From: Benjamin Herrenschmidt <benh@kernel.crashing.org>

I added a full memory clobber on all asm accessors except the _raw
ones.

Signed-off-by: David S. Miller <davem@davemloft.net>

global_reg_snapshot shouldn't be visible in our userspace headers.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a cpu really is stuck in the kernel, it can be often
impossible to figure out which cpu is stuck where.  The
worst case is when the stuck cpu has interrupts disabled.

Therefore, implement a global cpu state capture that uses
SMP message interrupts which are not disabled by the
normal IRQ enable/disable APIs of the kernel.

As long as we can get a sysrq 'y' to the kernel, we can
get a dump.  Even if the console interrupt cpu is wedged,
we can trigger it from userspace using /proc/sysrq-trigger

The output is made compact so that this facility is more
useful on high cpu count systems, which is where this
facility will likely find itself the most useful :)

Signed-off-by: David S. Miller <davem@davemloft.net>

This patch removes the CVS keywords that weren't updated for a long time
from comments.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This mirrors x86 changeset 5a8da0ea82db6fa9737041381079fd16f25dcce2
("signals: x86 TS_RESTORE_SIGMASK") on sparc64.

Signed-off-by: David S. Miller <davem@davemloft.net>

Just like mmap, we need to validate address ranges regardless
of MAP_FIXED.

sparc{,64}_mmap_check()'s flag argument is unused, remove.

Based upon a report and preliminary patch by
Jan Lieskovsky <jlieskov@redhat.com>

Signed-off-by: David S. Miller <davem@davemloft.net>

So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal.  It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.

Problem is, this doesn't work.

The idea was that we should do the syscall restart business first, so
that the debugger captures that state.  Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.

The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.

In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb.  gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop().  The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal.  But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.

Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:

1) Report a "in syscall" software bit in regs->{tstate,psr}.
   It is set early on in trap entry to a system call and is fully
   visible to the debugger via ptrace() and regsets.

2) Test this bit right before doing a syscall restart.  We have
   to do a final recheck right after get_signal_to_deliver() in
   case the debugger cleared the bit during ptrace_stop().

3) Clear the bit in trap return so we don't accidently try to set
   that bit in the real register.

As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.

M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook.  It needs to be fixed in the same exact
way as sparc.

Signed-off-by: David S. Miller <davem@davemloft.net>

Forever we had a PTRACE_SUNOS_DETACH which was unconditionally
recognized, regardless of the personality of the process.

Unfortunately, this value is what ended up in the GLIBC sys/ptrace.h
header file on sparc as PTRACE_DETACH and PT_DETACH.

So continue to recognize this old value.  Luckily, it doesn't conflict
with anything we actually care about.

Signed-off-by: David S. Miller <davem@davemloft.net>

This modifies <asm-sparc64/types.h> to use the <asm-generic/int-*.h>
generic include files.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: David S. Miller <davem@davemloft.net>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc64: remove duplicated include
  sparc: Add kgdb support.
  kgdbts: Sparc needs sstep emulation.
  sparc32: Kill smp_message_pass() and related code.
  sparc64: Kill PIL_RESERVED, unused.
  sparc64: Split entry.S up into seperate files.