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Commit a67ae758 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Michael Ellerman
Browse files

powerpc/ptrace: Enable support for Performance Monitor registers 



This patch enables support for Performance monitor registers related
ELF core note NT_PPC_PMU based ptrace requests through
PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved
through adding one new register sets REGSET_PMU in powerpc
corresponding to the ELF core note sections added in this
regard. It also implements the get, set and active functions
for this new register sets 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 cf89d4e1

arch/powerpc/include/uapi/asm/elf.h

+2 −1
Original line number Diff line number Diff line
@@ -95,6 +95,7 @@ 
#define ELF_NVSX	32	/* includes all VSX registers */

#define ELF_NTMSPRREG	3	/* include tfhar, tfiar, texasr */

#define ELF_NEBB	3	/* includes ebbrr, ebbhr, bescr */

#define ELF_NPMU	5	/* includes siar, sdar, sier, mmcr2, mmcr0 */



typedef unsigned long elf_greg_t64;

typedef elf_greg_t64 elf_gregset_t64[ELF_NGREG];

arch/powerpc/kernel/ptrace.c

+75 −0
Original line number Diff line number Diff line
@@ -1824,6 +1824,75 @@ static int ebb_set(struct task_struct *target, 


	return ret;

}

static int pmu_active(struct task_struct *target,

			 const struct user_regset *regset)

{

	if (!cpu_has_feature(CPU_FTR_ARCH_207S))

		return -ENODEV;



	return regset->n;

}



static int pmu_get(struct task_struct *target,

		      const struct user_regset *regset,

		      unsigned int pos, unsigned int count,

		      void *kbuf, void __user *ubuf)

{

	/* Build tests */

	BUILD_BUG_ON(TSO(siar) + sizeof(unsigned long) != TSO(sdar));

	BUILD_BUG_ON(TSO(sdar) + sizeof(unsigned long) != TSO(sier));

	BUILD_BUG_ON(TSO(sier) + sizeof(unsigned long) != TSO(mmcr2));

	BUILD_BUG_ON(TSO(mmcr2) + sizeof(unsigned long) != TSO(mmcr0));



	if (!cpu_has_feature(CPU_FTR_ARCH_207S))

		return -ENODEV;



	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,

			&target->thread.siar, 0,

			5 * sizeof(unsigned long));

}



static int pmu_set(struct task_struct *target,

		      const struct user_regset *regset,

		      unsigned int pos, unsigned int count,

		      const void *kbuf, const void __user *ubuf)

{

	int ret = 0;



	/* Build tests */

	BUILD_BUG_ON(TSO(siar) + sizeof(unsigned long) != TSO(sdar));

	BUILD_BUG_ON(TSO(sdar) + sizeof(unsigned long) != TSO(sier));

	BUILD_BUG_ON(TSO(sier) + sizeof(unsigned long) != TSO(mmcr2));

	BUILD_BUG_ON(TSO(mmcr2) + sizeof(unsigned long) != TSO(mmcr0));



	if (!cpu_has_feature(CPU_FTR_ARCH_207S))

		return -ENODEV;



	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

			&target->thread.siar, 0,

			sizeof(unsigned long));



	if (!ret)

		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

			&target->thread.sdar, sizeof(unsigned long),

			2 * sizeof(unsigned long));



	if (!ret)

		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

			&target->thread.sier, 2 * sizeof(unsigned long),

			3 * sizeof(unsigned long));



	if (!ret)

		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

			&target->thread.mmcr2, 3 * sizeof(unsigned long),

			4 * sizeof(unsigned long));



	if (!ret)

		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

			&target->thread.mmcr0, 4 * sizeof(unsigned long),

			5 * sizeof(unsigned long));

	return ret;

}

#endif

/*

 * These are our native regset flavors.
@@ -1857,6 +1926,7 @@ enum powerpc_regset { 
#ifdef CONFIG_PPC_BOOK3S_64

	REGSET_TAR,		/* TAR register */

	REGSET_EBB,		/* EBB registers */

	REGSET_PMR,		/* Performance Monitor Registers */

#endif

};
@@ -1957,6 +2027,11 @@ static const struct user_regset native_regsets[] = { 
		.size = sizeof(u64), .align = sizeof(u64),

		.active = ebb_active, .get = ebb_get, .set = ebb_set

	},

	[REGSET_PMR] = {

		.core_note_type = NT_PPC_PMU, .n = ELF_NPMU,

		.size = sizeof(u64), .align = sizeof(u64),

		.active = pmu_active, .get = pmu_get, .set = pmu_set

	},

#endif

};