This way we can use same data type struct with KVM and
also help in using other debug related function.
Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
Acked-by: NMichael Neuling <mikey@neuling.org>
[scottwood@freescale.com: removed obvious debug_reg comment]
Signed-off-by: NScott Wood <scottwood@freescale.com>

This creates new 'thread_fp_state' and 'thread_vr_state' structures
to store FP/VSX state (including FPSCR) and Altivec/VSX state
(including VSCR), and uses them in the thread_struct.  In the
thread_fp_state, the FPRs and VSRs are represented as u64 rather
than double, since we rarely perform floating-point computations
on the values, and this will enable the structures to be used
in KVM code as well.  Similarly FPSCR is now a u64 rather than
a structure of two 32-bit values.

This takes the offsets out of the macros such as SAVE_32FPRS,
REST_32FPRS, etc.  This enables the same macros to be used for normal
and transactional state, enabling us to delete the transactional
versions of the macros.   This also removes the unused do_load_up_fpu
and do_load_up_altivec, which were in fact buggy since they didn't
create large enough stack frames to account for the fact that
load_up_fpu and load_up_altivec are not designed to be called from C
and assume that their caller's stack frame is an interrupt frame.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We always take signals in big endian which is wrong. Signals
should be taken in native endian.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Since 2002, the kernel has not saved VRSAVE on exception entry and
restored it on exit; rather, VRSAVE gets context-switched in _switch.
This means that when executing in process context in the kernel, the
userspace VRSAVE value is live in the VRSAVE register.

However, the signal code assumes that current->thread.vrsave holds
the current VRSAVE value, which is incorrect.  Therefore, this
commit changes it to use the actual VRSAVE register instead.  (It
still uses current->thread.vrsave as a temporary location to store
it in, as __get_user and __put_user can only transfer to/from a
variable, not an SPR.)

This also modifies the transactional memory code to save and restore
VRSAVE regardless of whether VMX is enabled in the MSR.  This is
because accesses to VRSAVE are not controlled by the MSR.VEC bit,
but can happen at any time.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we only restore signals which are transactionally suspended but it's
possible that the transaction can be restored even when it's active.  Most
likely this will result in a transactional rollback by the hardware as the
transaction will have been doomed by an earlier treclaim.

The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel.  That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
assumptions based on having software rollback.

This changes the signal return code to always restore both contexts on 32 bit
rt signal return.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we clear out the MSR TM bits on signal return assuming that the
signal should never return to an active transaction.

This is bogus as the user may do this.  It's most likely the transaction will
be doomed due to a treclaim but that's a problem for the HW not the kernel.

The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel.  That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
the assumption that it must be returning to a suspended transaction.

This pulls out both MSR TM bits from the user supplied context rather than just
setting TM suspend.  We pull out only the bits needed to ensure the user can't
do anything dangerous to the MSR.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently sys_sigreturn() is TM unaware.  Therefore, if we take a 32 bit signal
without SIGINFO (non RT) inside a transaction, on signal return we don't
restore the signal frame correctly.

This checks if the signal frame being restoring is an active transaction, and
if so, it copies the additional state to ptregs so it can be restored.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The MSR TM controls are in the top 32 bits of the MSR hence on 32 bit signals,
we stick the top half of the MSR in the checkpointed signal context so that the
user can access it.

Unfortunately, we don't currently write anything to the checkpointed signal
context when coming in a from a non transactional process and hence the top MSR
bits can contain junk.

This updates the 32 bit signal handling code to always write something to the
top MSR bits so that users know if the process is transactional or not and the
kernel can use it on signal return.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When in an active transaction that takes a signal, we need to be careful with
the stack.  It's possible that the stack has moved back up after the tbegin.
The obvious case here is when the tbegin is called inside a function that
returns before a tend.  In this case, the stack is part of the checkpointed
transactional memory state.  If we write over this non transactionally or in
suspend, we are in trouble because if we get a tm abort, the program counter
and stack pointer will be back at the tbegin but our in memory stack won't be
valid anymore.

To avoid this, when taking a signal in an active transaction, we need to use
the stack pointer from the checkpointed state, rather than the speculated
state.  This ensures that the signal context (written tm suspended) will be
written below the stack required for the rollback.  The transaction is aborted
becuase of the treclaim, so any memory written between the tbegin and the
signal will be rolled back anyway.

For signals taken in non-TM or suspended mode, we use the
normal/non-checkpointed stack pointer.

Tested with 64 and 32 bit signals
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We can't compile a kernel with CONFIG_ALTIVEC=n when
CONFIG_PPC_TRANSACTIONAL_MEM=y.  We currently get:

arch/powerpc/kernel/tm.S:320: Error: unsupported relocation against THREAD_VSCR
arch/powerpc/kernel/tm.S:323: Error: unsupported relocation against THREAD_VR0
arch/powerpc/kernel/tm.S:323: Error: unsupported relocation against THREAD_VR0
etc.

The below fixes this with a sprinkling of #ifdefs.

This was found by mpe with kisskb:
  http://kisskb.ellerman.id.au/kisskb/buildresult/8539442/Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>

This adds the new transactional memory archtected state to the signal context
in both 32 and 64 bit.
Signed-off-by: NMatt Evans <matt@ozlabs.org>
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This include is no longer needed.
(seems to be a leftover from try_to_freeze())
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... it's just a call of set_current_blocked() now
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

guts of saved_sigmask-based sigsuspend/rt_sigsuspend.  Takes
kernel sigset_t *.

Open-coded instances replaced with calling it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Disintegrate asm/system.h for PowerPC.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
cc: linuxppc-dev@lists.ozlabs.org

As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block
is pending in the shared queue.

Also, use the new helper function introduced in commit 5e6292c0
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate
code across architectures. In the past some architectures got this
code wrong, so using this helper function should stop that from
happening again.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On PPC64, put_sigset_t converts a sigset_t to a compat_sigset_t
before copying it to userspace. There is a typo in the case that
we have 4 words to copy, meaning that we corrupt the compat_sigset_t.

It appears that _NSIG_WORDS can't be greater than 2 at the moment
so this code is probably always optimised away anyway.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Since printk_ratelimit() shouldn't be used anymore (see comment in
include/linux/printk.h), replace it with printk_ratelimited.
Signed-off-by: NChristian Dietrich <christian.dietrich@informatik.uni-erlangen.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Make sigreturn zero regs->trap, make do_signal() do the same on all
paths.  As it is, signal interrupting e.g. read() from fd 512 (==
ERESTARTSYS) with another signal getting unblocked when the first
handler finishes will lead to restart one insn earlier than it ought
to.  Same for multiple signals with in-kernel handlers interrupting
that sucker at the same time.  Same for multiple signals of any kind
interrupting that sucker on 64bit...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

powerpc/booke: Add support for advanced debug registers

From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>

Based on patches originally written by Torez Smith.

This patch defines context switch and trap related functionality
for BookE specific Debug Registers. It adds support to ptrace()
for setting and getting BookE related Debug Registers
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Torez Smith  <lnxtorez@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <dwg@au1.ibm.com>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Sergio Durigan Junior <sergiodj@br.ibm.com>
Cc: Thiago Jung Bauermann <bauerman@br.ibm.com>
Cc: linuxppc-dev list <Linuxppc-dev@ozlabs.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/booke: Introduce new CONFIG options for advanced debug registers

From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>

Introduce new config options to simplify the ifdefs pertaining to the
advanced debug registers for booke and 40x processors:

CONFIG_PPC_ADV_DEBUG_REGS - boolean: true for dac-based processors
CONFIG_PPC_ADV_DEBUG_IACS - number of IAC registers
CONFIG_PPC_ADV_DEBUG_DACS - number of DAC registers
CONFIG_PPC_ADV_DEBUG_DVCS - number of DVC registers
CONFIG_PPC_ADV_DEBUG_DAC_RANGE - DAC ranges supported

Beginning conservatively, since I only have the facilities to test 440
hardware.  I believe all 40x and booke platforms support at least 2 IAC
and 2 DAC registers.  For 440, 4 IAC and 2 DVC registers are enabled, as
well as the DAC ranges.
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Acked-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On powerpc64 machines running 32-bit userspace, we can get garbage bits in the
stack pointer passed into the kernel.  Most places handle this correctly, but
the signal handling code uses the passed value directly for allocating signal
stack frames.

This fixes the issue by introducing a get_clean_sp function that returns a
sanitized stack pointer.  For 32-bit tasks on a 64-bit kernel, the stack
pointer is masked correctly.  In all other cases, the stack pointer is simply
returned.

Additionally, we pass an 'is_32' parameter to get_sigframe now in order to
get the properly sanitized stack.  The callers are know to be 32 or 64-bit
statically.
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The new context may not be 16-byte aligned, so the real address of the
mcontext structure should be read from the uc_regs pointer instead of
directly using the (unaligned) uc_mcontext field.
Signed-off-by: NAndreas Schwab <schwab@suse.de>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Since VSX support was added, we now have two sizes of ucontext_t;
the older, smaller size without the extra VSX state, and the new
larger size with the extra VSX state.  A program using the
sys_swapcontext system call and supplying smaller ucontext_t
structures will currently get an EINVAL error if the task has
used VSX (e.g. because of calling library code that uses VSX) and
the old_ctx argument is non-NULL (i.e. the program is asking for
its current context to be saved).  Thus the program will start
getting EINVAL errors on calls that previously worked.

This commit changes this behaviour so that we don't send an EINVAL in
this case.  It will now return the smaller context but the VSX MSR bit
will always be cleared to indicate that the ucontext_t doesn't include
the extra VSX state, even if the task has executed VSX instructions.

Both 32 and 64 bit cases are updated.

[paulus@samba.org - also fix some access_ok() and get_user() calls]

Thanks to Ben Herrenschmidt for noticing this problem.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

giveup_vsx didn't save the FPU and VMX regsiters.  Change it to be
like giveup_fpr/altivec which save these registers.

Also update call sites where FPU and VMX are already saved to use the
original giveup_vsx (renamed to __giveup_vsx).
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When the ucontext changed to add the VSX context, this broke backwards
compatibly on swapcontext.  swapcontext only compares the ucontext size
passed in from the user to the new kernel ucontext size.

This adds a check against the old ucontext size (with VMX but without
VSX).  It also adds some sanity check for ucontexts without VSX, but
where VSX is used according the MSR.  Fixes for both 32 and 64bit
processes on 64bit kernels

Kudos to Paulus for noticing.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This merges and cleans up some of the ugly copy/to from user code
which is required for the new fpr and vsx layout in the thread_struct.

Also fixes some hard coded buffer sizes and removes a redundant
fpr_flush_to_thread.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This patch extends the floating point save and restore code to use the
VSX load/stores when VSX is available.  This will make FP context
save/restore marginally slower on FP only code, when VSX is available,
as it has to load/store 128bits rather than just 64bits.

Mixing FP, VMX and VSX code will get constant architected state.

The signals interface is extended to enable access to VSR 0-31
doubleword 1 after discussions with tool chain maintainers.  Backward
compatibility is maintained.

The ptrace interface is also extended to allow access to VSR 0-31 full
registers.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The layout of the new VSR registers and how they overlap on top of the
legacy FPR and VR registers is:

                   VSR doubleword 0               VSR doubleword 1
          ----------------------------------------------------------------
  VSR[0]  |             FPR[0]            |                              |
          ----------------------------------------------------------------
  VSR[1]  |             FPR[1]            |                              |
          ----------------------------------------------------------------
          |              ...              |                              |
          |              ...              |                              |
          ----------------------------------------------------------------
  VSR[30] |             FPR[30]           |                              |
          ----------------------------------------------------------------
  VSR[31] |             FPR[31]           |                              |
          ----------------------------------------------------------------
  VSR[32] |                             VR[0]                            |
          ----------------------------------------------------------------
  VSR[33] |                             VR[1]                            |
          ----------------------------------------------------------------
          |                              ...                             |
          |                              ...                             |
          ----------------------------------------------------------------
  VSR[62] |                             VR[30]                           |
          ----------------------------------------------------------------
  VSR[63] |                             VR[31]                           |
          ----------------------------------------------------------------

VSX has 64 128bit registers.  The first 32 regs overlap with the FP
registers and hence extend them with and additional 64 bits.  The
second 32 regs overlap with the VMX registers.

This commit introduces the thread_struct changes required to reflect
this register layout.  Ptrace and signals code is updated so that the
floating point registers are correctly accessed from the thread_struct
when CONFIG_VSX is enabled.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

If we set the SPE MSR bit in save_user_regs we can blow away the VEC
bit.  This doesn't matter in reality as they are in fact the same bit
but looks bad.

Also, when we add VSX in a later patch, we need to be able to set two
separate MSR bits here.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Replace TIF_RESTORE_SIGMASK with TLF_RESTORE_SIGMASK and define
our own set_restore_sigmask() function.  This saves the costly
SMP-safe set_bit operation, which we do not need for the sigmask
flag since TIF_SIGPENDING always has to be set too.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>