xemu/target/i386
Richard Henderson 8929906e21 tcg: Remove dh_alias indirection for dh_typecode
The dh_alias redirect is intended to handle TCG types as distinguished
from C types.  TCG does not distinguish signed int from unsigned int,
because they are the same size.  However, we need to retain this
distinction for dh_typecode, lest we fail to extend abi types properly
for the host call parameters.

This bug was detected when running the 'arm' emulator on an s390
system. The s390 uses TCG_TARGET_EXTEND_ARGS which triggers code
in tcg_gen_callN to extend 32 bit values to 64 bits; the incorrect
sign data in the typemask for each argument caused the values to be
extended as unsigned values.

This simple program exhibits the problem:

	static volatile int num = -9;
	static volatile int den = -5;
	int main(void)
	{
		int quo = num / den;
		printf("num %d den %d quo %d\n", num, den, quo);
		exit(0);
	}

When run on the broken qemu, this results in:

	num -9 den -5 quo 0

The correct result is:

	num -9 den -5 quo 1

Fixes: 7319d83a73 ("tcg: Combine dh_is_64bit and dh_is_signed to dh_typecode")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/876
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Tested-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-02-28 08:04:06 -10:00
..
hax
hvf
kvm KVM: x86: ignore interrupt_bitmap field of KVM_GET/SET_SREGS 2022-01-12 14:09:06 +01:00
nvmm nvmm: Fix support for stable version 2021-11-19 10:13:44 +01:00
tcg * Improve virtio-net failover test 2022-02-22 13:07:32 +00:00
whpx
arch_dump.c
arch_memory_mapping.c
cpu-dump.c
cpu-internal.h
cpu-param.h
cpu-qom.h
cpu-sysemu.c
cpu.c * More Meson conversions (0.59.x now required rather than suggested) 2022-02-21 17:24:05 +00:00
cpu.h target/i386: add TCG support for UMIP 2022-02-16 15:01:33 +01:00
gdbstub.c
helper.c * Improve virtio-net failover test 2022-02-22 13:07:32 +00:00
helper.h
host-cpu.c
host-cpu.h
Kconfig
machine.c KVM: use KVM_{GET|SET}_SREGS2 when supported. 2022-01-12 14:09:06 +01:00
meson.build
monitor.c
ops_sse_header.h tcg: Remove dh_alias indirection for dh_typecode 2022-02-28 08:04:06 -10:00
ops_sse.h
sev-sysemu-stub.c
sev.c
sev.h
shift_helper_template.h
svm.h
trace-events
trace.h
xsave_helper.c