Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230206223502.25122-6-philmd@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Applications do call sendmsg() without any IOV, e.g.:
sendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=NULL, msg_iovlen=0,
msg_control=[{cmsg_len=36, cmsg_level=SOL_ALG, cmsg_type=0x2}],
msg_controllen=40, msg_flags=0}, MSG_MORE) = 0
sendmsg(4, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="The quick brown fox jumps over t"..., iov_len=183}],
msg_iovlen=1, msg_control=[{cmsg_len=20, cmsg_level=SOL_ALG, cmsg_type=0x3}],
msg_controllen=24, msg_flags=0}, 0) = 183
The function do_sendrecvmsg_locked() is used for sndmsg() and recvmsg()
and calls lock_iovec() to lock the IOV into memory. For the first
sendmsg() above it returns NULL and thus wrongly skips the call the host
sendmsg() syscall, which will break the calling application.
Fix this issue by:
- allowing sendmsg() even with empty IOV
- skip recvmsg() if IOV is NULL
- skip both if the return code of do_sendrecvmsg_locked() != 0, which
indicates some failure like EFAULT on the IOV
Tested with the debian "ell" package with hppa guest on x86_64 host.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20221212173416.90590-2-deller@gmx.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Add suport to handle SOL_ALG packets via sendmsg() and recvmsg().
This allows emulated userspace to use encryption functionality.
Tested with the debian ell package with hppa guest on x86_64 host.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20221212173416.90590-1-deller@gmx.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Both parameters have a different value on the parisc platform, so first
translate the target value into a host value for usage in the native
madvise() syscall.
Those parameters are often used by security sensitive applications (e.g.
tor browser, boringssl, ...) which expect the call to return a proper
return code on failure, so return -EINVAL if qemu fails to forward the
syscall to the host OS.
While touching this code, enhance the comments about MADV_DONTNEED.
Tested with testcase of tor browser when running hppa-linux guest on
x86-64 host.
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <Y5iwTaydU7i66K/i@p100>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Make the strace look nicer for those two syscalls.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <Y9QxskymWJjrKQmT@p100>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The hppa architectures provides an own output for the emulated
/proc/cpuinfo file.
Some userspace applications count (even if that's not the recommended
way) the number of lines which start with "processor:" and assume that
this number then reflects the number of online CPUs. Since those 3
architectures don't provide any such line, applications may assume "0"
CPUs. One such issue can be seen in debian bug report:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1024653
Avoid such issues by adding a "processor:" line for each of the online
CPUs.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <Y9QvyRSq1I1k5/JW@p100>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Add translation for the host error return code of:
getsockopt(19, SOL_SOCKET, SO_ERROR, [ECONNREFUSED], [4]) = 0
This fixes the testsuite of the cockpit debian package with a
hppa-linux guest on a x86-64 host.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <Y9QzNzXg0hrzHQeo@p100>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This makes target_flat.h behave like every other target_xxx.h header.
It also makes it actually work -- while the current header says adding
a header to the target subdir overrides the common one, it doesn't.
This is for two reasons:
* meson.build adds -Ilinux-user before -Ilinux-user/$arch
* the compiler search path for "target_flat.h" looks in the same dir
as the source file before searching -I paths.
This can be seen with the xtensa port -- the subdir settings aren't
used which breaks stack setup.
Move it to the generic/ subdir and add include stubs like every
other target_xxx.h header is handled.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230129004625.11228-1-vapier@gentoo.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This reverts commit 3cd3df2a95.
glibc has fixed (in 2.36.9000-40-g774058d729) the problem
that caused a clash when both sys/mount.h annd linux/mount.h
are included, and backported this to the 2.36 stable release
too:
https://sourceware.org/glibc/wiki/Release/2.36#Usage_of_.3Clinux.2Fmount.h.3E_and_.3Csys.2Fmount.h.3E
It is saner for QEMU to remove the workaround it applied for
glibc 2.36 and expect distros to ship the 2.36 maint release
with the fix. This avoids needing to add a further workaround
to QEMU to deal with the fact that linux/brtfs.h now also pulls
in linux/mount.h via linux/fs.h since Linux 6.1
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230110174901.2580297-3-berrange@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This reverts commit c5495f4ecb.
glibc has fixed (in 2.36.9000-40-g774058d729) the problem
that caused a clash when both sys/mount.h annd linux/mount.h
are included, and backported this to the 2.36 stable release
too:
https://sourceware.org/glibc/wiki/Release/2.36#Usage_of_.3Clinux.2Fmount.h.3E_and_.3Csys.2Fmount.h.3E
It is saner for QEMU to remove the workaround it applied for
glibc 2.36 and expect distros to ship the 2.36 maint release
with the fix. This avoids needing to add a further workaround
to QEMU to deal with the fact that linux/brtfs.h now also pulls
in linux/mount.h via linux/fs.h since Linux 6.1
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230110174901.2580297-2-berrange@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Currently, qemu strace only prints four protocol contants. This patch
adds others listed in "linux/netlink.h".
Signed-off-by: Letu Ren <fantasquex@gmail.com>
Message-Id: <20230101141105.12024-1-fantasquex@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This reinstates commit 52f0c16076:
While forcing the CPU to unrealize by hand does trigger the clean-up
code we never fully free resources because refcount never reaches
zero. This is because QOM automatically added objects without an
explicit parent to /unattached/, incrementing the refcount.
Instead of manually triggering unrealization just unparent the object
and let the device machinery deal with that for us.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/866
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220811151413.3350684-2-alex.bennee@linaro.org>
The original patch tickled a problem in target/arm, and was reverted.
But that problem is fixed as of commit 3b07a936d3.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230124201019.3935934-1-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
execve() is a particular case of execveat(). In order
to add do_execveat(), first factor do_execve() out.
Signed-off-by: Drew DeVault <sir@cmpwn.com>
Message-Id: <20221104081015.706009-1-sir@cmpwn.com>
[PMD: Split of bigger patch, filled description, fixed style]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20221104173632.1052-5-philmd@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
In order to add print_execveat() which re-use common code from
print_execve(), extract print_execve_argv() from it.
Signed-off-by: Drew DeVault <sir@cmpwn.com>
Message-Id: <20221104081015.706009-1-sir@cmpwn.com>
[PMD: Split of bigger patch, filled description, fixed style]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20221104173632.1052-3-philmd@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This commit re-enables ppc32 as a linux-user host,
as existance of the directory is noted by configure.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1097
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220729172141.1789105-3-richard.henderson@linaro.org>
Add ability to dump /tmp/perf-<pid>.map and jit-<pid>.dump.
The first one allows the perf tool to map samples to each individual
translation block. The second one adds the ability to resolve symbol
names, line numbers and inspect JITed code.
Example of use:
perf record qemu-x86_64 -perfmap ./a.out
perf report
or
perf record -k 1 qemu-x86_64 -jitdump ./a.out
DEBUGINFOD_URLS= perf inject -j -i perf.data -o perf.data.jitted
perf report -i perf.data.jitted
Co-developed-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>
Co-developed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230112152013.125680-4-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Add libdw-based functions for loading and querying debuginfo. Load
debuginfo from the system and the linux-user loaders.
This is useful for the upcoming perf support, which can then put
human-readable guest symbols instead of raw guest PCs into perfmap and
jitdump files.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230112152013.125680-3-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
When exiting due to an exit() syscall, qemu-user calls
preexit_cleanup(), but this is currently not the case when exiting due
to a signal. This leads to various buffers not being flushed (e.g.,
for gprof, for gcov, and for the upcoming perf support).
Add the missing call.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230112152013.125680-2-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This patch fixes the issue originally reported in
this thread:
https://lists.gnu.org/archive/html/qemu-devel/2021-11/msg01102.html
The root cause of the issue is a bug in the hexagon specific
logic for saving & restoring context during signal delivery.
The CPU state has two different representations for the
predicate registers. The current logic saves & restores only
the aliased HEX_REG_P3_O register, which is part of env->gpr[]
field in the CPU state, but not the individual byte-level
predicate registers (pO, p1, p2, p3) backed by env->pred[].
Since all predicated instructions refer only to the
indiviual registers, switching to and back from a signal handler
can clobber these registers if the signal handler writes to them
causing the normal application code to behave unpredictably when
context is restored.
In the reported issue with the 'signals' test, since the updated
hexagon toolchain had built musl with -O2, the functions called
from non_trivial_free were inlined. This meant that the code
emitted reused predicate P0 computed in the entry translation
block of the function non_trivial_free in one of the child TB
as part of an assertion. Since P0 is clobbered by the signal
handler in the signals test, the assertion in non_trivial_free
fails incorectly. Since musl for hexagon implements the 'abort'
function by deliberately writing to memory via null pointer,
this causes the test to fail with segmentation fault.
This patch modifies the signal context save & restore logic
to include the individual p0, p1, p2, p3 and excludes the
32b p3_0 register since its value is derived from the former
registers. It also adds a new test case that reliabily
reproduces the issue for all four predicate registers.
Buglink: https://github.com/quic/toolchain_for_hexagon/issues/6
Signed-off-by: Mukilan Thiyagarajan <quic_mthiyaga@quicinc.com>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20221229092006.10709-2-quic_mthiyaga@quicinc.com>
It's possible that a message contains both normal payload and ancillary
data in the same message, and even if no ancillary data is available
this information should be passed to the target, otherwise the target
cmsghdr will be left uninitialized and the target is going to access
uninitialized memory if it expects cmsg.
Always call the function that translate cmsg when recvmsg, because that
function should be empty-cmsg-safe (it creates an empty cmsg in the
target).
Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20221028081220.1604244-1-uwu@icenowy.me>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The glibc on the hppa platform uses the "iitlbp %r0,(%sr0, %r0)"
assembler instruction as ABORT_INSTRUCTION.
If this (in userspace context) illegal assembler statement is found,
dump the registers and report the failure to userspace the same way as
the Linux kernel on physical hardware.
For other illegal instructions report TARGET_ILL_ILLOPC instead of
TARGET_ILL_ILLOPN as si_code.
Additionally add the missing EXCP_BREAK exception handler which occurs
when the "break x,y" assembler instruction is executed and report
EXCP_ASSIST traps.
Signed-off-by: Helge Deller <deller@gmx.de>
Message-Id: <Y1osHVsylkuZNUnY@p100>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
When PAGE_RESET is set, we are replacing pages with new
content, which means that we need to invalidate existing
cached data, such as TranslationBlocks. Perform the
reset invalidate while we're doing other invalidates,
which allows us to remove the separate invalidates from
the user-only mmap/munmap/mprotect routines.
In addition, restrict invalidation to PAGE_EXEC pages.
Since cdf7130851, we have validated PAGE_EXEC is present
before translation, which means we can assume that if the
bit is not present, there are no translations to invalidate.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
When the emulation stops with a hard exception it's very useful for
debugging purposes to dump the current guest memory layout (for an
example see /proc/self/maps) beside the CPU registers.
The open_self_maps() function provides such a memory dump, but since
it's located in the syscall.c file, various changes (add #includes, make
this function externally visible, ...) are needed to be able to call it
from the existing EXCP_DUMP() macro.
This patch takes another approach by re-defining EXCP_DUMP() to call
target_exception_dump(), which is in syscall.c, consolidates the log
print functions and allows to add the call to dump the memory layout.
Beside a reduced code footprint, this approach keeps the changes across
the various callers minimal, and keeps EXCP_DUMP() highlighted as
important macro/function.
Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <Y1bzAWbw07WBKPxw@p100>
[lv: remove pc declaration and setting]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
User space has been preferring this syscall for a while, due to its
closer match with C semantics, and newer platforms such as LoongArch
apparently have libc implementations that don't fallback to faccessat
so normal access checks are failing without the emulation in place.
Tested by successfully emerging several packages within a Gentoo loong
stage3 chroot, emulated on amd64 with help of static qemu-loongarch64.
Reported-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Signed-off-by: WANG Xuerui <xen0n@gentoo.org>
Message-Id: <20221009060813.2289077-1-xen0n@gentoo.org>
[lv: removing defined(__NR_faccessat2) in syscall.c,
adding defined(TARGET_NR_faccessat2) on print_faccessat()]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
These ioctls have been defined in linux/fs.h for a long time
* BLKGETSIZE64 - <2.6.12 (linux.git epoch)
* BLKDISCARD - 2.6.28 (d30a2605be9d5132d95944916e8f578fcfe4f976)
* BLKIOMIN - 2.6.32 (ac481c20ef8f6c6f2be75d581863f40c43874ef7)
* BLKIOOPT - 2.6.32 (ac481c20ef8f6c6f2be75d581863f40c43874ef7)
* BLKALIGNOFF - 2.6.32 (ac481c20ef8f6c6f2be75d581863f40c43874ef7)
* BLKPBSZGET - 2.6.32 (ac481c20ef8f6c6f2be75d581863f40c43874ef7)
* BLKDISCARDZEROES - 2.6.32 (98262f2762f0067375f83824d81ea929e37e6bfe)
* BLKSECDISCARD - 2.6.36 (8d57a98ccd0b4489003473979da8f5a1363ba7a3)
* BLKROTATIONAL - 3.2 (ef00f59c95fe6e002e7c6e3663cdea65e253f4cc)
* BLKZEROOUT - 3.6 (66ba32dc167202c3cf8c86806581a9393ec7f488)
* FIBMAP - <2.6.12 (linux.git epoch)
* FIGETBSZ - <2.6.12 (linux.git epoch)
and when building with latest glibc, we'll see compat definitions
in syscall.c anyway thanks to the previous patch. Thus we can
assume they always exist and remove the conditional checks.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20221004093206.652431-3-berrange@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
GLibc changes prevent us from including linux/fs.h anymore,
and we previously adjusted to this in
commit 3cd3df2a95
Author: Daniel P. Berrangé <berrange@redhat.com>
Date: Tue Aug 2 12:41:34 2022 -0400
linux-user: fix compat with glibc >= 2.36 sys/mount.h
That change required adding compat ioctl definitions on the
QEMU side for any ioctls that we would otherwise obtain
from linux/fs.h. This commit adds more that were initially
missed, due to their usage being conditionalized in QEMU.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20221004093206.652431-2-berrange@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
AT_EXECFD gives access to the binary file even if
it is not readable (only executable).
Moreover it can be opened with flags and mode that are not the ones
provided by do_openat() caller.
And it is not available because loader_exec() has closed it.
To avoid that, use only safe_openat() with the exec_path.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220927124357.688536-3-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
If path is /proc/self/exe, use the executable path
provided by exec_path.
Don't use execfd as it is closed by loader_exec() and otherwise
will survive to the exec() syscall and be usable child process.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220927124357.688536-2-laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
In commit 80f0fe3a85 ("linux-user: Fix syscall parameter handling for
MIPS n32") the ABI problem regarding offset64 on MIPS n32 was fixed,
but still some cases remain where the n32 is incorrectly treated as any
other 32-bit ABI that passes 64-bit arguments in pairs of GPRs. Fix by
excluding TARGET_ABI_MIPSN32 from various TARGET_ABI_BITS == 32 checks.
Closes: https://gitlab.com/qemu-project/qemu/-/issues/1238
Signed-off-by: WANG Xuerui <xen0n@gentoo.org>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Andreas K. Hüttel <dilfridge@gentoo.org>
Cc: Joshua Kinard <kumba@gentoo.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Tested-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Tested-by: Andreas K. Huettel <dilfridge@gentoo.org>
Message-Id: <20221006085500.290341-1-xen0n@gentoo.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Previously the 32-bit version was incorrectly chosen, leading to funny
but incorrect output from e.g. df(1). Simply select the version
corresponding to the 64-bit asm-generic definition.
For reference, this program should produce the same output no matter
natively compiled or not, for loongarch64 or not:
```c
#include <stdio.h>
#include <sys/statfs.h>
int main(int argc, const char *argv[])
{
struct statfs b;
if (statfs(argv[0], &b))
return 1;
printf("f_type = 0x%lx\n", b.f_type);
printf("f_bsize = %ld\n", b.f_bsize);
printf("f_blocks = %ld\n", b.f_blocks);
printf("f_bfree = %ld\n", b.f_bfree);
printf("f_bavail = %ld\n", b.f_bavail);
return 0;
}
// Example output on my amd64 box, with the test binary residing on a
// btrfs partition.
// Native and emulated output after the fix:
//
// f_type = 0x9123683e
// f_bsize = 4096
// f_blocks = 268435456
// f_bfree = 168406890
// f_bavail = 168355058
// Output before the fix, note the messed layout:
//
// f_type = 0x10009123683e
// f_bsize = 723302085239504896
// f_blocks = 168355058
// f_bfree = 2250817541779750912
// f_bavail = 1099229433104
```
Fixes: 1f63019632 ("linux-user: Add LoongArch syscall support")
Signed-off-by: WANG Xuerui <xen0n@gentoo.org>
Cc: Song Gao <gaosong@loongson.cn>
Cc: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Cc: Andreas K. Hüttel <dilfridge@gentoo.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Andreas K. Huettel <dilfridge@gentoo.org>
Message-Id: <20221006100710.427252-1-xen0n@gentoo.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Add support for saving/restoring extended save states when signals
are delivered. This allows using AVX, MPX or PKRU registers in
signal handlers.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linux can use FXSAVE to save/restore XMM registers even on 32-bit
systems. This requires some care in order to keep the FXSAVE area
aligned to 16 bytes; for this reason, get_sigframe is changed to
pass the offset into the FXSAVE area rather than the full frame
size.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
