Unlike A-profile, for M-profile the UDIV and SDIV insns can be
configured to raise an exception on division by zero, using the CCR
DIV_0_TRP bit.
Implement support for setting this bit by making the helper functions
raise the appropriate exception.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210730151636.17254-3-peter.maydell@linaro.org
For M-profile, we weren't reporting alignment faults triggered by the
generic TCG code correctly to the guest. These get passed into
arm_v7m_cpu_do_interrupt() as an EXCP_DATA_ABORT with an A-profile
style exception.fsr value of 1. We didn't check for this, and so
they fell through into the default of "assume this is an MPU fault"
and were reported to the guest as a data access violation MPU fault.
Report these alignment faults as UsageFaults which set the UNALIGNED
bit in the UFSR.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210723162146.5167-4-peter.maydell@linaro.org
In do_v7m_exception_exit(), we perform various checks as part of
performing the exception return. If one of these checks fails, the
architecture requires that we take an appropriate exception on the
existing stackframe. We implement this by calling
v7m_exception_taken() to set up to take the new exception, and then
immediately returning from do_v7m_exception_exit() without proceeding
any further with the unstack-and-exception-return process.
In a couple of checks that are new in v8.1M, we forgot the "return"
statement, with the effect that if bad code in the guest tripped over
these checks we would set up to take a UsageFault exception but then
blunder on trying to also unstack and return from the original
exception, with the probable result that the guest would crash.
Add the missing return statements.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210723162146.5167-3-peter.maydell@linaro.org
For M-profile, unlike A-profile, the low 2 bits of SP are defined to be
RES0H, which is to say that they must be hardwired to zero so that
guest attempts to write non-zero values to them are ignored.
Implement this behaviour by masking out the low bits:
* for writes to r13 by the gdbstub
* for writes to any of the various flavours of SP via MSR
* for writes to r13 via store_reg() in generated code
Note that all the direct uses of cpu_R[] in translate.c are in places
where the register is definitely not r13 (usually because that has
been checked for as an UNDEFINED or UNPREDICTABLE case and handled as
UNDEF).
All the other writes to regs[13] in C code are either:
* A-profile only code
* writes of values we can guarantee to be aligned, such as
- writes of previous-SP-value plus or minus a 4-aligned constant
- writes of the value in an SP limit register (which we already
enforce to be aligned)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210723162146.5167-2-peter.maydell@linaro.org
When MVE is supported, the VPR register has a place on the exception
stack frame in a previously reserved slot just above the FPSCR.
It must also be zeroed in various situations when we invalidate
FPU context.
Update the code which handles the stack frames (exception entry and
exit code, VLLDM, and VLSTM) to save/restore VPR.
Update code which invalidates FP registers (mostly also exception
entry and exit code, but also VSCCLRM and the code in
full_vfp_access_check() that corresponds to the ExecuteFPCheck()
pseudocode) to zero VPR.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210614151007.4545-4-peter.maydell@linaro.org
The sequence cpu_restore_state() + raise_exception() is equivalent to
raise_exception_ra(), so use that instead. (In this case we never
cared about the syndrome value, because M-profile doesn't use the
syndrome; the old code was just written unnecessarily awkwardly.)
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jamie Iles <jamie@nuviainc.com>
[PMM: Retain edited version of comment; rewrite commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When an M-profile CPU is restoring registers from the stack on
exception return, the stack pointer to use is determined based on
bits in the magic exception return type value. We were not getting
this logic entirely correct.
Whether we use one of the Secure stack pointers or one of the
Non-Secure stack pointers depends on the EXCRET.S bit. However,
whether we use the MSP or the PSP then depends on the SPSEL bit in
either the CONTROL_S or CONTROL_NS register. We were incorrectly
selecting MSP vs PSP based on the EXCRET.SPSEL bit.
(In the pseudocode this is in the PopStack() function, which calls
LookUpSp_with_security_mode() which in turn looks at the relevant
CONTROL.SPSEL bit.)
The buggy behaviour wasn't noticeable in most cases, because we write
EXCRET.SPSEL to the CONTROL.SPSEL bit for the S/NS register selected
by EXCRET.ES, so we only do the wrong thing when EXCRET.S and
EXCRET.ES are different. This will happen when secure code takes a
secure exception, which then tail-chains to a non-secure exception
which finally returns to the original secure code.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210520130905.2049-1-peter.maydell@linaro.org
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>
When building with GCC 10.2 configured with --extra-cflags=-Os, we get:
target/arm/m_helper.c: In function ‘arm_v7m_cpu_do_interrupt’:
target/arm/m_helper.c:1811:16: error: ‘restore_s16_s31’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
1811 | if (restore_s16_s31) {
| ^
target/arm/m_helper.c:1350:10: note: ‘restore_s16_s31’ was declared here
1350 | bool restore_s16_s31;
| ^~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Initialize the 'restore_s16_s31' variable to silence the warning.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210119062739.589049-1-f4bug@amsat.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@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>
v8.1M introduces a new TRD flag in the CCR register, which enables
checking for stack frame integrity signatures on SG instructions.
Add the code in the SG insn implementation for the new behaviour.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201119215617.29887-24-peter.maydell@linaro.org
In v8.1M a new exception return check is added which may cause a NOCP
UsageFault (see rule R_XLTP): before we clear s0..s15 and the FPSCR
we must check whether access to CP10 from the Security state of the
returning exception is disabled; if it is then we must take a fault.
(Note that for our implementation CPPWR is always RAZ/WI and so can
never cause CP10 accesses to fail.)
The other v8.1M change to this register-clearing code is that if MVE
is implemented VPR must also be cleared, so add a TODO comment to
that effect.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201119215617.29887-20-peter.maydell@linaro.org
In v8.1M, vector table fetch failures don't set HFSR.FORCED (see rule
R_LLRP). (In previous versions of the architecture this was either
required or IMPDEF.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201119215617.29887-18-peter.maydell@linaro.org
In v8.0M, on exception entry the registers R0-R3, R12, APSR and EPSR
are zeroed for an exception taken to Non-secure state; for an
exception taken to Secure state they become UNKNOWN, and we chose to
leave them at their previous values.
In v8.1M the behaviour is specified more tightly and these registers
are always zeroed regardless of the security state that the exception
targets (see rule R_KPZV). Implement this.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201119215617.29887-17-peter.maydell@linaro.org
In arm_v7m_mmu_idx_for_secstate() we get the 'priv' level to pass to
armv7m_mmu_idx_for_secstate_and_priv() by calling arm_current_el().
This is incorrect when the security state being queried is not the
current one, because arm_current_el() uses the current security state
to determine which of the banked CONTROL.nPRIV bits to look at.
The effect was that if (for instance) Secure state was in privileged
mode but Non-Secure was not then we would return the wrong MMU index.
The only places where we are using this function in a way that could
trigger this bug are for the stack loads during a v8M function-return
and for the instruction fetch of a v8M SG insn.
Fix the bug by expanding out the M-profile version of the
arm_current_el() logic inline so it can use the passed in secstate
rather than env->v7m.secure.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201022164408.13214-1-peter.maydell@linaro.org
We need to check the memattr of a page in order to determine
whether it is Tagged for MTE. Between Stage1 and Stage2,
this becomes simpler if we always collect this data, instead
of occasionally being presented with NULL.
Use the nonnull attribute to allow the compiler to check that
all pointer arguments are non-null.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200626033144.790098-42-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Use this in the places that were checking ARM_FEATURE_VFP, and
are obviously testing for the existance of the register set
as opposed to testing for some particular instruction extension.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200224222232.13807-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Before we introduce blocking semihosting calls we need to ensure we
can restart the system on semi hosting exception. To be able to do
this the EXCP_SEMIHOST operation should be idempotent until it finally
completes. Practically this means ensureing we only update the pc
after the semihosting call has completed.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: Keith Packard <keithp@keithp.com>
According to the PushStack() pseudocode in the armv7m RM,
bit 4 of the LR should be set to NOT(CONTROL.PFCA) when
an FPU is present. Current implementation is doing it for
armv8, but not for armv7. This patch makes the existing
logic applicable to both code paths.
Signed-off-by: Jean-Hugues Deschenes <jean-hugues.deschenes@ossiaco.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Simply moving the non-stub helper_v7m_mrs/msr outside of
!CONFIG_USER_ONLY is not an option, because of all of the
other system-mode helpers that are called.
But we can split out a few subroutines to handle the few
EL0 accessible registers without duplicating code.
Reported-by: Christophe Lyon <christophe.lyon@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191118194916.3670-1-richard.henderson@linaro.org
[PMM: deleted now-redundant comment; added a default case
to switch in v7m_msr helper]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Continue setting, but not relying upon, env->hflags.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191023150057.25731-21-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We do this for other semihosting calls so we might as well do it for
M-profile as well.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190913151845.12582-3-alex.bennee@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Almost a third of its inclusions are actually superfluous. Delete
them. Downgrade two more to qapi/qapi-types-run-state.h, and move one
from char/serial.h to char/serial.c.
hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and
stubs/semihost.c define variables declared in sysemu/sysemu.h without
including it. The compiler is cool with that, but include it anyway.
This doesn't reduce actual use much, as it's still included into
widely included headers. The next commit will tackle that.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-27-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h). It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.
Include qemu/main-loop.h only where it's needed. Touching it now
recompiles only some 1700 objects. For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the
others, they shrink only slightly.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
In the M-profile architecture, when we do a vector table fetch and it
fails, we need to report a HardFault. Whether this is a Secure HF or
a NonSecure HF depends on several things. If AIRCR.BFHFNMINS is 0
then HF is always Secure, because there is no NonSecure HardFault.
Otherwise, the answer depends on whether the 'underlying exception'
(MemManage, BusFault, SecureFault) targets Secure or NonSecure. (In
the pseudocode, this is handled in the Vector() function: the final
exc.isSecure is calculated by looking at the exc.isSecure from the
exception returned from the memory access, not the isSecure input
argument.)
We weren't doing this correctly, because we were looking at
the target security domain of the exception we were trying to
load the vector table entry for. This produces errors of two kinds:
* a load from the NS vector table which hits the "NS access
to S memory" SecureFault should end up as a Secure HardFault,
but we were raising an NS HardFault
* a load from the S vector table which causes a BusFault
should raise an NS HardFault if BFHFNMINS == 1 (because
in that case all BusFaults are NonSecure), but we were raising
a Secure HardFault
Correct the logic.
We also fix a comment error where we claimed that we might
be escalating MemManage to HardFault, and forgot about SecureFault.
(Vector loads can never hit MPU access faults, because they're
always aligned and always use the default address map.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20190705094823.28905-1-peter.maydell@linaro.org
In the various helper functions for v7M/v8M instructions, use
the _ra versions of cpu_stl_data() and friends. Otherwise we
may get wrong behaviour or an assert() due to not being able
to locate the TB if there is an exception on the memory access
or if it performs an IO operation when in icount mode.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190617175317.27557-5-peter.maydell@linaro.org
In preparation for supporting TCG disablement on ARM, we move most
of TCG related v7m/v8m helpers and APIs into their own file.
Note: It is easier to review this commit using the 'histogram'
diff algorithm:
$ git diff --diff-algorithm=histogram ...
or
$ git diff --histogram ...
Suggested-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190702144335.10717-2-philmd@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: updated qapi #include to match recent changes there]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
