linux(4): Fixup wait4 handling pid equal 0 case.

[dchagin]

Summary

Pid equal 0 meaning wait for any child process whose process group identificator
is equal to that of the calling process.

[emaste]

Special handling for -1 also needed

[emaste]

sys/compat/linux/linux_misc.c

1090

this should be pg_id no?

[dchagin]

In D31561#711580, @emaste wrote:

Special handling for -1 also needed

it handled by pid < 0, as pid == -1 before it

sys/compat/linux/linux_misc.c

1090

ah)) sure!

[emaste]

ah, #define WAIT_ANY (-1) /* any process */

[dchagin]

fixed

[dchagin]

abandon kern_getpgid

[emaste]

This is what I'd have expected and it LGTM, but I'd defer to @markj or @kib for confirmation

[kib]

In my copy of the FreeBSD source tree, linux_common_wait() has the following prototype

static int
linux_common_wait(struct thread *td, int pid, int *statusp,
    int options, struct __wrusage *wrup)

So I am not sure what is this about.

[dchagin]

In D31561#712206, @kib wrote:

In my copy of the FreeBSD source tree, linux_common_wait() has the following prototype

static int
linux_common_wait(struct thread *td, int pid, int *statusp,
    int options, struct __wrusage *wrup)

So I am not sure what is this about.

ah, it depends on D31552

[kib]

Do you mean that our native wait4(2) does not correctly handle pid == 0 case?

[dchagin]

In D31561#718208, @kib wrote:

Do you mean that our native wait4(2) does not correctly handle pid == 0 case?

hmm, no,
seems it's my fault in the https://reviews.freebsd.org/D31552, and should be fixed there