Casting to a union type is a gcc (and clang) extension. Other compilers
might not support it. This is not a problem today, but the type casts
can be removed easily. Smatch now no longer complains like before:
linux-user/syscall.c:3190:18: warning: cast to non-scalar
linux-user/syscall.c:7348:44: warning: cast to non-scalar
Cc: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer,
for two reasons. One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.
This commit only touches allocations with size arguments of the form
sizeof(T). Same Coccinelle semantic patch as in commit b45c03f.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This should help clarify the purpose of the function that returns
the host system's CPU cycle count.
Signed-off-by: Christopher Covington <cov@codeaurora.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
ppc portion
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Notice raise and bpt, decoding the constants embedded in the
nop addil instruction in the x0 slot.
[rth: Generalize TILEGX_EXCP_OPCODE_ILL to TILEGX_EXCP_SIGNAL.
Drop validation of signal values.]
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Message-Id: <1443243635-4886-1-git-send-email-gang.chen.5i5j@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
[rth: Remove the spreg[EX1] handling, as it's irrelevant to user-mode.]
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Message-Id: <1443312618-13641-1-git-send-email-gang.chen.5i5j@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
They content several new macro members, also contents TARGET_N*.
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Message-Id: <1443240605-2924-1-git-send-email-gang.chen.5i5j@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
All error conditions that target_mprotect checks are also checked
by target_mmap. EACCESS cannot happen because we are just removing
PROT_WRITE. ENOMEM should not happen because we are modifying a
whole VMA (and we have bigger problems anyway if it happens).
Fixes a Coverity false positive, where Coverity complains about
target_mprotect's return value being passed to tb_invalidate_phys_range.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
qemu has already considered about some targets may have no traditional
signals. And openrisc's setup_frame() is dummy, but it can be supported
by setup_rt_frame().
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Under Alpha host, EAGAIN is redefined to 35, so it need be remapped too.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This patch allows to run example given by open_by_handle_at(2):
The following shell session demonstrates the use of these two programs:
$ echo 'Can you please think about it?' > cecilia.txt
$ ./t_name_to_handle_at cecilia.txt > fh
$ ./t_open_by_handle_at < fh
open_by_handle_at: Operation not permitted
$ sudo ./t_open_by_handle_at < fh # Need CAP_SYS_ADMIN
Read 31 bytes
$ rm cecilia.txt
Now we delete and (quickly) re-create the file so that it has the same
content and (by chance) the same inode.[...]
$ stat --printf="%i\n" cecilia.txt # Display inode number
4072121
$ rm cecilia.txt
$ echo 'Can you please think about it?' > cecilia.txt
$ stat --printf="%i\n" cecilia.txt # Check inode number
4072121
$ sudo ./t_open_by_handle_at < fh
open_by_handle_at: Stale NFS file handle
See the man page for source code.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Whilst calls to do_fork() are wrapped in get_errno() this does not
translate return values.
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>
Currently, __target_cmsg_nxthdr compares a pointer derived from
target_cmsg against the msg_control field of target_msgh (through
subtraction). This failed for me when emulating i386 code under x86_64,
because pointers in the host address space and pointers in the guest
address space were not the same. This patch passes the initial value of
target_cmsg into __target_cmsg_nxthdr.
I found and fixed two more related bugs:
- __target_cmsg_nxthdr now returns the new cmsg pointer instead of the
old one.
- tgt_space (in host_to_target_cmsg) doesn't count "sizeof (struct
target_cmsghdr)" twice anymore.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Instead of creating a temporary copy for the whole environment and
the arguments, directly copy everything to the target stack.
For this to work, we have to change the order of stack creation and
copying the arguments.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The system mode binaries provide a similar alias
and it makes common options like --version and --help
work as expected.
Signed-off-by: Meador Inge <meadori@codesourcery.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
As suggested by Laurent, use EXIT_SUCCESS and EXIT_FAILURE from
stdlib.h instead of numeric values.
Cc: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This patch adds better support for diagnosing option
parser errors. The previous implementation just printed
the usage text and exited when a bad option or argument
was found. This made it very difficult to determine why
the usage was being displayed and it was doubly confusing
for cases like '--help' (it wasn't clear that --help was
actually an error).
Signed-off-by: Meador Inge <meadori@codesourcery.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This option is already available on the system mode
binaries. It would be better if long options were
supported (i.e. --help), but this is okay for now.
Signed-off-by: Meador Inge <meadori@codesourcery.com>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Rename ELF_MACHINE to be PPC specific. This is used as-is by the
various PPC bootloaders and is locally defined to ELF_MACHINE in linux
user in PPC specific ifdeffery.
This removes another architecture specific definition from the global
namespace (as desired by multi-arch).
Cc: Alexander Graf <agraf@suse.de>
Cc: qemu-ppc@nongnu.org
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-By: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The only generic code relying on this is linux-user. Linux user
already has a lot of #ifdef TARGET_ customisation so instead, define
ELF_ARCH as either EM_ARM or EM_AARCH64 appropriately.
The armv7m bootloader can just pass EM_ARM directly, as that
is architecture specific code. Note that arm_boot already has its own
logic selecting an arm specific elf machine so this makes V7M more
consistent with arm_boot.
This removes another architecture specific definition from the global
namespace.
Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-By: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For many arch's this macro is defined as the predicatable behaviour
of checking the argument for eqaulity against ELF_ARCH. Provide a
default define as such, so only archs with special handling (usually
allowing multiple EM values) need to provide a def.
Arches that do any of:
1: provide this def exactly the same way as the new default
(alpha, x86_64)
2: check against ELF_MACHINE while defining ELF_ARCH == ELF_MACHINE
(arm, aarch64)
3: check against EM_FOO directly while defining ELF_ARCH == EM_FOO
(unicore32, sparc32, ppc32, mips, openrisc, sh4, cris, m86k)
have their elf_check_arch removed as the default will provide the
correct behaviour.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-By: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In most (but not all) cases, ELF_MACHINE and ELF_ARCH are safely the
same. Default ELF_MACHINE to ELF_ARCH. This makes defining ELF_MACHINE
optional for target-*/cpu.h when they are known to match.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-By: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We are setting SRR0 to the instruction before the one causing the
unaligned exception. A quick testcase:
. = 0x100
.globl _start
_start:
/* Cause a 0x600 */
li 3,0x1
stwcx. 3,0,3
1: b 1b
. = 0x600
1: b 1b
Built into something we can load as a BIOS image:
gcc -mbig -c test.S
ld -EB -Ttext 0x0 -o test test.o
objcopy -O binary test test.bin
Run with:
qemu-system-ppc64 -nographic -bios test.bin
Shows an incorrect SRR0 (points at the li):
SRR0 0000000000000100
With the patch we get the correct SRR0:
SRR0 0000000000000104
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Some of architectures (e.g. tilegx), several syscall macros are not
supported, so switch them.
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <BLU436-SMTP457D6FC9B2B9BA87AEB22CB9660@phx.gbl>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Add main working flow feature, system call processing feature, and elf64
tilegx binary loading feature, based on Linux kernel tilegx 64-bit
implementation.
[rth: Moved all of the implementation of atomic instructions to a later patch.]
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <BLU436-SMTP938552D42808AA60634582B9660@phx.gbl>
Signed-off-by: Richard Henderson <rth@twiddle.net>
They are based on Linux kernel tilegx architecture for 64 bit binary,
and also based on tilegx ABI reference document, and also reference from
other targets implementations.
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <BLU436-SMTP2508945F92945BB525605A3B9660@phx.gbl>
Signed-off-by: Richard Henderson <rth@twiddle.net>
* qemu_mutex_lock_iothread "No such process" fix
* cutils: qemu_strto* wrappers
* iohandler.c simplification
* Many other fixes and misc patches.
And some MTTCG work (with Emilio's fixes squashed):
* Signal-free TCG kick
* Removing spinlock in favor of QemuMutex
* User-mode emulation multi-threading fixes/docs
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
iQEcBAABCAAGBQJV8Tk7AAoJEL/70l94x66Ds3QH/3bi0RRR2NtKIXAQrGo5tfuD
NPMu1K5Hy+/26AC6mEVNRh4kh7dPH5E4NnDGbxet1+osvmpjxAjc2JrxEybhHD0j
fkpzqynuBN6cA2Gu5GUNoKzxxTmi2RrEYigWDZqCftRXBeO2Hsr1etxJh9UoZw5H
dgpU3j/n0Q8s08jUJ1o789knZI/ckwL4oXK4u2KhSC7ZTCWhJT7Qr7c0JmiKReaF
JEYAsKkQhICVKRVmC8NxML8U58O8maBjQ62UN6nQpVaQd0Yo/6cstFTZsRrHMHL3
7A2Tyg862cMvp+1DOX3Bk02yXA+nxnzLF8kUe0rYo6llqDBDStzqyn1j9R0qeqA=
=nB06
-----END PGP SIGNATURE-----
Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging
* Support for jemalloc
* qemu_mutex_lock_iothread "No such process" fix
* cutils: qemu_strto* wrappers
* iohandler.c simplification
* Many other fixes and misc patches.
And some MTTCG work (with Emilio's fixes squashed):
* Signal-free TCG kick
* Removing spinlock in favor of QemuMutex
* User-mode emulation multi-threading fixes/docs
# gpg: Signature made Thu 10 Sep 2015 09:03:07 BST using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>"
* remotes/bonzini/tags/for-upstream: (44 commits)
cutils: work around platform differences in strto{l,ul,ll,ull}
cpu-exec: fix lock hierarchy for user-mode emulation
exec: make mmap_lock/mmap_unlock globally available
tcg: comment on which functions have to be called with mmap_lock held
tcg: add memory barriers in page_find_alloc accesses
remove unused spinlock.
replace spinlock by QemuMutex.
cpus: remove tcg_halt_cond and tcg_cpu_thread globals
cpus: protect work list with work_mutex
scripts/dump-guest-memory.py: fix after RAMBlock change
configure: Add support for jemalloc
add macro file for coccinelle
configure: factor out adding disas configure
vhost-scsi: fix wrong vhost-scsi firmware path
checkpatch: remove tests that are not relevant outside the kernel
checkpatch: adapt some tests to QEMU
CODING_STYLE: update mixed declaration rules
qmp: Add example usage of strto*l() qemu wrapper
cutils: Add qemu_strtoull() wrapper
cutils: Add qemu_strtoll() wrapper
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Warnings from the Sparse static analysis tool:
linux-user/main.c:40:12: warning:
symbol 'filename' was not declared. Should it be static?
linux-user/main.c:41:12: warning:
symbol 'argv0' was not declared. Should it be static?
linux-user/main.c:42:5: warning:
symbol 'gdbstub_port' was not declared. Should it be static?
linux-user/main.c:43:11: warning:
symbol 'envlist' was not declared. Should it be static?
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
A number of files were including assert.h but not using any
of the functions it provides
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Many source files have doubled words (eg "the the", "to to",
and so on). Most of these can simply be removed, but a couple
were actual mis-spellings (eg "to to" instead of "to do").
There was even one triple word score "to to to" :-)
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
There is some iffy lock hierarchy going on in translate-all.c. To
fix it, we need to take the mmap_lock in cpu-exec.c. Make the
functions globally available.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
spinlock is only used in two cases:
* cpu-exec.c: to protect TranslationBlock
* mem_helper.c: for lock helper in target-i386 (which seems broken).
It's a pthread_mutex_t in user-mode, so we can use QemuMutex directly,
with an #ifdef. The #ifdef will be removed when multithreaded TCG
will need the mutex as well.
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Message-Id: <1439220437-23957-5-git-send-email-fred.konrad@greensocs.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
[Merge Emilio G. Cota's patch to remove volatile. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
For the A64 instruction set, the semihosting call instruction
is 'HLT 0xf000'. Wire this up to call do_arm_semihosting()
if semihosting is enabled.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Christopher Covington <christopher.covington@linaro.org>
Tested-by: Christopher Covington <cov@codeaurora.org>
Message-id: 1439483745-28752-10-git-send-email-peter.maydell@linaro.org
As we have removed CONFIG_USE_GUEST_BASE, we always use a guest base
and the macros GUEST_BASE and RESERVED_VA become useless: replace
them by their values.
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <1440420834-8388-1-git-send-email-laurent@vivier.eu>
Signed-off-by: Richard Henderson <rth@twiddle.net>
All tcg host architectures now support the guest base and as
there is no real performance lost, it can be always enabled.
Anyway, guest base use can be disabled lively by setting guest
base to 0.
CONFIG_USE_GUEST_BASE is defined as (USE_GUEST_BASE && USER_ONLY),
it should have to be replaced by CONFIG_USER_ONLY in non CONFIG_USER_ONLY
parts, but as some other parts are using !CONFIG_SOFTMMU I have chosen to
use !CONFIG_SOFTMMU instead.
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <1440373328-9788-2-git-send-email-laurent@vivier.eu>
Signed-off-by: Richard Henderson <rth@twiddle.net>
For the MIPS N64 ABI when QEMU reads the break/trap instruction so that
it can inspect the break/trap code it reads 8 rather than 4 bytes
which means it finds the code field from the instruction after the
break/trap instruction. This then causes the break/trap handling
code to fail because it does not understand the code number.
The fix forces QEMU to always read 4 bytes of instruction data rather
than deciding how much to read based on the ABI.
Signed-off-by: Andrew Bennett <andrew.bennett@imgtec.com>
Reviewed-by: Leon Alrae <leon.alrae@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Remove un-needed usages of ENV_GET_CPU() by converting the APIs to use
CPUState pointers and retrieving the env_ptr as minimally needed.
Scripted conversion for target-* change:
for I in target-*/cpu.h; do
sed -i \
's/\(^int cpu_[^_]*_exec(\)[^ ][^ ]* \*s);$/\1CPUState *cpu);/' \
$I;
done
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
All callsites to this function navigate the cpu->env_ptr only for the
function to take the env ptr back to the original cpu ptr. Change the
function to just pass in the CPU pointer instead. Removes a core code
usage of ENV_GET_CPU() (in gdbstub.c).
Cc: Riku Voipio <riku.voipio@iki.fi>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
All of the core-code usages of this API have the cpu pointer handy so
pass it in. There are only 3 architecture specific usages (2 of which
are commented out) which can just use ENV_GET_CPU() locally to get the
cpu pointer. The reduces core code usage of the CPU env, which brings
us closer to common-obj'ing these core files.
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
In qemu-linux-user, when calling gethostbyname2(),
it was hanging in .__res_nmkquery.
(gdb) bt
0 in .__res_nmkquery () from /lib64/libresolv.so.2
1 in .__libc_res_nquery () from /lib64/libresolv.so.2
2 in .__libc_res_nsearch () from /lib64/libresolv.so.2
3 in ._nss_dns_gethostbyname3_r () from /lib64/libnss_dns.so.2
4 in ._nss_dns_gethostbyname2_r () from /lib64/libnss_dns.so.2
5 in .gethostbyname2_r () from /lib64/libc.so.6
6 in .gethostbyname2 () from /lib64/libc.so.6
.__res_nmkquery() is:
...
do { RANDOM_BITS (randombits); } while ((randombits & 0xffff) == 0);
...
<.__res_nmkquery+112>: mftbl r11
<.__res_nmkquery+116>: clrlwi r10,r11,16
<.__res_nmkquery+120>: cmpwi cr7,r10,0
<.__res_nmkquery+124>: beq cr7,<.__res_nmkquery+112>
but as mftbl (Move From Time Base Lower) is not implemented,
r11 is always 0, so we have an infinite loop.
This patch fills the Time Base register with cpu_get_real_ticks().
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Alexander Graf <agraf@suse.de>
When executing a 64bit target chroot on 64bit host,
the ioctl() command can mismatch.
It seems the previous commit doesn't solve the problem in
my case:
9c6bf9c7 linux-user: Fix ioctl cmd type mismatch on 64-bit targets
For example, a ppc64 chroot on an x86_64 host:
bash-4.3# ls
Unsupported ioctl: cmd=0x80087467
Unsupported ioctl: cmd=0x802c7415
The origin of the problem is in syscall.c:do_ioctl().
static abi_long do_ioctl(int fd, abi_long cmd, abi_long arg)
In this case (ppc64) abi_long is long (on the x86_64), and
cmd = 0x0000000080087467
then
if (ie->target_cmd == cmd)
target_cmd is int, so target_cmd = 0x80087467
and to compare an int with a long, the sign is extended to 64bit,
so the comparison is:
if (0xffffffff80087467 == 0x0000000080087467)
which doesn't match whereas it should.
This patch uses int in the case of the target command type
instead of abi_long.
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
When a thread is spawned, cpu_copy re-initializes
the bp & wp lists of current thread, instead of the ones
of the new thread.
The effect is that breakpoints are no longer hit.
Signed-off-by: Thierry Bultel <thierry.bultel@basystemes.fr>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The target payloads in cmsg conversions may not have the alignment
required by the host. Using the get_user and put_user functions is
the easiest way to handle this and also do the byte-swapping we
require.
(Note that prior to this commit target_to_host_cmsg was incorrectly
using __put_user() rather than __get_user() for the SCM_CREDENTIALS
conversion, which meant it wasn't getting the benefit of the
misalignment handling.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The previous code for handling payload length when converting
cmsg structures from host to target had a number of problems:
* we required the msg->msg_controllen to declare the buffer
to have enough space for final trailing padding (we were
checking against CMSG_SPACE), whereas the kernel does not
require this, and common userspace code assumes this. (In
particular, glibc's "try to talk to nscd" code that it will
run on startup will receive a cmsg with a 4 byte payload and
only allocate 4 bytes for it, which was causing us to do
the wrong thing on architectures that need 8-alignment.)
* we weren't correctly handling the fact that the SO_TIMESTAMP
payload may be larger for the target than the host
* we weren't marking the messages with MSG_CTRUNC when we did
need to truncate a message that wasn't truncated by the host,
but were instead logging a QEMU message; since truncation is
always the result of a guest giving us an insufficiently
sized buffer, we should report it to the guest as the kernel
does and don't log anything
Rewrite the parts of the function that deal with length to
fix these issues, and add a comment in target_to_host_cmsg
to explain why the overflow logging it does is a QEMU bug,
not a guest issue.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Stefan Weil