linux-stable.git/Documentation/powerpc, branch linux-3.9.y

powerpc/tm: Abort on emulation and alignment faults

2013-06-07T19:53:20+00:00

commit 6ce6c629fd8254b3177650de99699682ff7f6707 upstream.

If we are emulating an instruction inside an active user transaction that
touches memory, the kernel can't emulate it as it operates in transactional
suspend context.  We need to abort these transactions and send them back to
userspace for the hardware to rollback.

We can service these if the user transaction is in suspend mode, since the
kernel will operate in the same suspend context.

This adds a check to all alignment faults and to specific instruction
emulations (only string instructions for now).  If the user process is in an
active (non-suspended) transaction, we abort the transaction go back to
userspace allowing the HW to roll back the transaction and tell the user of the
failure.  This also adds new tm abort cause codes to report the reason of the
persistent error to the user.

Crappy test case here http://neuling.org/devel/junkcode/aligntm.c

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Fix userspace stack corruption on signal delivery for active transactions

2013-06-07T19:53:19+00:00

commit 2b3f8e87cf99a33fb6faf5026d7147748bbd77b6 upstream.

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: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Update cause codes documentation

2013-06-07T19:53:19+00:00

commit 24b92375dc4ec8a15262e8aaaab60b7404d4b1e7 upstream.

Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Documentation for transactional memory on powerpc

2013-02-15T06:02:25+00:00

Signed-off-by: Matt Evans 
Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt

Documentation/powerpc: Fix path to the powerpc directory

2013-01-10T06:01:50+00:00

ppc -> powerpc

Signed-off-by: Thomas Waldecker 
Signed-off-by: Benjamin Herrenschmidt

powerpc/hw-breakpoint: Use generic hw-breakpoint interfaces for new PPC ptrace flags

2012-11-15T02:00:23+00:00

PPC_PTRACE_GETHWDBGINFO, PPC_PTRACE_SETHWDEBUG and PPC_PTRACE_DELHWDEBUG are
PowerPC specific ptrace flags that use the watchpoint register. While they are
targeted primarily towards BookE users, user-space applications such as GDB
have started using them for BookS too. This patch enables the use of generic
hardware breakpoint interfaces for these new flags.

Apart from the usual benefits of using generic hw-breakpoint interfaces, these
changes allow debuggers (such as GDB) to use a common set of ptrace flags for
their watchpoint needs and allow more precise breakpoint specification (length
of the variable can be specified).

Mikey added: rebased and added dbginfo.features around #ifdef
             CONFIG_HAVE_HW_BREAKPOINT

Signed-off-by: K.Prasad 
Acked-by: David Gibson 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Neuling 
Signed-off-by: Benjamin Herrenschmidt

Documentation/powerpc/mpc52xx.txt: Checkpatch cleanup

2012-03-18T22:59:34+00:00

Fix all trailing whitespace errors reported by checkpatch.

Signed-off-by: Andrea Gelmini 
Signed-off-by: Anatolij Gustschin

fadump: Remove the phyp assisted dump code.

2012-02-22T23:50:03+00:00

Remove the phyp assisted dump implementation which is not is use.

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt

fadump: Add documentation for firmware-assisted dump.

2012-02-22T23:50:00+00:00

Documentation for firmware-assisted dump. This document is based on the
original documentation written for phyp assisted dump by Linas Vepstas
and Manish Ahuja, with few changes to reflect the current implementation.

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi