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[POWERPC] ptrace shouldn't touch FP exec mode

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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 commit is contained in:
Benjamin Herrenschmidt
2007-06-04 15:15:47 +10:00
committed by Paul Mackerras
parent 912000e73e
commit abd0650541
4 changed files with 40 additions and 95 deletions
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47
arch/powerpc/kernel/ptrace.c
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@@ -35,17 +35,29 @@
#include <asm/pgtable.h>
#include <asm/system.h>
#ifdef CONFIG_PPC64
#include "ptrace-ppc64.h"
#else
#include "ptrace-ppc32.h"
#endif
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* Set of msr bits that gdb can change on behalf of a process.
*/
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
#define MSR_DEBUGCHANGE 0
#else
#define MSR_DEBUGCHANGE (MSR_SE | MSR_BE)
#endif
/*
* Max register writeable via put_reg
*/
#ifdef CONFIG_PPC32
#define PT_MAX_PUT_REG PT_MQ
#else
#define PT_MAX_PUT_REG PT_CCR
#endif
/*
* Get contents of register REGNO in task TASK.
*/
@@ -58,7 +70,7 @@ unsigned long ptrace_get_reg(struct task_struct *task, int regno)
if (regno == PT_MSR) {
tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
return PT_MUNGE_MSR(tmp, task);
return tmp | task->thread.fpexc_mode;
}
if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
@@ -274,6 +286,27 @@ static void clear_single_step(struct task_struct *task)
clear_tsk_thread_flag(task, TIF_SINGLESTEP);
}
#ifdef CONFIG_PPC64
static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
unsigned long data)
{
/* We only support one DABR and no IABRS at the moment */
if (addr > 0)
return -EINVAL;
/* The bottom 3 bits are flags */
if ((data & ~0x7UL) >= TASK_SIZE)
return -EIO;
/* Ensure translation is on */
if (data && !(data & DABR_TRANSLATION))
return -EIO;
task->thread.dabr = data;
return 0;
}
#endif
/*
* Called by kernel/ptrace.c when detaching..
*