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Commit 19cbcbf7 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Michael Ellerman
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powerpc/ptrace: Enable support for NT_PPC_CFPR 



This patch enables support for TM checkpointed FPR register
set ELF core note NT_PPC_CFPR based ptrace requests through
PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved
through adding a register set REGSET_CFPR in powerpc
corresponding to the ELF core note section added. It
implements the get, set and active functions for this new
register set added.

Signed-off-by: default avatarAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: default avatarSimon Guo <wei.guo.simon@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 25847fb1

arch/powerpc/kernel/ptrace.c

+126 −0
Original line number Diff line number Diff line
@@ -1032,6 +1032,121 @@ static int tm_cgpr_set(struct task_struct *target, 


	return ret;

}



/**

 * tm_cfpr_active - get active number of registers in CFPR

 * @target:	The target task.

 * @regset:	The user regset structure.

 *

 * This function checks for the active number of available

 * regisers in transaction checkpointed FPR category.

 */

static int tm_cfpr_active(struct task_struct *target,

				const struct user_regset *regset)

{

	if (!cpu_has_feature(CPU_FTR_TM))

		return -ENODEV;



	if (!MSR_TM_ACTIVE(target->thread.regs->msr))

		return 0;



	return regset->n;

}



/**

 * tm_cfpr_get - get CFPR registers

 * @target:	The target task.

 * @regset:	The user regset structure.

 * @pos:	The buffer position.

 * @count:	Number of bytes to copy.

 * @kbuf:	Kernel buffer to copy from.

 * @ubuf:	User buffer to copy into.

 *

 * This function gets in transaction checkpointed FPR registers.

 *

 * When the transaction is active 'fp_state' holds the checkpointed

 * values for the current transaction to fall back on if it aborts

 * in between. This function gets those checkpointed FPR registers.

 * The userspace interface buffer layout is as follows.

 *

 * struct data {

 *	u64	fpr[32];

 *	u64	fpscr;

 *};

 */

static int tm_cfpr_get(struct task_struct *target,

			const struct user_regset *regset,

			unsigned int pos, unsigned int count,

			void *kbuf, void __user *ubuf)

{

	u64 buf[33];

	int i;



	if (!cpu_has_feature(CPU_FTR_TM))

		return -ENODEV;



	if (!MSR_TM_ACTIVE(target->thread.regs->msr))

		return -ENODATA;



	flush_fp_to_thread(target);

	flush_altivec_to_thread(target);

	flush_tmregs_to_thread(target);



	/* copy to local buffer then write that out */

	for (i = 0; i < 32 ; i++)

		buf[i] = target->thread.TS_FPR(i);

	buf[32] = target->thread.fp_state.fpscr;

	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, buf, 0, -1);

}



/**

 * tm_cfpr_set - set CFPR registers

 * @target:	The target task.

 * @regset:	The user regset structure.

 * @pos:	The buffer position.

 * @count:	Number of bytes to copy.

 * @kbuf:	Kernel buffer to copy into.

 * @ubuf:	User buffer to copy from.

 *

 * This function sets in transaction checkpointed FPR registers.

 *

 * When the transaction is active 'fp_state' holds the checkpointed

 * FPR register values for the current transaction to fall back on

 * if it aborts in between. This function sets these checkpointed

 * FPR registers. The userspace interface buffer layout is as follows.

 *

 * struct data {

 *	u64	fpr[32];

 *	u64	fpscr;

 *};

 */

static int tm_cfpr_set(struct task_struct *target,

			const struct user_regset *regset,

			unsigned int pos, unsigned int count,

			const void *kbuf, const void __user *ubuf)

{

	u64 buf[33];

	int i;



	if (!cpu_has_feature(CPU_FTR_TM))

		return -ENODEV;



	if (!MSR_TM_ACTIVE(target->thread.regs->msr))

		return -ENODATA;



	flush_fp_to_thread(target);

	flush_altivec_to_thread(target);

	flush_tmregs_to_thread(target);



	/* copy to local buffer then write that out */

	i = user_regset_copyin(&pos, &count, &kbuf, &ubuf, buf, 0, -1);

	if (i)

		return i;

	for (i = 0; i < 32 ; i++)

		target->thread.TS_FPR(i) = buf[i];

	target->thread.fp_state.fpscr = buf[32];

	return 0;

}

#endif



/*
@@ -1051,6 +1166,7 @@ enum powerpc_regset { 
#endif

#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

	REGSET_TM_CGPR,		/* TM checkpointed GPR registers */

	REGSET_TM_CFPR,		/* TM checkpointed FPR registers */

#endif

};
@@ -1092,6 +1208,11 @@ static const struct user_regset native_regsets[] = { 
		.size = sizeof(long), .align = sizeof(long),

		.active = tm_cgpr_active, .get = tm_cgpr_get, .set = tm_cgpr_set

	},

	[REGSET_TM_CFPR] = {

		.core_note_type = NT_PPC_TM_CFPR, .n = ELF_NFPREG,

		.size = sizeof(double), .align = sizeof(double),

		.active = tm_cfpr_active, .get = tm_cfpr_get, .set = tm_cfpr_set

	},

#endif

};
@@ -1324,6 +1445,11 @@ static const struct user_regset compat_regsets[] = { 
		.active = tm_cgpr_active,

		.get = tm_cgpr32_get, .set = tm_cgpr32_set

	},

	[REGSET_TM_CFPR] = {

		.core_note_type = NT_PPC_TM_CFPR, .n = ELF_NFPREG,

		.size = sizeof(double), .align = sizeof(double),

		.active = tm_cfpr_active, .get = tm_cfpr_get, .set = tm_cfpr_set

	},

#endif

};