This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
vm_offset_t is currently unsigned long but should probably be plain
unsigned for i386's to match the choice of minimal types to represent
for fixed-width types in Lite2. Anyway, it shouldn't be assumed
to be unsigned long.
I only fixed the type mismatches that were detected when I changed
vm_offset_t to unsigned. Only pointer type mismatches were detected.
netscape-2.0 for Linux running all the Java stuff. The scrollbars are now
working, at least on my machine. (whew! :-)
I'm uncomfortable with the size of this commit, but it's too
inter-dependant to easily seperate out.
The main changes:
COMPAT_LINUX is *GONE*. Most of the code has been moved out of the i386
machine dependent section into the linux emulator itself. The int 0x80
syscall code was almost identical to the lcall 7,0 code and a minor tweak
allows them to both be used with the same C code. All kernels can now
just modload the lkm and it'll DTRT without having to rebuild the kernel
first. Like IBCS2, you can statically compile it in with "options LINUX".
A pile of new syscalls implemented, including getdents(), llseek(),
readv(), writev(), msync(), personality(). The Linux-ELF libraries want
to use some of these.
linux_select() now obeys Linux semantics, ie: returns the time remaining
of the timeout value rather than leaving it the original value.
Quite a few bugs removed, including incorrect arguments being used in
syscalls.. eg: mixups between passing the sigset as an int, vs passing
it as a pointer and doing a copyin(), missing return values, unhandled
cases, SIOC* ioctls, etc.
The build for the code has changed. i386/conf/files now knows how
to build linux_genassym and generate linux_assym.h on the fly.
Supporting changes elsewhere in the kernel:
The user-mode signal trampoline has moved from the U area to immediately
below the top of the stack (below PS_STRINGS). This allows the different
binary emulations to have their own signal trampoline code (which gets rid
of the hardwired syscall 103 (sigreturn on BSD, syslog on Linux)) and so
that the emulator can provide the exact "struct sigcontext *" argument to
the program's signal handlers.
The sigstack's "ss_flags" now uses SS_DISABLE and SS_ONSTACK flags, which
have the same values as the re-used SA_DISABLE and SA_ONSTACK which are
intended for sigaction only. This enables the support of a SA_RESETHAND
flag to sigaction to implement the gross SYSV and Linux SA_ONESHOT signal
semantics where the signal handler is reset when it's triggered.
makesyscalls.sh no longer appends the struct sysentvec on the end of the
generated init_sysent.c code. It's a lot saner to have it in a seperate
file rather than trying to update the structure inside the awk script. :-)
At exec time, the dozen bytes or so of signal trampoline code are copied
to the top of the user's stack, rather than obtaining the trampoline code
the old way by getting a clone of the parent's user area. This allows
Linux and native binaries to freely exec each other without getting
trampolines mixed up.
- Optimise the linux a.out loading and uselib system calls so they
take advantage of some of John's recent interface improvements.
Basically, this means they make far less map changes than before.
- Attempt to plug some potentially nasty kernel_map memory leaks..
- Improve support for QMAGIC libs (I only use QMAGIC (ie: a.out libraries from
the slackware 3.0 dist) but this depends on other changes to enhance
the /compat/linux support)
- uselib goes out through a single exit as part of the resource tracking
that I did when closing the resource leaks on errors. This could be
cleaner than what I did, but making a 30-deep nested if/else was not my
idea of fun, neither did I want to repeat the same code 30 times over for
each failure possibility. I guess this function needs to be split into
smaller functions to solve this.
I've been running the Linux Netscape-2.0 (with Java) to test this, and apart
from the long-standing problem with the missing scrollbars, it appears to
still work as before with ZMAGIC libs (and the leaks).. However, I've
been using it with mods for the signal trampoline code for native linux stack
frames on signals and exterminated the blasted sigreturn printf() problem,
so I can't be certain that there is not a dependency on something else.
successfully run linux netscape 2.0b3 with a QMAGIC ld.so and libc/libm
that I found on some linux machine that I _think_ is running slackware 3.0.
There are still problems.. ld.so claims the libraries are the wrong
format, but it still runs anyway.. :-/ The QMAGIC ld.so also screams
about needing ld.so.cache, and running a linux ldconfig is quite
educational. You soon learn to run "chroot /compat/linux /bin/ldconfig"
where ldconfig is living in /compat/linux/bin. :-]
(Lets just say that it puts loads of symlinks in /usr/lib otherwise :-)
Changed vnodep -> vp for consistency with the rest of the kernel, and
changed iparams -> imgp for brevity.
kern_exec.c:
Explicitly initialized some additional parts of the image_params struct
to avoid bzeroing it. Rewrote the set-id code to reduce the number of
logical tests. The rewrite exposed a mostly benign bug in the algorithm:
traced set-id images would get ktracing disabled even if the set-id didn't
happen for other reasons.
Obtained from: other people on the net ?
1. stepping over syscalls (gdb ni) sends you to DDB, and returned
to the wrong address afterwards, with or without DDB. patch in
i386/i386/trap.c below.
2. the linux emulator (modload'ed) still causes panics with DIAGNOSTIC,
re-applied a patch posted to one of the lists...
This first shot only incorporaties so much functionality that DOOM
can run (the X version), signal handling is VERY weak, so is many
other things. But it meets my milestone number one (you guessed it
- running DOOM).
Uses /compat/linux as prefix for loading shared libs, so it won't
conflict with our own libs.
Kernel must be compiled with "options COMPAT_LINUX" for this to work.
