powerpc: Extended ptrace interface
From: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Based on patches originally written by Torez Smith.
Add a new extended ptrace interface so that user-space has a single
interface for powerpc, without having to know the specific layout
of the debug registers.
Implement:
PPC_PTRACE_GETHWDEBUGINFO
PPC_PTRACE_SETHWDEBUG
PPC_PTRACE_DELHWDEBUG
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Acked-by: David Gibson <dwg@au1.ibm.com>
Cc: Torez Smith <lnxtorez@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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: Benjamin 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: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Acked-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On booke processors, gdb is seeing spurious SIGTRAPs when setting a
watchpoint.
user_disable_single_step() simply quits when the DAC is non-zero. It should
be clearing the DBCR0_IC and DBCR0_BT bits from the dbcr0 register and
TIF_SINGLESTEP from the thread flag.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reworked by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds block-step support on powerpc, including a PTRACE_SINGLEBLOCK
request for ptrace.
The BookE implementation is tweaked to fire a single step after a
block step in order to mimmic the server behaviour.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In PTRACE_GET/SETVSRREGS, we should be using the thread we are
ptracing rather than current.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fix cut-and-paste error in the size setting for ptrace buffers for VSX.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This changes powerpc syscall tracing to use the new tracehook.h entry
points. There is no change, only cleanup.
In addition, the assembly changes allow do_syscall_trace_enter() to
abort the syscall without losing the information about the original
r0 value.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 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 <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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 <luisgpm@br.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This correctly hooks the VSX dump into Roland McGrath core file
infrastructure. It adds the VSX dump information as an additional elf
note in the core file (after talking more to the tool chain/gdb guys).
This also ensures the formats are consistent between signals, ptrace
and core files.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul 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: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul 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: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We are going to change where the floating point registers are stored
in the thread_struct, so in preparation add some macros to access the
floating point registers. Update all code to use these new macros.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The PTRACE_SETREGS request was only recently added on powerpc,
and gdb does not use it. So it slipped through without getting
all the testing it should have had.
The user_regset changes had a simple bug in storing to all of
the 32-bit general registers block on 64-bit kernels. This bug
only comes up with PTRACE_SETREGS, not PPC_PTRACE_SETREGS.
It causes a BUG_ON to hit, so this fix needs to go in ASAP.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This makes the SPE register data appear in ELF core dumps, using the
new n_type value NT_PPC_SPE (0x101). This new note type is not used
by any consumers of core files yet, but support can be added. I don't
even have any hardware with SPE capabilities, so I've never seen such
a note. But this demonstrates how simple it is to export register
information in core dumps when the user_regset style is used for the
low-level code.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Now that ptrace_request handles these, we can drop some more boilerplate.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This replaces all the code for powerpc PTRACE_*REGS* requests with
simple calls to copy_regset_from_user and copy_regset_to_user. All
the ptrace formats are either the whole corresponding user_regset
format (core dump format) or a leading subset of it, so we can get
rid of all the remaining embedded knowledge of both those layouts
and of the internal data structures they correspond to. Only the
user_regset accessors need to implement that.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This extends task_user_regset_view CONFIG_PPC64 with support for the
32-bit view of register state, compatible with what a CONFIG_PPC32
kernel provides. This will enable generic machine-independent code to
access user-mode threads' registers for debugging and dumping.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This provides the task_user_regset_view entry point and support for
all the native-mode (64 on CONFIG_PPC64, 32 on CONFIG_PPC32) thread
register state. This will enable generic machine-independent code to
access user-mode threads' registers for debugging and dumping.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This implements user_regset-style accessors for the powerpc general
registers. In the future these functions will be the only place that
needs to understand the user_regset layout (core dump format) and how
it maps to the internal representation of user thread state.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This isolates the ptrace code for the special-case registers msr and trap
from the ptrace-layout dispatch code. This should inline away completely.
It cleanly separates the low-level machine magic that has to be done for
deep reasons, from the superficial details of the ptrace interface.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This implements user_regset-style accessors for the powerpc SPE data,
and rewrites the existing ptrace code in terms of those calls.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This implements user_regset-style accessors for the powerpc Altivec data,
and rewrites the existing ptrace code in terms of those calls.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This implements user_regset-style accessors for the powerpc FPU data,
and rewrites the existing ptrace code in terms of those calls.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This removes the handling for PTRACE_CONT et al from the powerpc
ptrace code, so it uses the new generic code via ptrace_request.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This defines the new standard arch_has_single_step macro. It makes the
existing set_single_step and clear_single_step entry points global, and
renames them to the new standard names user_enable_single_step and
user_disable_single_step, respectively.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Identical handlers of PTRACE_DETACH go into ptrace_request().
Not touching compat code.
Not touching archs that don't call ptrace_request.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This restores the CHECK_FULL_REGS sanity check to every place that can
access the nonvolatile GPRs for ptrace. This is already done for
native-bitwidth PTRACE_PEEKUSR, but was omitted for many other cases
(32-bit ptrace, PTRACE_GETREGS, etc.); I think there may have been more
uniform checks before that were lost in the recent cleanup of GETREGS et al.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make it so that SPE support can be determined at runtime. This is similiar
to how we handle AltiVec. This allows us to have SPE support built in and
work on processors with and without SPE.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Identical implementations of PTRACE_POKEDATA go into generic_ptrace_pokedata()
function.
AFAICS, fix bug on xtensa where successful PTRACE_POKEDATA will nevertheless
return EPERM.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow ptrace to set dabr in the thread structure for both 32 and 64 bits,
though only 64 bits actually uses that field, it's actually defined in both.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
One of the gratuitous difference between 32 and 64-bit ptrace is
whether you can whack the MSR:FE0 and FE1 bits from ptrace. This
patch forbids it unconditionally. In addition, the 64-bit kernels
used to return the exception mode in the MSR on reads, but 32-bit
kernels didn't. This patch makes it return those bits on both.
Finally, since ptrace-ppc32.h and ptrace-ppc64.h are mostly empty now, and
since the previous patch made ptrace32.c no longer need the MSR_DEBUGCHANGE
definition, we just remove those 2 files and move back the remaining bits
to ptrace.c (they were short lived heh ?).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch allows a ptracer to write to the "trap" and "orig_r3" words
of the pt_regs.
This, along with a subsequent patch to the signal restart code, should
enable gdb to properly handle syscall restarting after executing a separate
function (at least when there's no restart block).
This patch also removes ptrace32.c code toying directly with the registers
and makes it use the ptrace_get/put_reg() accessors for everything so that
the logic for checking what is permitted is in only one place.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
CHECK_FULL_REGS() exist on both 32 and 64 bits, so there's no need
to make it conditional on CONFIG_PPC32.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This folds back the ptrace-common.h bits back into ptrace.c and removes
that file. The FSL SPE bits from ptrace-ppc32.h are folded back in as
well.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The powerpc ptrace interface is dodgy at best. We have defined our
"own" versions of GETREGS/SETREGS/GETFPREGS/SETFPREGS that strangely
take arguments in reverse order from other archs (in addition to having
different request numbers) and have subtle issue, like not accessing
all of the registers in their respective categories.
This patch moves the implementation of those to a separate function
in order to facilitate their deprecation in the future, and provides
new ptrace requests that mirror the x86 and sparc ones and use the
same numbers:
PTRACE_GETREGS : returns an entire pt_regs (the whole thing,
not only the 32 GPRs, though that doesn't
include the FPRs etc... There's a compat version
for 32 bits that returns a 32 bits compatible
pt_regs (44 uints)
PTRACE_SETREGS : sets an entire pt_regs (the whole thing,
not only the 32 GPRs, though that doesn't
include the FPRs etc... Some registers cannot be
written to and will just be dropped, this is the
same as with POKEUSR, that is anything above MQ
on 32 bits and CCR on 64 bits. There is a compat
version as well.
PTRACE_GETFPREGS : returns all the FP registers -including- the FPSCR
that is 33 doubles (regardless of 32/64 bits)
PTRACE_SETFPREGS : sets all the FP registers -including- the FPSCR
that is 33 doubles (regardless of 32/64 bits)
And two that only exist on 64 bits kernels:
PTRACE_GETREGS64 : Same as PTRACE_GETREGS, except there is no compat
function, a 32 bits process will obtain the full 64
bits registers
PTRACE_SETREGS64 : Same as PTRACE_SETREGS, except there is no compat
function, a 32 bits process will set the full 64
bits registers
The two later ones makes things easier to have a 32 bits debugger on a
64 bits program (or on a 32 bits program that uses the full 64 bits of
the GPRs, which is possible though has issues that will be fixed in a
later patch).
Finally, while at it, the patch removes a whole bunch of code duplication
between ptrace32.c and ptrace.c, in large part by having the former call
into the later for all requests that don't need any special "compat"
treatment.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The powerpc ptrace code has some weirdness, like a ptrace-common.h file that
is actually ppc64 only and some of the 32 bits code ifdef'ed inside ptrace.c.
There are also separate implementations for things like get/set_vrregs for
32 and 64 bits which is totally unnecessary.
This patch cleans that up a bit by having a ptrace-common.h which contains
really common code (and makes a lot more code common), and ptrace-ppc32.h and
ptrace-ppc64.h files that contain the few remaining different bits.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The handling of PPC_PTRACE_GETFPREGS is broken on 32 bits kernel,
it will only return half of the registers. Since that call didn't
initially exist for 32 bits kernel (added recently), rather than
fixing it, let's just remove it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The ppc32 kernel didn't properly set/clear the TIF_SINGLESTEP
flag, causing return from syscalls to not SIGTRAP, thus executing
one more instruction before stopping again.
This fixes it. The ptrace code is a bit of a mess, and is overdue
for at least a -proper- 32/64 bits split and possibly more cleanups
but this minimum fix should be ok for 2.6.22
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.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: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The system call entry code will clear the high bits of argument
registers before invoking the system call; don't report whatever noise
happens to be in the high bits of the register before that happens.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The secure_computing() call which automatically aborts a process if it
tries to execute a syscall it shouldn't is much more useful if we
actually do it _before_ the syscall, rather than afterwards. PPC64 got
this right, but the original incorrect behaviour inherited from arch/ppc
was preserved by ifdefs. Make it the same on PPC32 too.
Also, I see no need to export do_syscall_trace_{leave,enter} on ppc32 --
they were only exported because the old do_syscall_trace() (which they
replaced) used to be.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Due to my stupidity, we were checking for the wrong bit in CCR when
attempting to determine whether a syscall succeeded or not. Remedy the
symptom, if not the cause.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
I have tested PPC_PTRACE_GETREGS and PPC_PTRACE_SETREGS on umview.
I do not understand why historically these tags has been defined as
PPC_PTRACE_GETREGS and PPC_PTRACE_SETREGS instead of simply
PTRACE_[GS]ETREGS. The other "originality" is that the address must be
put into the "addr" field instead of the "data" field as stated in the
manual.
Signed-off-by: renzo davoli <renzo@cs.unibo.it>
Signed-off-by: Paul Mackerras <paulus@samba.org>
A careful reading of the recent changes to the system call entry/exit
paths revealed several problems, plus some things that could be
simplified and improved:
* 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit
path, so it was only doing anything with it once it saw some other
bit being set. In other words, the noerror behaviour would apply to
the next system call where we had to reschedule or deliver a signal,
which is not necessarily the current system call.
* 32-bit wasn't doing the call to ptrace_notify in the syscall exit
path when the _TIF_SINGLESTEP bit was set.
* _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and
_TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set
by system calls. I took it out of _TIF_USER_WORK_MASK.
* On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers
to be restored (unless perhaps a signal was delivered or the syscall
was traced or single-stepped). Thus the non-volatile registers
weren't restored on exit from a signal handler. We probably got
away with it mostly because signal handlers written in C wouldn't
alter the non-volatile registers.
* On 32-bit I simplified the code and made it more like 64-bit by
making the syscall exit path jump to ret_from_except to handle
preemption and signal delivery.
* 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was
set - but I think because of that 32-bit was actually restoring the
non-volatile registers on exit from a signal handler.
* I changed the order of enabling interrupts and saving the
non-volatile registers before calling do_syscall_trace_leave; now we
enable interrupts first.
Signed-off-by: Paul Mackerras <paulus@samba.org>
The sys_ptrace boilerplate code (everything outside the big switch
statement for the arch-specific requests) is shared by most architectures.
This patch moves it to kernel/ptrace.c and leaves the arch-specific code as
arch_ptrace.
Some architectures have a too different ptrace so we have to exclude them.
They continue to keep their implementations. For sh64 I had to add a
sh64_ptrace wrapper because it does some initialization on the first call.
For um I removed an ifdefed SUBARCH_PTRACE_SPECIAL block, but
SUBARCH_PTRACE_SPECIAL isn't defined anywhere in the tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-By: David Howells <dhowells@redhat.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
