blocked in the kernel. The task that catched the exception may unblock
it by sending a reply to the exception message (Of course it will have
to change something so that the exception is not immediatly raised again).
Handling of this reply is a bit complicated, as the kernel acts as the
client instead of the server. In this situation, we receive a message
but we will not send any reply (the message we receive is already a reply).
I have not found anything better than a special case in
mach_msg_overwrite_trap() to handle this.
A surprise: exceptions ports are preserved accross forks.
While we are there, use appropriate 64 bit types for make_memory_entry_64.
may turn into exceptions on Mach: a small message sent by the kernel to
the task that requested the exception.
On Darwin, when an exception is sent, no signal can be delivered.
TODO: more exceptions: arithmetic, bad instructions, emulation, s
software, and syscalls (plain and Mach). There is also RPC alert, but
I have no idea about what it is.
While we are there, remove some user ktrace in notification code, and add
a NODEF qualifier in mach_services.master: it will be used for notifications
and exceptions, where the kernel is always client and never server: we
don't want the message to be displayed as "unimplemented xxx" in kdump (thus
UNIMPL is not good), but we don't want to generate the server prototype
(therefore, STD is not good either). NODEF will declare it normally in the
name tables without creating the prototype.
will have unimplemented services showing their names in ktrace
Add a new generated file with only service id and name, which will
be included by kdump to display services names.
This removes the need for using the user ktrace facility for services names.
1) make sure Mach servers will not work on data beyond the end of the
request message buffer.
2) make sure that on copying out the reply message buffer, we will not
leak kernel data located after the buffer.
3) make sure that the server will not overwrite memory beyond the end
of the reply message buffer. That check is the responsability of the
server, there is just a DIAGNOSTIC test to check everything is in
good shape. All currently implemented servers in NetBSD have been
modified to check for this condition
While we are here, build the mach services table (formerly in mach_namemap.c)
and the services prototypes automatically from mach_services.master, just
as this is done for system calls.
The next step would be to fold the message formats in the mach_services.master
file, but this tends to be difficult, as some messages are quite long and
complex.
manu