kqueue.2: Editorial pass

[jhb]

Summary

• Use consistent language to describe user values unchanged by the kernel.

• Replace passive language with active in a few places.

• Add a history note for kqueuex().

• Various wording and markup tweaks.

[emaste]

OK, one little note.

lib/libsys/kqueue.2

115–116

The "also" here seems somewhat out of place to me for some reason but I'm not quite sure why. Maybe "Also, for compatibility with NetBSD the..." or "The kqueue1 function is also provided, for compatibility with NetBSD. It accepts..."

[jhb]

Tweak kqueue1 language

lib/libsys/Makefile.sys

init_proc0(vm_offset_t kstack)
         proc_linkup0(&proc0, &thread0);
         thread0.td_kstack = kstack;
         thread0.td_kstack_pages = kstack_pages;
 #if defined(PERTHREAD_SSP)
         thread0.td_md.md_canary = boot_canary;
 #endif
         thread0.td_pcb = (struct pcb *)(thread0.td_kstack +
             thread0.td_kstack_pages * PAGE_SIZE) - 1;
+        thread0.td_pcb->pcb_flags = 0;
         thread0.td_pcb->pcb_fpflags = 0;
         thread0.td_pcb->pcb_fpusaved = &thread0.td_pcb->pcb_fpustate;
         thread0.td_pcb->pcb_vfpcpu = UINT_MAX;
         thread0.td_frame = &proc0_tf;
         ptrauth_thread0(&thread0);
         pcpup->pc_curpcb = thread0.td_pcb;
 
         /*

lib/libsys/kqueue.2

init_proc0(vm_offset_t kstack)
         proc_linkup0(&proc0, &thread0);
         thread0.td_kstack = kstack;
         thread0.td_kstack_pages = kstack_pages;
 #if defined(PERTHREAD_SSP)
         thread0.td_md.md_canary = boot_canary;
 #endif
         thread0.td_pcb = (struct pcb *)(thread0.td_kstack +
             thread0.td_kstack_pages * PAGE_SIZE) - 1;
+        thread0.td_pcb->pcb_flags = 0;
         thread0.td_pcb->pcb_fpflags = 0;
         thread0.td_pcb->pcb_fpusaved = &thread0.td_pcb->pcb_fpustate;
         thread0.td_pcb->pcb_vfpcpu = UINT_MAX;
         thread0.td_frame = &proc0_tf;
         ptrauth_thread0(&thread0);
         pcpup->pc_curpcb = thread0.td_pcb;
 
         /*