Commit abd06505 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Paul Mackerras
Browse files

[POWERPC] ptrace shouldn't touch FP exec mode 



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: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 912000e7

arch/powerpc/kernel/ptrace-ppc32.h

deleted100644 → 0
+0 −35
Original line number Diff line number Diff line 
/*

 *    Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration

 *    Extracted from ptrace.c and ptrace32.c

 *

 * This file is subject to the terms and conditions of the GNU General

 * Public License.  See the file README.legal in the main directory of

 * this archive for more details.

 */



#ifndef _POWERPC_PTRACE_PPC32_H

#define _POWERPC_PTRACE_PPC32_H



/*

 * 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

 */

#define PT_MAX_PUT_REG	PT_MQ



/*

 * Munging of MSR on return from get_regs

 *

 * Nothing to do on ppc32

 */

#define PT_MUNGE_MSR(msr, task)	(msr)





#endif /* _POWERPC_PTRACE_PPC32_H */

arch/powerpc/kernel/ptrace-ppc64.h

deleted100644 → 0
+0 −51
Original line number Diff line number Diff line 
/*

 *    Copyright (c) 2002 Stephen Rothwell, IBM Coproration

 *    Extracted from ptrace.c and ptrace32.c

 *

 * This file is subject to the terms and conditions of the GNU General

 * Public License.  See the file README.legal in the main directory of

 * this archive for more details.

 */



#ifndef _POWERPC_PTRACE_PPC64_H

#define _POWERPC_PTRACE_PPC64_H



/*

 * Set of msr bits that gdb can change on behalf of a process.

 */

#define MSR_DEBUGCHANGE	(MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1)



/*

 * Max register writeable via put_reg

 */

#define PT_MAX_PUT_REG	PT_CCR



/*

 * Munging of MSR on return from get_regs

 *

 * Put the correct FP bits in, they might be wrong as a result

 * of our lazy FP restore.

 */



#define PT_MUNGE_MSR(msr, task)	({ (msr) | (task)->thread.fpexc_mode; })



static inline 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 /* _POWERPC_PTRACE_PPC64_H */

arch/powerpc/kernel/ptrace.c

+39 −6
Original line number Diff line number Diff line
@@ -35,16 +35,28 @@ 
#include <asm/pgtable.h>

#include <asm/system.h>



#ifdef CONFIG_PPC64

#include "ptrace-ppc64.h"

/*

 * 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

#include "ptrace-ppc32.h"

#define MSR_DEBUGCHANGE	(MSR_SE | MSR_BE)

#endif



/*

 * does not yet catch signals sent when the child dies.

 * in exit.c or in signal.c.

 * 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..

 *

arch/powerpc/kernel/ptrace32.c

+0 −2
Original line number Diff line number Diff line
@@ -33,8 +33,6 @@ 
#include <asm/pgtable.h>

#include <asm/system.h>



#include "ptrace-ppc64.h"



/*

 * does not yet catch signals sent when the child dies.

 * in exit.c or in signal.c.

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