Re: [PATCH v3 1/2] linux-user/s390x: signal with SIGFPE on compare-and-trap

[Richard Henderson]

On 7/9/21 9:04 AM, Jonathan Albrecht wrote:
> Currently when a compare-and-trap instruction is executed, qemu will
> always raise a SIGILL signal. On real hardware, a SIGFPE is raised.
>
> Change the PGM_DATA case in cpu_loop to follow the behavior in
> linux kernel /arch/s390/kernel/traps.c.
>   * Only raise SIGILL if DXC == 0
>   * If DXC matches a non-simulated IEEE exception, raise SIGFPE with
>     correct si_code
>   * Raise SIGFPE with si_code == 0 for everything else
>
> When applied on20210705210434.45824-2-iii@linux.ibm.com, this fixes
> crashes in the java jdk such as the linked bug.
>
> Buglink:https://bugs.launchpad.net/qemu/+bug/1920913
> Resolves:https://gitlab.com/qemu-project/qemu/-/issues/319
> Signed-off-by: Jonathan Albrecht<jonathan.albrecht@linux.vnet.ibm.com>
> ---
>   linux-user/s390x/cpu_loop.c | 54 +++++++++++++++++++++++--------------
>   1 file changed, 34 insertions(+), 20 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~