On 6 September 2015 at 00:57, Timothy E Baldwin
<t.e.baldwi...@members.leeds.ac.uk> wrote:
> If there is a signal pending during fork() the signal handler will
> erroneously be called in both the parent and child, so handle any
> pending signals first.
>
> Signed-off-by: Timothy Edward Baldwin <t.e.baldwi...@members.leeds.ac.uk>
> ---
> linux-user/syscall.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 682090d..1ce381e 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -4731,6 +4731,11 @@ static int do_fork(CPUArchState *env, unsigned int
> flags, abi_ulong newsp,
> if ((flags & ~(CSIGNAL | CLONE_NPTL_FLAGS2)) != 0) {
> return -TARGET_EINVAL;
> }
> +
> + if (block_signals()) {
> + return -TARGET_ERESTARTSYS;
> + }
> +
> fork_start();
> ret = fork();
> if (ret == 0) {
This is in the fork part of do_fork(). In the clone part we
have some code which does "block all signals, then arrange to
restore them after the pthread_create in both threads". Can
we change that to work with the new block_signals approach?
(I have a feeling that in that case this call to block_signals
ends up being done earlier so it happens in both halves of
the function.)
If we block all signals here, what causes us to unblock them
again?
thanks
-- PMM
