ABI and the direction flag, that is it now assumes that the direction
flag is cleared at the entry of a function and it doesn't clear once
more if needed. This new behaviour conforms to the i386/amd64 ABI.
Modify the signal handler frame setup code to clear the DF {e,r}flags
bit on the amd64/i386 for the signal handlers.
jhb@ noted that it might break old apps if they assumed DF == 1 would be
preserved in the signal handlers, but that such apps should be rare and
that older versions of gcc would not generate such apps.
Submitted by: Aurelien Jarno <aurelien aurel32 net>
PR: 121422
Reviewed by: jhb
MFC after: 2 weeks
Fix a debugging printf to printf after a variable is first assigned,
not before.
These are purely build fixes, and need inspection to make sure they
were what the original author of the previous changes intended.
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.
2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.
3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.
4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.
5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.
6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.
Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64
Make sigaltstack as per-threaded, because per-process sigaltstack state
is useless for threaded programs, multiple threads can not share same
stack.
The alternative signal stack is private for thread, no lock is needed,
the orignal P_ALTSTACK is now moved into td_pflags and renamed to
TDP_ALTSTACK.
For single thread or Linux clone() based threaded program, there is no
semantic changed, because those programs only have one kernel thread
in every process.
which left out SVR4 bits.
- Move struct sigacts out of the u-area and malloc() it using the
M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
and thread_stopped() are now MP safe.
Reviewed by: arch@
Approved by: re (rwatson)
a follow on commit to kern_sig.c
- signotify() now operates on a thread since unmasked pending signals are
stored in the thread.
- PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.
they aren't in the usual path of execution for syscalls and traps.
The main complication for this is that we have to set flags to control
ast() everywhere that changes the signal mask.
Avoid locking in userret() in most of the remaining cases.
Submitted by: luoqi (first part only, long ago, reorganized by me)
Reminded by: dillon
traps on the first instruction of signal handlers.
In trap.c:syscall(), fake a trace trap if the single-step flag was set
on entry to the kernel, not if it will be set on exit from the kernel.
This fixes bogus trace traps after the last instruction of signal handlers.
gdb-4.18 (the version in FreeBSD) still has problems with the program in
the PR. These seem to be due to bugs in gdb and not in FreeBSD, and are
fixed in gdb-5.1 (the distribution version).
PR: 33262
Tested by: k Macy <kip_macy@yahoo.com>
MFC after: 1 day
needlessly repeating the indirection in several places. Half of the places
used td->td_proc, and half used p. They are now consistent with each other
and all use p.
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
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)
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
depend on this. The linux ABI emulator tries to use it for some linux
binaries too. VM86 had a bigger cost than this and it was made default
a while ago.
Reviewed by: jhb, imp
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
eliminate warnings, etc.
Note that svr4_setcontext() and svr4_getcontext() currently don't work
correctly, which makes returning from signal handlers somewhat problematic
(for reference: the SysVR4 setcontext() and getcontext() syscalls behave
like a low-level version of setjmp() and longjmp(), in that they save and
restore process context. SysVR4 uses this to implement its signal handler
trampoline: The context which is saved before a signal handler is called
is restored by an implicit call to the setcontext() syscall when the signal
handler returns. That currently doesn't work right in this emulator,
although it used to).
I'm committing this anyway, with a caveat that it's buggy, so that I can
(a) note the bug for anyone who is wondering about it, and (b) get the
stuff I've done to improve (but not fix) the situation in the tree before
4.0 is released. If I have time to fix it totally RSN I'll talk to Jordan
to see if I can bend him into letting me commit a bugfix :-)
Note that the situation now is somewhat better than it was yesterday
anyway, because I've fixed the handling of svr4_sigsets which previously
was causing signal handlers to not get called at all. Stay tuned for
an upcoming commit to svr4_signal.c...
Include <sys/param.h> before <sys/assym.h> in case any of the magic
in the former is ever needed in the latter.
Removed an unused forward declaration and an unused include.
Merge the contents (less some trivial bordering the silly comments)
of <vm/vm_prot.h> and <vm/vm_inherit.h> into <vm/vm.h>. This puts
the #defines for the vm_inherit_t and vm_prot_t types next to their
typedefs.
This paves the road for the commit to follow shortly: change
useracc() to use VM_PROT_{READ|WRITE} rather than B_{READ|WRITE}
as argument.
can provide the correct context to each signal handler.
Fix broken sigsuspend(): don't use p_oldsigmask as a flag, use SAS_OLDMASK
as we did before the linuxthreads support merge (submitted by bde).
Move ps_sigstk from to p_sigacts to the main proc structure since signal
stack should not be shared among threads.
Move SAS_OLDMASK and SAS_ALTSTACK flags from sigacts::ps_flags to proc::p_flag.
Move PS_NOCLDSTOP and PS_NOCLDWAIT flags from proc::p_flag to procsig::ps_flag.
Reviewed by: marcel, jdp, bde
-----------------------------
The compatibility code and/or emulators have been updated:
iBCS2 now mostly uses the older syscalls. SVR4 now properly
handles all signals. This has been achieved by using the
new sigset_t throughout the emulator. The Linuxulator has
been severely updated. Internally the new Linux sigset_t is
made the default. These are then mapped to and from the
new FreeBSD sigset_t.
Also, rt_sigsuspend has been implemented in the Linuxulator.
Implementing this syscall basicly caused all this sigset_t
changing in the first place and the syscall has been used
throughout the change as a means for testing. It basicly is
too much work to undo the implementation so that it can
later be added again.
A special note on the use of sv_sigtbl and sv_sigsize in
struct sysentvec:
Every signal larger than sv_sigsize is not translated and is
passed on to the signal handler unmodified. Signals in the
range 1 upto and including sv_sigsize are translated.
The rationale is that only the system defined signals need to
be translated.
The emulators also have been updated so that the translation
tables are only indexed for valid (system defined) signals.
This change also fixes the translation bug already in the
SVR4 emulator.
- %fs register is added to trapframe and saved/restored upon kernel entry/exit.
- Per-cpu pages are no longer mapped at the same virtual address.
- Each cpu now has a separate gdt selector table. A new segment selector
is added to point to per-cpu pages, per-cpu global variables are now
accessed through this new selector (%fs). The selectors in gdt table are
rearranged for cache line optimization.
- fask_vfork is now on as default for both UP and SMP.
- Some aio code cleanup.
Reviewed by: Alan Cox <alc@cs.rice.edu>
John Dyson <dyson@iquest.net>
Julian Elischer <julian@whistel.com>
Bruce Evans <bde@zeta.org.au>
David Greenman <dg@root.com>
the address of the ps_strings structure to the process via %ebx.
For other kinds of binaries, %ebx is still zeroed as before.
Submitted by: Thomas Stephens <tas@stephens.org>
Reviewed by: jdp
