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.
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.
memory fault handler. IRIX uses irix_vm_fault, and all other emulation
use NULL, which means to use uvm_fault.
- While we are there, explicitely set to NULL the uninitialized fields in
struct emul: e_fault and e_sysctl on most ports
- e_fault is used by the trap handler, for now only on mips. In order to avoid
intrusive modifications in UVM, the function pointed by e_fault does not
has exactly the same protoype as uvm_fault:
int uvm_fault __P((struct vm_map *, vaddr_t, vm_fault_t, vm_prot_t));
int e_fault __P((struct proc *, vaddr_t, vm_fault_t, vm_prot_t));
- In IRIX share groups, all the VM space is shared, except one page.
This bounds us to have different VM spaces and synchronize modifications
to the VM space accross share group members. We need an IRIX specific hook
to the page fault handler in order to propagate VM space modifications
caused by page faults.
format specific.
Struct emul has a e_setregs hook back, which points to emulation-specific
setregs function. es_setregs of struct execsw now only points to
optional executable-specific setup function (this is only used for
ECOFF).
Async I/O OS specifities should now handled in OS specific code. Linux
has been done, but other emulation should be handled. See case LINUX_F_SETFL
in sys/compat/linux/common/linux_file.c:linux_sys_fcntl() for more details.
The data that has been collected yet:
Net Free Open Linux SunOS AIX OSF1 Darwin
send SIGIO to write end of pipe Y N N N N N Y Y
send SIGIO to read end of pipe Y Y N N N ? Y ?
send SIGIO to write end of socket Y Y Y N N Y Y Y
send SIGIO to read end of socket Y Y Y Y Y ? Y ?
* __HAVE_SYSCALL_INTERN. If this is defined, e_syscall is replaced by
e_syscall_intern, which is called at key places in the kernel. This can be
used to set a MD syscall handler pointer. This obsoletes and replaces the
*_HAS_SEPARATED_SYSCALL flags.
* __HAVE_MINIMAL_EMUL. If this is defined, certain (deprecated) elements in
struct emul are omitted.
*_emul_path variables
change macros CHECK_ALT_{CREAT|EXIST} to use that, 'root' doesn't need
to be passed explicitly any more and *_CHECK_ALT_{CREAT|EXIST} are removed
change explicit emul_find() calls in probe functions to get the emulation
path from the checked exec switch entry's emulation
remove no longer needed header files
add e_flags and e_syscall to struct emul; these are unsed and empty for now
* move all exec-type specific information from struct emul to execsw[] and
provide single struct emul per emulation
* elf:
- kern/exec_elf32.c:probe_funcs[] is gone, execsw[] how has one entry
per emulation and contains pointer to respective probe function
- interp is allocated via MALLOC() rather than on stack
- elf_args structure is allocated via MALLOC() rather than malloc()
* ecoff: the per-emulation hooks moved from alpha and mips specific code
to OSF1 and Ultrix compat code as appropriate, execsw[] has one entry per
emulation supporting ecoff with appropriate probe function
* the makecmds/probe functions don't set emulation, pointer to emulation is
part of appropriate execsw[] entry
* constify couple of structures
* Don't try to use auxiliary arguments with statically linked executables.
* Remove 'cannot find interpreter' uprintf, as other exec modules may
succeed in running the binary after all, and then we don't want this message.
* Some linkers produce rw- for the data segment, not rwx.
* Remove a few debugging printfs
2. many termio, ioctl, sigaction fixes
3. better socket type emulation; still ticotsord [the loopback interface I
guess] does not work properly on svr4 4.1.
4. new gettimeofday, fixed utssys..
5. rmdir and mkdir were swapped in syscalls.master
fvdl