We need to be more liberal about the alignment of the buffer given to
us by sigaltstack().  The user should not need to be mindful of all of
the alignment constraints we have for the stack frame.

This mirrors how we handle this situation in clone() as well.

Also, we align the stack even in non-SA_ONSTACK cases so that signals
due to bad stack alignment can be delivered properly.  This makes such
errors easier to debug and recover from.

Finally, add the sanity check x86 has to make sure we won't overflow
the signal stack.

This fixes glibc testcases nptl/tst-cancel20.c and
nptl/tst-cancelx20.c
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The change I put into copy_thread() just papered over the real
problem.

When we are looking to see if we should do a syscall restart, when
deliverying a signal, we should only interpret the syscall return
value as an error if the carry condition code(s) are set.

Otherwise it's a success return.

Also, sigreturn paths should do a pt_regs_clear_trap_type().

It turns out that doing a syscall restart when returning from a fork()
does and should happen, from time to time.  Even if copy_thread()
returns success, copy_process() can still unwind and signal
-ERESTARTNOINTR in the parent.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Back around the same time we were bootstrapping the first 32-bit sparc
Linux kernel with a SunOS userland, we made the signal frame match
that of SunOS.

By the time we even started putting together a native Linux userland
for 32-bit Sparc we realized this layout wasn't sufficient for Linux's
needs.

Therefore we changed the layout, yet kept support for the old style
signal frame layout in there.  The detection mechanism is that we had
sys_sigaction() start passing in a negative signal number to indicate
"new style signal frames please".

Anyways, no binaries exist in the world that use the old stuff.  In
fact, I bet Jakub Jelinek and myself are the only two people who ever
had such binaries to be honest.

So let's get rid of this stuff.

I added an assertion using WARN_ON_ONCE() that makes sure 32-bit
applications are passing in that negative signal number still.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that we can check the trap type directly, we don't need the
funny restart_syscall indication from the trap return paths.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As per Documentation/feature-removal-schedule.txt
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Create asm-sparc64/compat_signal.h and stuff things there.

This avoids the "linux/compat.h includes asm/signal.h but
asm/signal.h needs compat_sigset_t which isn't defined yet"
problems introduced recently.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This also includes by necessity _TIF_RESTORE_SIGMASK support,
which actually resulted in a lot of cleanups.

The sparc signal handling code is quite a mess and I should
clean it up some day.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sparc64 prom_callback and new_setup_frame32 each operates on a user page
table without holding lock, and no doubt they've good reason.  But I'd
feel more confident if they were to do a "pte = *ptep" and then operate
on pte, rather than re-evaluating *ptep.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It appears that a memory barrier soon after a mispredicted
branch, not just in the delay slot, can cause the hang
condition of this cpu errata.

So move them out-of-line, and explicitly put them into
a "branch always, predict taken" delay slot which should
fully kill this problem.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It has been reported that the way Linux handles NODEFER for signals is
not consistent with the way other Unix boxes handle it.  I've written a
program to test the behavior of how this flag affects signals and had
several reports from people who ran this on various Unix boxes,
confirming that Linux seems to be unique on the way this is handled.

The way NODEFER affects signals on other Unix boxes is as follows:

1) If NODEFER is set, other signals in sa_mask are still blocked.

2) If NODEFER is set and the signal is in sa_mask, then the signal is
still blocked. (Note: this is the behavior of all tested but Linux _and_
NetBSD 2.0 *).

The way NODEFER affects signals on Linux:

1) If NODEFER is set, other signals are _not_ blocked regardless of
sa_mask (Even NetBSD doesn't do this).

2) If NODEFER is set and the signal is in sa_mask, then the signal being
handled is not blocked.

The patch converts signal handling in all current Linux architectures to
the way most Unix boxes work.

Unix boxes that were tested:  DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.

* NetBSD was the only other Unix to behave like Linux on point #2. The
main concern was brought up by point #1 which even NetBSD isn't like
Linux.  So with this patch, we leave NetBSD as the lonely one that
behaves differently here with #2.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch is based on work by Carlos O'Donell and Matthew Wilcox.  It
introduces/updates the compat_time_t type and uses it for compat siginfo
structures.  I have built this on ppc64 and x86_64.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The compat routine to copy over this data structure was not
handling SI_POLL correctly, breaking various fcntl() variants
in compat tasks.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!