Le 29/01/2020 à 17:12, Laurent Vivier a écrit :
> Le 28/01/2020 à 10:26, Peter Maydell a écrit :
>> On Thu, 16 Jan 2020 at 11:58, Matus Kysel <mky...@tachyum.com> wrote:
>>>
>>> Used same style to handle another glibc reserved signal SIGSETXID (33),
>>> that is used by glibc NPTL setuid/setgid functions. This should fix problems
>>> with application using those functions and failing with error
>>> "qemu:handle_cpu_signal received signal outside vCPU context".
>>>
>>> Signed-off-by: Matus Kysel <mky...@tachyum.com>
>>> ---
>>> linux-user/signal.c | 13 +++++++++----
>>> 1 file changed, 9 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/linux-user/signal.c b/linux-user/signal.c
>>> index 0128bde4d2..c59221fd0a 100644
>>> --- a/linux-user/signal.c
>>> +++ b/linux-user/signal.c
>>> @@ -66,11 +66,16 @@ static uint8_t host_to_target_signal_table[_NSIG] = {
>>> [SIGPWR] = TARGET_SIGPWR,
>>> [SIGSYS] = TARGET_SIGSYS,
>>> /* next signals stay the same */
>>> - /* Nasty hack: Reverse SIGRTMIN and SIGRTMAX to avoid overlap with
>>> - host libpthread signals. This assumes no one actually uses
>>> SIGRTMAX :-/
>>> - To fix this properly we need to do manual signal delivery
>>> multiplexed
>>> - over a single host signal. */
>>> + /*
>>> + * Nasty hack: Swap SIGRTMIN and SIGRTMIN + 1 with SIGRTMAX and
>>> SIGRTMAX - 1
>>> + * to avoid overlap with host libpthread (NPTL glibc) signals.
>>> + * This assumes no one actually uses SIGRTMAX and SIGRTMAX - 1 :-/
>>> + * To fix this properly we need to do manual signal delivery
>>> multiplexed
>>> + * over a single host signal.
>>> + */
>>> [__SIGRTMIN] = __SIGRTMAX,
>>> + [__SIGRTMIN + 1] = __SIGRTMAX - 1,
>>> + [__SIGRTMAX - 1] = __SIGRTMIN + 1,
>>> [__SIGRTMAX] = __SIGRTMIN,
>>> };
>>> static uint8_t target_to_host_signal_table[_NSIG];
>>> --
>>> 2.17.1
>>
>> This is a long-standing known problem, but doing this is likely
>> to break currently-working guest binaries (notably things written
>> in Go). See for example the discussion on this thread:
>> https://lists.gnu.org/archive/html/qemu-devel/2019-08/msg03804.html
>
> Peter,
>
> I try to fix this problem and I'd like to find a reproducer for the Go
> problem.
>
> I tried to write an "hello world" program and run it in an arm64/bionic
> chroot but there is no problem (with and without this patch).
>
> Any hints?
Markus has sent me the information.
I'm able to reproduce the problem with an "Hello World" go program and
go 1.10 (basically ubuntu bionic/arm64).
Thanks,
Laurent
