introduce cpushutdown() function that does the common
operation of initiating shutdown, returning once all
cpu's got the message and are about to shutdown. this
avoids duplicated code which isnt really machine specific.
automatic reboot on panic only when *debug= is not set
and the machine is a cpu server or has no display,
otherwise just hang.
chacha20 comes in two variants: ietf rfc7539, using 96 bit iv and 32 bit counter
and draft-agl-tls-chacha20poly1305 using 64 bit iv and a 64 bit counter. so
setupChachastate() now takes a ivlen argument which sets the mode.
add ccpoly_encrypt()/ccpoly_decrypt() routines.
to implement timing safe ccpoly_decrypt(), a constant time memcmp was needed, so
adding tsmemcmp() to libsec.
when the "resize" wctl was used on a hidden window, the window
was put back on the screen, however, it was not removed from
the hidden[] array so trying to hide the window again failed
because whide() assumed it was already hidden.
the fix is to not unhide the window, but preserve the hidden
state, so windows can programmatically be reshaped and moved,
but will remain hidden unless explicitely unhidden.
to solve the usb device enumeration race on boot, usbd creates /env/usbbusy
on startup and once all devices have been enumerated and readers have consumed
all the events, we remove the file so nusbrc/bootrc can continue. this makes
sure all the usb devices that where plugged in on boot are made available.
when opening a /env file ORCLOSE, and the process exits, envgrp() would
return nil can crash in envremove() because procexit will have set up->egrp
to nil before calling closefgrp().
the solution is to capture the environment on open, keeping a reference in
Chan.aux, so it doesnt matter on what process the close happens and a
env chan will always refer to its original environment group.
instead of checking addr+len >= addr, check len >= -addr so
that addr == 0 is never valid for len > 0 even if we decide
to have memory at the zero page so theres never any chance
user can pass in "nil" pointers.
put up some signs where we fall thru the switch cases in
fixfault()
sha256 is only defined for TLS1.2, however, technically, theres
no reason not to use it in TLS1.0/TLS1.1. the choice is up to
tlshand and pushtls, not the kernel.
