linux-toradex.git/arch/powerpc/kernel/signal.c, branch v3.2.34

powerpc: fix double syscall restarts

2010-09-22T16:33:50+00:00

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: Al Viro 
Acked-by: Paul Mackerras 
Signed-off-by: Linus Torvalds

powerpc, hw_breakpoint: Enable hw-breakpoints while handling intervening signals

2010-06-22T09:40:50+00:00

A signal delivered between a hw_breakpoint_handler() and the
single_step_dabr_instruction() will not have the breakpoint active
while the signal handler is running -- the signal delivery will
set up a new MSR value which will not have MSR_SE set, so we
won't get the signal step interrupt until and unless the signal
handler returns (which it may never do).

To fix this, we restore the breakpoint when delivering a signal --
we clear the MSR_SE bit and set the DABR again.  If the signal
handler returns, the DABR interrupt will occur again when the
instruction that we were originally trying to single-step gets
re-executed.

[Paul Mackerras  pointed out the need to do this.]

Signed-off-by: K.Prasad 
Signed-off-by: Paul Mackerras

powerpc/booke: Add support for advanced debug registers

2010-02-17T03:03:17+00:00

powerpc/booke: Add support for advanced debug registers

From: Dave Kleikamp 

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: Dave Kleikamp 
Cc: Torez Smith  
Cc: Benjamin Herrenschmidt 
Cc: David Gibson 
Cc: Josh Boyer 
Cc: Kumar Gala 
Cc: Sergio Durigan Junior 
Cc: Thiago Jung Bauermann 
Cc: linuxppc-dev list 
Signed-off-by: Benjamin Herrenschmidt

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

2010-02-17T03:03:16+00:00

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

From: Dave Kleikamp 

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: Dave Kleikamp 
Acked-by: David Gibson 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Sanitize stack pointer in signal handling code

2009-03-27T05:58:24+00:00

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: Josh Boyer 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Add TIF_NOTIFY_RESUME support for tracehook

2008-07-28T06:30:50+00:00

This adds TIF_NOTIFY_RESUME support for powerpc.  When set,
we call tracehook_notify_resume() on the way to user mode.
This overloads do_signal() to do the work, but changes its
arguments to it has the TIF_* bits handy in a register and
drops the useless first argument that was always zero.

Signed-off-by: Roland McGrath 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Call tracehook_signal_handler() when setting up signal frames

2008-07-28T06:30:49+00:00

This makes the powerpc signal handling code call tracehook_signal_handler()
after a handler is set up.  This means that using PTRACE_SINGLESTEP to
enter a signal handler will report to ptrace on the first instruction of
the handler, instead of the second.  This is consistent with what x86 and
other machines do, and what users and debuggers want.

BenH: Fixed up the test for the trap value.

Signed-off-by: Roland McGrath 
Signed-off-by: Benjamin Herrenschmidt

powerpc/booke: Clean up the hardware watchpoint support

2008-07-28T06:30:47+00:00

* CONFIG_BOOKE is selected by CONFIG_44x so we dont need both
* Fixed a few comments
* Go back to only using DBCR0_IDM to determine if we are using
  debug resources.

Signed-off-by: Kumar Gala 
Signed-off-by: Benjamin Herrenschmidt

powerpc: BookE hardware watchpoint support

2008-07-25T05:44:39+00:00

This patch implements support for HW based watchpoint via the
DBSR_DAC (Data Address Compare) facility of the BookE processors.

It does so by interfacing with the existing DABR breakpoint code
and adding the necessary bits and pieces for the new bits to
be properly set or cleared

Signed-off-by: Luis Machado 
Signed-off-by: Benjamin Herrenschmidt

[POWERPC] Define and use TLF_RESTORE_SIGMASK

2008-05-14T12:31:33+00:00

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: Roland McGrath 
Signed-off-by: Paul Mackerras