FEAT_SME2 adds the ZT0 register, whose contents may need to be
preserved and restored on signal handler entry and exit. This is
done with a new ZT_MAGIC record. We forgot to implement support for
this in our linux-user code before enabling the SME2p1 emulation,
which meant that a signal handler using SME would corrupt the ZT0
register value, and code that attempted to unwind an exception from
inside a signal handler would not work.
Add the missing record handling.
Fixes: 7b1613a102 ("target/arm: Enable FEAT_SME2p1 on -cpu max")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250725175510.3864231-4-peter.maydell@linaro.org>
FEAT_SME adds the TPIDR2 userspace-accessible system register, which
is used as part of the procedure calling standard's lazy saving
scheme for the ZA registers:
https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#66the-za-lazy-saving-scheme
The Linux kernel has a signal frame record for saving
and restoring this value when calling signal handlers, but
we forgot to implement this. The result is that code which
tries to unwind an exception out of a signal handler will
not work correctly.
Add support for the missing record.
Cc: qemu-stable@nongnu.org
Fixes: 78011586b9 ("target/arm: Enable SME for user-only")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250725175510.3864231-3-peter.maydell@linaro.org>
A recent change to the kernel (Linux commit b376108e1f88
"arm64/fpsimd: signal: Clear TPIDR2 when delivering signals") updated
the signal-handler entry code to always clear TPIDR2_EL0.
This is necessary for the userspace ZA lazy saving scheme to work
correctly when unwinding exceptions across a signal boundary.
(For the essay-length description of the incorrect behaviour and
why this is the correct fix, see the commit message for the
kernel commit.)
Make QEMU also clear TPIDR2_EL0 on signal entry, applying the
equivalent bugfix to our implementation.
Note that getting this unwinding to work correctly also requires
changes to the userspace code, e.g. as implemented in gcc in
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=b5ffc8e75a8
This change is technically an ABI change; from the kernel's
point of view SME was never enabled (it was hidden behind
CONFIG_BROKEN) before the change. From QEMU's point of view
our SME-related signal handling was broken anyway as we weren't
saving and restoring TPIDR2_EL0.
Cc: qemu-stable@nongnu.org
Fixes: 78011586b9 ("target/arm: Enable SME for user-only")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250725175510.3864231-2-peter.maydell@linaro.org>
The whole ZA state will also contain ZT0.
Make things easier in aarch64_set_svcr to zero both
by wrapping them in a common structure.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250704142112.1018902-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Move tswap_siginfo from target code to handle_pending_signal. This will
allow some cleanups and having the siginfo ready to be used in gdbstub.
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240309030901.1726211-3-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
The feature test functions isar_feature_*() now take up nearly
a thousand lines in target/arm/cpu.h. This header file is included
by a lot of source files, most of which don't need these functions.
Move the feature test functions to their own header file.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20231024163510.2972081-2-peter.maydell@linaro.org
Set the SM bit in the SVE record on signal delivery, create the ZA record.
Restore SM and ZA state according to the records present on return.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-41-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Move the checks out of the parsing loop and into the
restore function. This more closely mirrors the code
structure in the kernel, and is slightly clearer.
Reject rather than silently skip incorrect VL and SVE record sizes,
bringing our checks in to line with those the kernel does.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-40-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-39-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In parse_user_sigframe, the kernel rejects duplicate sve records,
or records that are smaller than the header. We were silently
allowing these cases to pass, dropping the record.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-38-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Fold the return value setting into the goto, so each
point of failure need not do both.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-37-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Make sure to zero the currently reserved fields.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-36-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add an interface function to extract the digested vector length
rather than the raw zcr_el[1] value. This fixes an incorrect
return from do_prctl_set_vl where we didn't take into account
the set of vector lengths supported by the cpu.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220607203306.657998-3-richard.henderson@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>
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>
Create and record the rt signal trampoline.
Use it when the guest does not use SA_RESTORER.
Reviewed-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: <20210929130553.121567-3-richard.henderson@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>
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>
The kernel sets btype for the signal handler as if for a call.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201021173749.111103-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
I found that there are many spelling errors in the comments of qemu,
so I used the spellcheck tool to check the spelling errors
and finally found some spelling errors in the linux-user folder.
Signed-off-by: zhaolichang <zhaolichang@huawei.com>
Reviewed-by: Alex Bennee <alex.bennee@linaro.org>
Message-Id: <20200917075029.313-7-zhaolichang@huawei.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Cleanup in the boilerplate that each target must define.
Replace arm_env_get_cpu with env_archcpu. The combination
CPU(arm_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20181016223115.24100-8-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
No code change, only move code from signal.c to
aarch64/signal.c, except adding includes and
exporting setup_frame() and setup_rt_frame().
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180424192635.6027-3-laurent@vivier.eu>
Create a signal-common.h for future use by these new files
and use it in the existing signal.c
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180424192635.6027-2-laurent@vivier.eu>
