[PATCH v2 0/2] linux-user: fixes for sched_ syscalls

[Tonis Tiigi]

This patchset improves support for sched_* syscalls under user emulation. The 
first commit adds support for sched_g/setattr that was previously not 
implemented. There is no equivalent for these syscalls in libc, so I needed to 
redefine the struct from kernel. It can't be included directly because of 
conflict with libc sched headers.

The second commit fixes sched_g/setscheduler and sched_g/setparam, when QEMU is 
built with musl. Musl does not implement these due to conflict between what 
these functions should do in syscalls and libc 
https://git.musl-libc.org/cgit/musl/commit/?id=1e21e78bf7a5c24c217446d8760be7b7188711c2
 . I've changed it to call syscall directly what should always be the expected 
behavior for the user.

Via https://github.com/tonistiigi/binfmt/pull/70 with additional tests.

Changes v1->v2:
- Locking guest addresses for sched_attr is now based on size inputs, not local 
struct size. Also did the same for setter where I now read only the size field 
of the struct first.
- Use offsetof() when checking if optional fields are supported.
- `target_sched_attr` now uses aligned types as requested. I didn't quite 
understand why this is needed as I don't see same in kernel headers, but as 
this type uses only constant width fields and is already aligned by default it 
can't break anything.
- Fixed formatting.
- Defined own `target_sched_param` struct as requested.

Tonis Tiigi (2):
  linux-user: add sched_getattr support
  linux-user: call set/getscheduler set/getparam directly

 linux-user/syscall.c      | 112 +++++++++++++++++++++++++++++++++-----
 linux-user/syscall_defs.h |  18 ++++++
 2 files changed, 117 insertions(+), 13 deletions(-)

-- 
2.32.0 (Apple Git-132)