Replace the a.out emulation of 'struct linker_set' with something
a little more flexible. <sys/linker_set.h> now provides macros for
accessing elements and completely hides the implementation.
The linker_set.h macros have been on the back burner in various
forms since 1998 and has ideas and code from Mike Smith (SET_FOREACH()),
John Polstra (ELF clue) and myself (cleaned up API and the conversion
of the rest of the kernel to use it).
The macros declare a strongly typed set. They return elements with the
type that you declare the set with, rather than a generic void *.
For ELF, we use the magic ld symbols (__start_<setname> and
__stop_<setname>). Thanks to Richard Henderson <rth@redhat.com> for the
trick about how to force ld to provide them for kld's.
For a.out, we use the old linker_set struct.
NOTE: the item lists are no longer null terminated. This is why
the code impact is high in certain areas.
The runtime linker has a new method to find the linker set
boundaries depending on which backend format is in use.
linker sets are still module/kld unfriendly and should never be used
for anything that may be modular one day.
Reviewed by: eivind
real uid, saved uid, real gid, and saved gid to ucred, as well as the
pcred->pc_uidinfo, which was associated with the real uid, only rename
it to cr_ruidinfo so as not to conflict with cr_uidinfo, which
corresponds to the effective uid.
o Remove p_cred from struct proc; add p_ucred to struct proc, replacing
original macro that pointed.
p->p_ucred to p->p_cred->pc_ucred.
o Universally update code so that it makes use of ucred instead of pcred,
p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo,
cr_{r,sv}{u,g}id instead of p_*, etc.
o Remove pcred0 and its initialization from init_main.c; initialize
cr_ruidinfo there.
o Restruction many credential modification chunks to always crdup while
we figure out locking and optimizations; generally speaking, this
means moving to a structure like this:
newcred = crdup(oldcred);
...
p->p_ucred = newcred;
crfree(oldcred);
It's not race-free, but better than nothing. There are also races
in sys_process.c, all inter-process authorization, fork, exec, and
exit.
o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid;
remove comments indicating that the old arrangement was a problem.
o Restructure exec1() a little to use newcred/oldcred arrangement, and
use improved uid management primitives.
o Clean up exit1() so as to do less work in credential cleanup due to
pcred removal.
o Clean up fork1() so as to do less work in credential cleanup and
allocation.
o Clean up ktrcanset() to take into account changes, and move to using
suser_xxx() instead of performing a direct uid==0 comparision.
o Improve commenting in various kern_prot.c credential modification
calls to better document current behavior. In a couple of places,
current behavior is a little questionable and we need to check
POSIX.1 to make sure it's "right". More commenting work still
remains to be done.
o Update credential management calls, such as crfree(), to take into
account new ruidinfo reference.
o Modify or add the following uid and gid helper routines:
change_euid()
change_egid()
change_ruid()
change_rgid()
change_svuid()
change_svgid()
In each case, the call now acts on a credential not a process, and as
such no longer requires more complicated process locking/etc. They
now assume the caller will do any necessary allocation of an
exclusive credential reference. Each is commented to document its
reference requirements.
o CANSIGIO() is simplified to require only credentials, not processes
and pcreds.
o Remove lots of (p_pcred==NULL) checks.
o Add an XXX to authorization code in nfs_lock.c, since it's
questionable, and needs to be considered carefully.
o Simplify posix4 authorization code to require only credentials, not
processes and pcreds. Note that this authorization, as well as
CANSIGIO(), needs to be updated to use the p_cansignal() and
p_cansched() centralized authorization routines, as they currently
do not take into account some desirable restrictions that are handled
by the centralized routines, as well as being inconsistent with other
similar authorization instances.
o Update libkvm to take these changes into account.
Obtained from: TrustedBSD Project
Reviewed by: green, bde, jhb, freebsd-arch, freebsd-audit
vm_mtx does not recurse and is required for most low level
vm operations.
faults can not be taken without holding Giant.
Memory subsystems can now call the base page allocators safely.
Almost all atomic ops were removed as they are covered under the
vm mutex.
Alpha and ia64 now need to catch up to i386's trap handlers.
FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).
Reviewed (partially) by: jake, jhb
handler in Linux emulation. According to bde, this is what Linux
does.
Recent versions of linuxthreads use %gs for thread-specific data,
while FreeBSD uses %fs (mostly because WINE uses %gs).
Tested by: drew
other "system" header files.
Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.
Sort sys/*.h includes where possible in affected files.
OK'ed by: bde (with reservations)
to call fork1() directly if we don't want out process queued right away.
This has the serendipitous side effect of saving us a call to pfind().
This makes threaded Linux apps (such as Opera) work again.
a regular basis. Adjust our linux emulation to conform. This will
cause more dirty pages to be left for the pagedaemon to deal with,
but our new low-memory handling code can deal with it. The linux
way appears to be a trend, and we may very well make MAP_NOSYNC the
default for FreeBSD as well (once we have reasonable sequential
write-behind heuristics for random faults).
(will be MFC'd prior to 4.3 freeze)
Suggested by: Andrew Gallatin
and used in C or vice versa. The elf compiler uses the same names
for both. Remove asnames.h with great prejudice; it has served its
purpose.
Note that this does not affect the ability to generate an aout kernel
due to gcc's -mno-underscores option.
moral support from: peter, jhb
waiting for procfs to get fixed:
- Use fill_eproc() to obtain correct VM stats. Attempt to compute VmLib.
- Fill some more fields in proc/<pid>/stat, and add four (unimplemented)
fields after studying a recent Linux kernel.
- Compute CPU frequency only once instead of twice.
- Fix some comments that were OBE.
- Fix indentation except where it makes the code less readable.
process is on the alternate stack or not. For compatibility
with sigstack(2) state is being updated if such is needed.
We now determine whether the process is on the alternate
stack by looking at its stack pointer. This allows a process
to siglongjmp from a signal handler on the alternate stack
to the place of the sigsetjmp on the normal stack. When
maintaining state, this would have invalidated the state
information and causing a subsequent signal to be delivered
on the normal stack instead of the alternate stack.
PR: 22286
struct sigframe. We need more than only the signal context.
o Properly convert the signal mask when setting up the signal
frame in linux_sendsig and properly convert it back in
linux_sigreturn.
Do some cleanups and improve style while here.
can unload. Doing so leaves the linuxulator in a crippled
state (no ioctl support) when Linux binaries are run at
unload time.
While here, consistently spell ELF in capitals and perform
some minor style improvements.
ELF spelling submitted by: asmodai
linux_rt_sendsig() and restore the same signal mask linux does
in rt_sigreturn(). This gets us saving/restoring all 64-bits of the
linux sigset_t in rt signals.
Reviewed by: marcel
linux_sigset_t by updating the linux_sigframe struct so as to include
linux's "extramask" field. This field contains the upper 32-bits of
the sigset. extramask sits behind a linux_fpstate struct, which I've
defined primarily for padding purposes.
While we're here, define LINUX_NSIG in terms of LINUX_NBPW (32) and
LINUX_NSIG_WORDS (2).
This fixes problems where threaded apps would accumulate a large
number of zombies. This was happening because the exit signal resides
in the upper 32-bits of the sigset and was never getting unmasked by
the manager thread after the first child exited.
PR: misc/18530 (may be related, originator not yet contacted)
Reviewed by: marcel
syscall compare against a variable sv_minsigstksz in struct
sysentvec as to properly take the size of the machine- and
ABI dependent struct sigframe into account.
The SVR4 and iBCS2 modules continue to have a minsigstksz of
8192 to preserve behavior. The real values (if different) are
not known at this time. Other ABI modules use the real
values.
The native MINSIGSTKSZ is now defined as follows:
Arch MINSIGSTKSZ
---- -----------
alpha 4096
i386 2048
ia64 12288
Reviewed by: mjacob
Suggested by: bde
stacks near the top of their address space. If their TOS is greater
than vm_maxsaddr, vm_map_growstack() will confuse the thread stack
with the process stack and deliver a SEGV if they attempt to grow the
thread stack past their current stacksize rlimit. To avoid this,
adjust vm_maxsaddr upwards to reflect the current stacksize rlimit
rather than the maximum possible stacksize. It would be better to
adjust the mmap'ed region, but some apps (again, IBM's JDK 1.3) do not
check mmap's return value..
This commit (in conjunction with setting MINSIGSTKSZ to 2048 &
rebuilding your kernel and modules) will get IBM's JDK 1.3 working
with FreeBSD at least well enough to run many of the example applets.
Reviewed by: marcel
Tested by: sto@stat.duke.edu, many others on freebsd-java@
and associated user-level signal trampoline glue.
Without this patch, an SA_SIGINFO style handler can be installed by a linux
app, but if the handler accesses its sip argument, it will get a garbage
pointer and likely segfault.
We currently supply a valid pointer, but its contents are mainly
garbage. Filling this in properly is future work.
This is the second of 3 commits that will get IBM's JDK 1.3 working with
FreeBSD ...
with FreeBSD (not including the MINSIGSTKSZ issue, which belongs to
Marcel). Due to time constraints, I'm going to space them out over a
few days.
This fixes two problems with linux_sigaltstack()
o ss == 0 is perfectly valid use, so do not fail in this case.
o Fix flag handling:
- Our SS_DISABLE is 4, linux's is 2, so we need conversion routines.
These conversion routines will be needed by linux_rt_sendsig()
and linux_rt_sigreturn (forthcoming), so they are not static.
- Linux's flag 0 historically meant SS_ONSTACK according to a comment
in their linux/kernel/signal.c file.
Among other things, this fixes a warning from Sun's JDK 1.3:
"Java HotSpot(TM) Client VM warning: cannot uninstall alt signal stack"
Reviewed by: marcel
Tested by: sto@stat.duke.edu, many others on freebsd-java@
