We're about to start validating PAGE_EXEC, which means
that we've got to mark the commpage executable. We had
been placing the commpage outside of reserved_va, which
was incorrect and lead to an abort.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Perform the cleanup in the FIXME comment in common_semi_gdb_syscall.
Do not modify guest registers until the syscall is complete,
which in the gdbstub case is asynchronous.
In the synchronous non-gdbstub case, use common_semi_set_ret
to set the result. Merge set_swi_errno into common_semi_cb.
Rely on the latter for combined return value / errno setting.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Bool is a more appropriate type for this value.
Adjust the assignments to use true/false.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Convert the TARGET_WORDS_BIGENDIAN macro, similarly to what was done
with HOST_BIG_ENDIAN. The new TARGET_BIG_ENDIAN macro is either 0 or 1,
and thus should always be defined to prevent misuse.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-8-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace a config-time define with a compile time condition
define (compatible with clang and gcc) that must be declared prior to
its usage. This avoids having a global configure time define, but also
prevents from bad usage, if the config header wasn't included before.
This can help to make some code independent from qemu too.
gcc supports __BYTE_ORDER__ from about 4.6 and clang from 3.2.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[ For the s390x parts I'm involved in ]
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If CONFIG_ATOMIC64, we can use a host cmpxchg and provide
atomicity across processes; otherwise we have no choice but
to continue using start/end_exclusive.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323005839.94327-4-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The existing implementation using start/end_exclusive
does not provide atomicity across processes.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323005839.94327-3-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This fallback syscall was stubbed out.
It would only matter for emulating pre-armv6.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323005839.94327-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Fix a typo in a comment in the arm cpu_loop code.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20220114182535.3804783-1-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Place it next to copy_from/to_user_oabi_flock64, the only users,
inside the existing target-specific ifdef. This leaves only
generic ipc structs in target_structs.h.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220107042600.149852-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Since the prctl constants are supposed to be generic, supply
any that are not provided by the host.
Split out subroutines for PR_GET_FP_MODE, PR_SET_FP_MODE,
PR_GET_VL, PR_SET_VL, PR_RESET_KEYS, PR_SET_TAGGED_ADDR_CTRL,
PR_GET_TAGGED_ADDR_CTRL. Return EINVAL for guests that do
not support these options rather than pass them on to the host.
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211227150127.2659293-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
TARGET_MINSIGSTKSZ has been defined in generic/signal.h
or target_signal.h, We don't need to define it again.
Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1637893388-10282-3-git-send-email-gaosong@loongson.cn>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This value is fully internal to qemu, and so is not a TARGET define.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This value is fully internal to qemu, and so is not a TARGET define.
We use this as an extra marker for both host and target errno.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Because of the complexity of setting ESR, re-use the existing
arm_cpu_do_unaligned_access function. This means we have to
handle the exception ourselves in cpu_loop, transforming it
to the appropriate signal.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Mirror what the kernel does in arch/arm/kernel/signal.h,
using the old sigframe struct in the rt sigframe struct.
Update the trampoline code to match the kernel: this uses
sp-relative accesses rather than pc-relative.
Copy the code into frame->retcode from the trampoline page.
This minimises the different cases wrt arm vs thumb vs fdpic.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210929130553.121567-6-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Since we no longer support "v1", there's no need to distinguish "v2".
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210929130553.121567-5-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Version 2 signal frames are used from 2.6.12 and since cbc14e6f28,
we have set UNAME_MINIMUM_RELEASE to 2.6.32.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210929130553.121567-4-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Use the new force_sig_fault() function instead of setting up
a target_siginfo_t and calling queue_signal().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210813131809.28655-7-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
In the Arm target code, when the fpa11 emulation code tells us we
need to send the guest a SIGFPE, we do this with queue_signal(), but
we are using the wrong si_type, and we aren't setting the _sifields
union members corresponding to either the si_type we are using or the
si_type we should be using.
As the existing comment notes, the kernel code for this calls the old
send_sig() function to deliver the signal. This eventually results
in the kernel's signal handling code fabricating a siginfo_t with a
SI_KERNEL code and a zero pid and uid. For QEMU this means we need
to use QEMU_SI_KILL. We already have a function for that:
force_sig() sets up the whole target_siginfo_t the way we need it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210813131809.28655-4-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
When generating a TRAP_BRKPT SIGTRAP, set the siginfo_t addr field
to the PC where the breakpoint/singlestep trap occurred; this is
what the kernel does for this signal for this architecture.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210813131809.28655-3-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
qemu.h is included in various non-linux-user files (which
mostly want the TaskState struct and the functions for
doing usermode access to guest addresses like lock_user(),
unlock_user(), get_user*(), etc).
Split out the parts that are only used in linux-user itself
into a new user-internals.h. This leaves qemu.h with basically
three things:
* the definition of the TaskState struct
* the user-access functions and macros
* do_brk()
all of which are needed by code outside linux-user that
includes qemu.h.
The addition of all the extra #include lines was done with
sed -i '/include.*qemu\.h/a #include "user-internals.h"' $(git grep -l 'include.*qemu\.h' linux-user)
(and then undoing the change to fpa11.h).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-8-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Split the signal related prototypes into the existing header file
signal-common.h, and include it in those places that now require it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210908154405.15417-4-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Currently we rely on all the callsites of cpsr_write() to rebuild the
cached hflags if they change one of the CPSR bits which we use as a
TB flag and cache in hflags. This is a bit awkward when we want to
change the set of CPSR bits that we cache, because it means we need
to re-audit all the cpsr_write() callsites to see which flags they
are writing and whether they now need to rebuild the hflags.
Switch instead to making cpsr_write() call arm_rebuild_hflags()
itself if one of the bits being changed is a cached bit.
We don't do the rebuild for the CPSRWriteRaw write type, because that
kind of write is generally doing something special anyway. For the
CPSRWriteRaw callsites in the KVM code and inbound migration we
definitely don't want to recalculate the hflags; the callsites in
boot.c and arm-powerctl.c have to do a rebuild-hflags call themselves
anyway because of other CPU state changes they make.
This allows us to drop explicit arm_rebuild_hflags() calls in a
couple of places where the only reason we needed to call it was the
CPSR write.
This fixes a bug where we were incorrectly failing to rebuild hflags
in the code path for a gdbstub write to CPSR, which meant that you
could make QEMU assert by breaking into a running guest, altering the
CPSR to change the value of, for example, CPSR.E, and then
continuing.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210817201843.3829-1-peter.maydell@linaro.org
We want to access the target errno indepently of the rest of the
linux-user code. Move the header containing the generic errno
definitions ('errno_defs.h') to 'generic/target_errno_defs.h',
create a new 'target_errno_defs.h' in each target which itself
includes 'generic/target_errno_defs.h'.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210708170550.1846343-4-f4bug@amsat.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Use an enumeration instead of raw 32/64/80 values.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In most cases we were already passing get_sp_from_cpustate
directly to the function. In other cases, we were passing
a local variable which already contained the same value.
In the rest of the cases, we were passing the stack pointer
out of env directly.
Reviewed by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210426025334.1168495-5-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Note that target_restore_altstack uses the host memory
pointer that we have already verified, so TARGET_EFAULT
is not a possible return value.
Note that using -EFAULT was a bug.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210426025334.1168495-3-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Use bit masking instead of an if tree.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210423165413.338259-5-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
There is no such decoding in linux/arch/arm/nwfpe/fpmodule.c.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210423165413.338259-4-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Pull out the fpa11 emulation to a helper function.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210423165413.338259-2-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
We want to move the semihosting code out of hw/ in the next patch.
This patch contains the mechanical steps, created using:
$ git mv include/hw/semihosting/ include/
$ sed -i s,hw/semihosting,semihosting, $(git grep -l hw/semihosting)
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210226131356.3964782-2-f4bug@amsat.org>
Message-Id: <20210305135451.15427-2-alex.bennee@linaro.org>
The public API is now defined in
hw/semihosting/common-semi.h. do_common_semihosting takes CPUState *
instead of CPUARMState *. All internal functions have been renamed
common_semi_ instead of arm_semi_ or arm_. Aside from the API change,
there are no functional changes in this patch.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210107170717.2098982-3-keithp@keithp.com>
Message-Id: <20210108224256.2321-14-alex.bennee@linaro.org>
This commit renames two files which provide ARM semihosting support so
that they can be shared by other architectures:
1. target/arm/arm-semi.c -> hw/semihosting/common-semi.c
2. linux-user/arm/semihost.c -> linux-user/semihost.c
The build system was modified use a new config variable,
CONFIG_ARM_COMPATIBLE_SEMIHOSTING, which has been added to the ARM
softmmu and linux-user default configs. The contents of the source
files has not been changed in this patch.
Signed-off-by: Keith Packard <keithp@keithp.com>
[AJB: rename arm-compat-semi, select SEMIHOSTING]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210107170717.2098982-2-keithp@keithp.com>
Message-Id: <20210108224256.2321-13-alex.bennee@linaro.org>
The Linux kernel doesn't use the official bkpt insn for breakpoints;
instead it uses three instructions in the guaranteed-to-UNDEF space,
and generates SIGTRAP for these rather than the SIGILL that most
UNDEF insns generate:
https://elixir.bootlin.com/linux/v5.9.8/source/arch/arm/kernel/ptrace.c#L197
Make QEMU treat these insns specially too. The main benefit of this
is that if you're running a debugger on a guest program that runs
into a GCC __builtin_trap() or LLVM "trap because execution should
never reach here" then you'll get the expected signal rather than a
SIGILL.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201117155634.6924-1-peter.maydell@linaro.org
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.
Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Message-Id: <20201023122455.19417-1-chetan4windows@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Some platforms used the wrong definition of stack_t where the flags and
size fields were swapped or where the flags field had type ulong instead
of int.
Due to the presence of padding space in the structure and the prevalence
of little-endian machines this problem went unnoticed for a long time.
The type definitions have been cross-checked with the ones defined in
the Linux kernel v5.9, plus some older versions for a few architecture
that have been removed and Xilinx's kernel fork for NiosII [1].
The bsd-user headers remain unchanged as I don't know if they are wrong
or not.
[1] https://github.com/Xilinx/linux-xlnx/blob/master/arch/nios2/include/uapi/asm/signal.h
Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <e9d47692-ee92-009f-6007-0abc3f502b97@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This patch introduces a generic 'termbits.h' file for following
archs: 'aarch64', 'arm', 'i386, 'm68k', 'microblaze', 'nios2',
'openrisc', 'riscv', 's390x', 'x86_64'.
Since all of these archs have the same termios flag values and
same ioctl_tty numbers, there is no need for a separate 'termbits.h'
file for each one of them. For that reason one generic 'termbits.h'
file was added for all of them and an '#include' directive was
added for this generic file in every arch 'termbits.h' file.
Also, some of the flag values that were missing were added in this
generic file so that it matches the generic 'termibts.h' and 'ioctls.h'
files from the kernel: 'asm-generic/termbits.h' and 'asm-generic/ioctls.h'.
Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200723210233.349690-2-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This patch implements strace argument printing functionality for following syscalls:
* mlock, munlock, mlockall, munlockall - lock and unlock memory
int mlock(const void *addr, size_t len)
int munlock(const void *addr, size_t len)
int mlockall(int flags)
int munlockall(void)
man page: https://man7.org/linux/man-pages/man2/mlock.2.html
Implementation notes:
Syscall mlockall() takes an argument that is composed of predefined values
which represent flags that determine the type of locking operation that is
to be performed. For that reason, a printing function "print_mlockall" was
stated in file "strace.list". This printing function uses an already existing
function "print_flags()" to print the "flags" argument. These flags are stated
inside an array "mlockall_flags" that contains values of type "struct flags".
These values are instantiated using an existing macro "FLAG_TARGET()" that
crates aproppriate target flag values based on those defined in files
'/target_syscall.h'. These target flag values were changed from
"TARGET_MLOCKALL_MCL*" to "TARGET_MCL_*" so that they can be aproppriately set
and recognised in "strace.c" with "FLAG_TARGET()". Value for "MCL_ONFAULT"
was added in this patch. This value was also added in "syscall.c" in function
"target_to_host_mlockall_arg()". Because this flag value was added in kernel
version 4.4, it is enwrapped in an #ifdef directive (both in "syscall.c" and
in "strace.c") as to support older kernel versions.
The other syscalls have only primitive argument types, so the
rest of the implementation was handled by stating an appropriate
printing format in file "strace.list". Syscall mlock2() is not implemented in
"syscall.c" and thus it's argument printing is not implemented in this patch.
Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200811164553.27713-4-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The most interesting or most complicated part here is the syscall_nr.h
generators. In order to keep the generation logic all in meson.build,
I am adding to config_target the name of the .tbl file, and making the
generated file syscall<SUFFIX>_nr.h for input file syscall<SUFFIX>.tbl.
For architectures where the input file is not named syscall_nr.tbl,
syscall_nr.h has to be a source file; it's just a forwarder for x86
(i386/x86_64), while for MIPS64 it chooses between N32 and N64 ABIs.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The Arm signal-handling code has some parts ifdeffed with a
TARGET_CONFIG_CPU_32, which is always defined. This is a leftover
from when this code's structure was based on the Linux kernel
signal handling code, where it was intended to support 26-bit
Arm CPUs. The kernel dropped its CONFIG_CPU_32 in kernel commit
4da8b8208eded0ba21e3 in 2009.
QEMU has never had 26-bit CPU support and is unlikely to ever
add it; we certainly aren't going to support 26-bit Linux
binaries via linux-user mode. The ifdef is just unhelpful
noise, so remove it entirely.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200518143014.20689-1-peter.maydell@linaro.org
This fixes signal handlers running with the wrong endianness if the
interrupted code used SETEND to dynamically switch endianness.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200511131117.2486486-1-amanieu@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Using the MSR instruction to write to CPSR.E is deprecated, but it is
required to work from any mode including unprivileged code. We were
incorrectly forbidding usermode code from writing it because
CPSR_USER did not include the CPSR_E bit.
We use CPSR_USER in only three places:
* as the mask of what to allow userspace MSR to write to CPSR
* when deciding what bits a linux-user signal-return should be
able to write from the sigcontext structure
* in target_user_copy_regs() when we set up the initial
registers for the linux-user process
In the first two cases not being able to update CPSR.E is a bug, and
in the third case it doesn't matter because CPSR.E is always 0 there.
So we can fix both bugs by adding CPSR_E to CPSR_USER.
Because the cpsr_write() in restore_sigcontext() is now changing
a CPSR bit which is cached in hflags, we need to add an
arm_rebuild_hflags() call there; the callsite in
target_user_copy_regs() was already rebuilding hflags for other
reasons.
(The recommended way to change CPSR.E is to use the 'SETEND'
instruction, which we do correctly allow from usermode code.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200518142801.20503-1-peter.maydell@linaro.org
