native version does non executable mappings on the stack. This is a
showstopper for Linux binaries.
To fix that we supply a copy f the native stack setup function for Linux
binaries, with the executable bit set.
otherwise, linux_syscall() returns garbage, at least on i386.
(it returns native_to_linux_errno[EPASSTHROUGH] where EPASSTHROUGH == -4.)
i choose EINVAL rather than ENOTTY, because linux's pipe returns it
and i think that it's a common case.
and tweak lkminit_*.c (where applicable) to call them, and to call
sysctl_teardown() when being unloaded.
This consists of (1) making setup functions not be static when being
compiled as lkms (change to sys/sysctl.h), (2) making prototypes
visible for the various setup functions in header files (changes to
various header files), and (3) making simple "load" and "unload"
functions in the actual lkminit stuff.
linux_sysctl.c also needs its root exposed (ie, made not static) for
this (when built as an lkm).
exec case, as the emulation already has the ability to intercept that
with the e_proc_exec hook. It is the responsability of the emulation to
take appropriaye action about lwp_emuldata in e_proc_exec.
Patch reviewed by Christos.
Gone are the old kern_sysctl(), cpu_sysctl(), hw_sysctl(),
vfs_sysctl(), etc, routines, along with sysctl_int() et al. Now all
nodes are registered with the tree, and nodes can be added (or
removed) easily, and I/O to and from the tree is handled generically.
Since the nodes are registered with the tree, the mapping from name to
number (and back again) can now be discovered, instead of having to be
hard coded. Adding new nodes to the tree is likewise much simpler --
the new infrastructure handles almost all the work for simple types,
and just about anything else can be done with a small helper function.
All existing nodes are where they were before (numerically speaking),
so all existing consumers of sysctl information should notice no
difference.
PS - I'm sorry, but there's a distinct lack of documentation at the
moment. I'm working on sysctl(3/8/9) right now, and I promise to
watch out for buses.
so that a specific emulation has the oportunity to filter out some signals.
if sigfilter returns 0, then no signal is sent by kpsignal2().
There is another place where signals can be generated: trapsignal. Since this
function is already an emulation hook, no call to the sigfilter hook was
introduced in trapsignal.
This is needed to emulate the softsignal feature in COMPAT_DARWIN (signals
sent as Mach exception messages)
and make the stack and heap non-executable by default. the changes
fall into two basic catagories:
- pmap and trap-handler changes. these are all MD:
= alpha: we already track per-page execute permission with the (software)
PG_EXEC bit, so just have the trap handler pay attention to it.
= i386: use a new GDT segment for %cs for processes that have no
executable mappings above a certain threshold (currently the
bottom of the stack). track per-page execute permission with
the last unused PTE bit.
= powerpc/ibm4xx: just use the hardware exec bit.
= powerpc/oea: we already track per-page exec bits, but the hardware only
implements non-exec mappings at the segment level. so track the
number of executable mappings in each segment and turn on the no-exec
segment bit iff the count is 0. adjust the trap handler to deal.
= sparc (sun4m): fix our use of the hardware protection bits.
fix the trap handler to recognize text faults.
= sparc64: split the existing unified TSB into data and instruction TSBs,
and only load TTEs into the appropriate TSB(s) for the permissions.
fix the trap handler to check for execute permission.
= not yet implemented: amd64, hppa, sh5
- changes in all the emulations that put a signal trampoline on the stack.
instead, we now put the trampoline into a uvm_aobj and map that into
the process separately.
originally from openbsd, adapted for netbsd by me.
truncate64() wrapper to translate args structure
NetBSD truncate() and ftrucate() have hidden 'pad' argument, so we have
to do the argument translation
Problem found and patch supplied in PR kern/22360 by Ales Krenek
This is the last of syscalls with hidden 'pad' arg we didn't have
wrapper for; all the others (lseek, mmap, pwrite, pread) already had
wrapper before.
manu