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>
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 ptrace_get_task_struct() helper that I added as part of the ptrace
consolidation is useful in variety of places that currently opencode it.
Switch them to the common helpers.
Add a ptrace_traceme() helper that needs to be explicitly called, and simplify
the ptrace_get_task_struct() interface. We don't need the request argument
now, and we return the task_struct directly, using ERR_PTR() for error
returns. It's a bit more code in the callers, but we have two sane routines
that do one thing well now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
