnd and msgrcv
linux-user: Use safe_syscall wrapper for send* and recv* syscalls
linux-user: Use safe_syscall wrapper for connect syscall
linux-user: Use safe_syscall wrapper for readv and writev syscalls
linux-user: Fix error conversion in 64-bit fadvise syscall
linux-user: Fix NR_fadvise64 and NR_fadvise64_64 for 32-bit guests
linux-user: Fix handling of arm_fadvise64_64 syscall
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Conflicts:
configure
scripts/qemu-binfmt-conf.sh

show more ...

linux-user: Avoid possible misalignment in target_to_host_siginfo()

Reimplement target_to_host_siginfo() to use __get_user(), which
handles possibly misaligned source guest structures correctly.

Re

linux-user: Avoid possible misalignment in target_to_host_siginfo()

Reimplement target_to_host_siginfo() to use __get_user(), which
handles possibly misaligned source guest structures correctly.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

show more ...

linux-user: Use both si_code and si_signo when converting siginfo_t

The siginfo_t struct includes a union. The correct way to identify
which fields of the union are relevant is complicated, because

linux-user: Use both si_code and si_signo when converting siginfo_t

The siginfo_t struct includes a union. The correct way to identify
which fields of the union are relevant is complicated, because we
have to use a combination of the si_code and si_signo to figure out
which of the union's members are valid. (Within the host kernel it
is always possible to tell, but the kernel carefully avoids giving
userspace the high 16 bits of si_code, so we don't have the
information to do this the easy way...) We therefore make our best
guess, bearing in mind that a guest can spoof most of the si_codes
via rt_sigqueueinfo() if it likes. Once we have made our guess, we
record it in the top 16 bits of the si_code, so that tswap_siginfo()
later can use it. tswap_siginfo() then strips these top bits out
before writing si_code to the guest (sign-extending the lower bits).

This fixes a bug where fields were sometimes wrong; in particular
the LTP kill10 test went into an infinite loop because its signal
handler got a si_pid value of 0 rather than the pid of the sending
process.

As part of this change, we switch to using __put_user() in the
tswap_siginfo code which writes out the byteswapped values to
the target memory, in case the target memory pointer is not
sufficiently aligned for the host CPU's requirements.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

show more ...

linux-user: Block signals during sigaction() handling

Block signals while emulating sigaction. This is a non-interruptible
syscall, and using block_signals() avoids races where the host
signal handl

linux-user: Block signals during sigaction() handling

Block signals while emulating sigaction. This is a non-interruptible
syscall, and using block_signals() avoids races where the host
signal handler is invoked and tries to examine the signal handler
data structures while we are updating them.

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-29-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: expanded commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

show more ...

linux-user: Queue synchronous signals separately

If a synchronous signal and an asynchronous signal arrive near simultaneously,
and the signal number of the asynchronous signal is lower than that of

linux-user: Queue synchronous signals separately

If a synchronous signal and an asynchronous signal arrive near simultaneously,
and the signal number of the asynchronous signal is lower than that of the
synchronous signal the the handler for the asynchronous would be called first,
and then the handler for the synchronous signal would be called within or
after the first handler with an incorrect context.

This is fixed by queuing synchronous signals separately. Note that this does
risk delaying a asynchronous signal until the synchronous signal handler
returns rather than handling the signal on another thread, but this seems
unlikely to cause problems for real guest programs and is unavoidable unless
we could guarantee to roll back and reexecute whatever guest instruction
caused the synchronous signal (which would be a bit odd if we've already
logged its execution, for instance, and would require careful analysis of
all guest CPUs to check it was possible in all cases).

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-24-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: added a comment]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

show more ...

linux-user: Remove real-time signal queuing

As host signals are now blocked whenever guest signals are blocked, the
queue of realtime signals is now in Linux. The QEMU queue is now
redundant and can

linux-user: Remove real-time signal queuing

As host signals are now blocked whenever guest signals are blocked, the
queue of realtime signals is now in Linux. The QEMU queue is now
redundant and can be removed. (We already did not queue non-RT signals, and
none of the calls to queue_signal() except the one in host_signal_handler()
pass an RT signal number.)

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-23-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: minor commit message tweak]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

show more ...