spirious line removal

faccessat2 used by bash on arm64

if it works I have no objection)

if (error) to if (error != 0)

In D31259#704553, @trasz wrote:

On amd64 we have both 32-bit and 64-bit versions of linux_rt_sigsuspend(), though.

Linux futex documentation explicitly states that EINVAL is returned if
the futex is not 4-byte aligned. Check futex alignment as a Linux do
and return EINVAL.

In D31279#704398, @markj wrote:

In D31279#704382, @kib wrote:

In D31279#704379, @markj wrote:

In D31279#704348, @kib wrote:

But why is this check needed? We do not do similar checks in kern_umtx.c.

IMO MD casueword/fuword/suword interfaces must handle this case, e.g. returning EFAULT if unaligned userspace address is not acceptable (or silently do whatever is needed).

Hmm, for some reason I thought that umtx checks this. When are unaligned addresses ever acceptable? I don't see how e.g., fuword can silently handle unaligned addresses.

I am not sure what do you mean. If fuword causes unaligned exception on some architectures, then pcb_onfault handler can notice this and do whatever is needed to emulate the access.

Ok, I see. So according to your suggestion, amd64 fuword should fall back to a lock-prefixed instruction if it detects that the operand is unaligned.

I note though that the futex documentation explicitly states that EINVAL is returned if the object is not 4 byte-aligned, so I suspect that this change is still preferable for compatibility reasons.

Note that this still uses FreeBSD-style sigframe;
this will be addressed later.

In D31238#704112, @kib wrote:

In D31238#704101, @dchagin wrote:

UMTXQ_LOCKED_ASSERT?

Are you suggesting to call UMTXQ_ASSERT_LOCKED_BUSY() by UMTXQ_LOCKED_ASSERT() instead? The assert does both lock and busy checks, so IMO the longer name is more correct.

is rt_sigsuspend MD? seems that it can be moved to the MI code

style(9)

style(9)

done,
UMTXQ_LOCKED_ASSERT?

fixed, sorry(

s/u_int/uint32_t/

Follow the r349951 (30b3018d), add check to react to stops and requests
to terminate between retries.

done

futex_requeue should return (error)

the same problem as D31234

whoops, perhaps I fixed it

done

done,
sleep_pi may be should refactored to use this macros

yes, I think you are right, moreover, inline should be droped from function as
the compiler can ignore the inline qualifier and generate calls to the function if
the code is compiled without optimization for example

done, thanks!

Add umtx_ prefix to all abs_timeout facility, add declaration for it.
For consistency with others abs_timeout functions mark inline abs_timeout_init2.

blank line after { added in the umtx_key_match

done. thank you

style(9), comment about umtx_thread_exit,
fix error cleanup in case when futex succesfully acquired in lock_pi

In D31247#703645, @kib wrote:

Style requires a blank line before multi-line comment. Also it requires a blank line after end of the block described in the comment, in this case 422/423.