GCC-4.6 can find more unused code than previous versions could.

In the case of protected_restore_fp_context{,32}, the variable tmp is
really used.  Its use is tricky in that we really care about the side
effects of the __put_user() calls.  So we must mark tmp with
__maybe_unused to quiet the warning.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2035/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This is a follow on to the vdso patch.

Since all processes now have signal trampolines permanently mapped, we
can use those instead of putting the trampoline on the stack and
invalidating the corresponding icache across all CPUs.  We also get rid
of a bunch of ICACHE_REFILLS_WORKAROUND_WAR code.

[Ralf: GDB 7.1 which has the necessary modifications to allow backtracing
over signal frames will supposedly be released tomorrow.  The old signal
frame format obsoleted by this patch exists in two variations, for sane
processors and for those requiring ICACHE_REFILLS_WORKAROUND_WAR.  So
there was never a GDB which did support backtracing over signal frames
on all MIPS systems.  This convinved me this series should be applied and
pushed upstream as soon as possible.]
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/974/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/709/

Thanks to David Daney helping with debugging and testing.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>

This replaces mips's sys_ptrace32 with a compat_arch_ptrace and
enables the new generic definition of compat_sys_ptrace instead.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch removes some duplicate includes from arch/mips/
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NPavel Kiryukhin <vksavl@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

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>

The save_fp_context()/restore_fp_context() might sleep on accessing
user stack and therefore might lose FPU ownership in middle of them.

If these function failed due to "in_atomic" test in do_page_fault,
touch the sigcontext area in non-atomic context and retry these
save/restore operation.

This is a replacement of a (broken) fix which was titled "Allow CpU
exception in kernel partially".
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The commit 4d40bff7110e9e1a97ff8c01bdd6350e9867cc10 ("Allow CpU
exception in kernel partially") was broken.  The commit was to fix
theoretical problem but broke usual case.  Revert it for now.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit 6d667106 is incomplete and misses
non-r4k CPUs.  This patch reverts the commit and fixes in other way.

 o Do FCSR checking in caller of restore_fp_context.
 o Send SIGFPE if the signal handler set any FPU exception bits.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

native and compat do_signal and handle_signal are identical and can easily
be unified.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

access_ok in compat-signal.h is wrong (checking destination instead of
source) and redundant (already checked before calling this function).

Also sf_mask in struct sigframe32 should be compat_sigset_t type.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This macro was used to save static registers before calling
sys_sigsuspend() and sys_sigreturn().

For the sys_sigreturn() case, there's no point to save them
since they have been already saved by setup_sigcontext()
before calling the signal handler.

For the sys_sigsuspend() case, I don't see any reasons...
Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

All the information in the MIPS c0_status register is priviledged.
Nothing that would constitute part of the thread context.

The one flag one could possibly argument about might be c0_status.fr
but none of the ABIs or tools or application software can make use
of it.

So for consistency with restore_sigcontext32(), which does not
restore c0_status register, this patch remove the saving part.
Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This trivial changes should decrease a lot the size of these
2 functions.
Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

There's no point for signal32.c to redefine get_sigframe().
It should use the one define in signal.c instead.

The same stands for install_sigtramp().
Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch makes 'struct sigframe' declaration avalaible for all signals
code. It allows signal32 to not have its own declaration.

This patch also removes all ICACHE_REFILLS_WORKAROUND_WAR tests in
structure declaration and hopefully make them more readable.
Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

In entry.S resume_userspace ... jal do_notify_resume form a loop through
which the kernel will iterate as long as work is pending.  If we
iterate through this loop more than once with no signal pending for at
least one but the last iteration we will take do the syscall restarting
multiple times resulting in a syscall return prior to the the syscall
instruction in userspace.  This may happen when debugging a multithreaded
program.

Debugging and original fix by Maciej; extended to other ABIs by me.
Signed-off-by: NMaciej W. Rozycki <macro@mips.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

    
Move function prototypes to asm/signal.h to detect trivial errors and
add some __user tags to get rid of sparse warnings.  Generated code
should not be changed.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NMartin Michlmayr <tbm@cyrius.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

do_signal has been changed to return void since the "return value is
ignored everywhere".  Convert do_signal32 accordingly.
Signed-off-by: NMartin Michlmayr <tbm@cyrius.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

    
Following the recent implementation of TIF_RESTORE_SIGMASK in
arch/mips/kernel/signal.c, 64-bit kernels with 32-bit user-land
compatibility oops when starting init.  signal32.c needs to be
converted to use TIF_RESTORE_SIGMASK too.
Signed-off-by: NMartin Michlmayr <tbm@cyrius.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

---

Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>