Commit 650b55b7 authored by Jordan Niethe's avatar Jordan Niethe Committed by Michael Ellerman
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powerpc: Add prefixed instructions to instruction data type 



For powerpc64, redefine the ppc_inst type so both word and prefixed
instructions can be represented. On powerpc32 the type will remain the
same. Update places which had assumed instructions to be 4 bytes long.

Signed-off-by: default avatarJordan Niethe <jniethe5@gmail.com>
Reviewed-by: default avatarAlistair Popple <alistair@popple.id.au>
[mpe: Rework the get_user_inst() macros to be parameterised, and don't
      assign to the dest if an error occurred. Use CONFIG_PPC64 not
      __powerpc64__ in a few places. Address other comments from
      Christophe. Fix some sparse complaints.]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-24-jniethe5@gmail.com
parent 7a8818e0

arch/powerpc/include/asm/inst.h

+64 −6
Original line number Diff line number Diff line
@@ -2,29 +2,80 @@ 
#ifndef _ASM_POWERPC_INST_H

#define _ASM_POWERPC_INST_H



#include <asm/ppc-opcode.h>



/*

 * Instruction data type for POWER

 */



struct ppc_inst {

	u32 val;

#ifdef CONFIG_PPC64

	u32 suffix;

#endif

} __packed;



#define ppc_inst(x) ((struct ppc_inst){ .val = x })



static inline u32 ppc_inst_val(struct ppc_inst x)

{

	return x.val;

}



static inline int ppc_inst_len(struct ppc_inst x)

static inline int ppc_inst_primary_opcode(struct ppc_inst x)

{

	return sizeof(struct ppc_inst);

	return ppc_inst_val(x) >> 26;

}



static inline int ppc_inst_primary_opcode(struct ppc_inst x)

#ifdef CONFIG_PPC64

#define ppc_inst(x) ((struct ppc_inst){ .val = (x), .suffix = 0xff })



#define ppc_inst_prefix(x, y) ((struct ppc_inst){ .val = (x), .suffix = (y) })



static inline u32 ppc_inst_suffix(struct ppc_inst x)

{

	return ppc_inst_val(x) >> 26;

	return x.suffix;

}



static inline bool ppc_inst_prefixed(struct ppc_inst x)

{

	return (ppc_inst_primary_opcode(x) == 1) && ppc_inst_suffix(x) != 0xff;

}



static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)

{

	return ppc_inst_prefix(swab32(ppc_inst_val(x)),

			       swab32(ppc_inst_suffix(x)));

}



static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr)

{

	u32 val, suffix;



	val = *(u32 *)ptr;

	if ((val >> 26) == OP_PREFIX) {

		suffix = *((u32 *)ptr + 1);

		return ppc_inst_prefix(val, suffix);

	} else {

		return ppc_inst(val);

	}

}



static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y)

{

	return *(u64 *)&x == *(u64 *)&y;

}



#else



#define ppc_inst(x) ((struct ppc_inst){ .val = x })



static inline bool ppc_inst_prefixed(struct ppc_inst x)

{

	return false;

}



static inline u32 ppc_inst_suffix(struct ppc_inst x)

{

	return 0;

}



static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x)
@@ -42,6 +93,13 @@ static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y) 
	return ppc_inst_val(x) == ppc_inst_val(y);

}



#endif /* CONFIG_PPC64 */



static inline int ppc_inst_len(struct ppc_inst x)

{

	return ppc_inst_prefixed(x) ? 8 : 4;

}



int probe_user_read_inst(struct ppc_inst *inst,

			 struct ppc_inst __user *nip);

arch/powerpc/include/asm/kprobes.h

+1 −1
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ extern kprobe_opcode_t optprobe_template_ret[]; 
extern kprobe_opcode_t optprobe_template_end[];



/* Fixed instruction size for powerpc */

#define MAX_INSN_SIZE		1

#define MAX_INSN_SIZE		2

#define MAX_OPTIMIZED_LENGTH	sizeof(kprobe_opcode_t)	/* 4 bytes */

#define MAX_OPTINSN_SIZE	(optprobe_template_end - optprobe_template_entry)

#define RELATIVEJUMP_SIZE	sizeof(kprobe_opcode_t)	/* 4 bytes */

arch/powerpc/include/asm/ppc-opcode.h

+3 −0
Original line number Diff line number Diff line
@@ -158,6 +158,9 @@ 
/* VMX Vector Store Instructions */

#define OP_31_XOP_STVX          231



/* Prefixed Instructions */

#define OP_PREFIX		1



#define OP_31   31

#define OP_LWZ  32

#define OP_STFS 52

arch/powerpc/include/asm/uaccess.h

+36 −0
Original line number Diff line number Diff line
@@ -105,6 +105,40 @@ static inline int __access_ok(unsigned long addr, unsigned long size, 
#define __put_user_inatomic(x, ptr) \

	__put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))



#ifdef CONFIG_PPC64



#define ___get_user_instr(gu_op, dest, ptr)				\

({									\

	long __gui_ret = 0;						\

	unsigned long __gui_ptr = (unsigned long)ptr;			\

	struct ppc_inst __gui_inst;					\

	unsigned int __prefix, __suffix;				\

	__gui_ret = gu_op(__prefix, (unsigned int __user *)__gui_ptr);	\

	if (__gui_ret == 0) {						\

		if ((__prefix >> 26) == OP_PREFIX) {			\

			__gui_ret = gu_op(__suffix,			\

				(unsigned int __user *)__gui_ptr + 1);	\

			__gui_inst = ppc_inst_prefix(__prefix,		\

						     __suffix);		\

		} else {						\

			__gui_inst = ppc_inst(__prefix);		\

		}							\

		if (__gui_ret == 0)					\

			(dest) = __gui_inst;				\

	}								\

	__gui_ret;							\

})



#define get_user_instr(x, ptr) \

	___get_user_instr(get_user, x, ptr)



#define __get_user_instr(x, ptr) \

	___get_user_instr(__get_user, x, ptr)



#define __get_user_instr_inatomic(x, ptr) \

	___get_user_instr(__get_user_inatomic, x, ptr)



#else /* !CONFIG_PPC64 */

#define get_user_instr(x, ptr) \

	get_user((x).val, (u32 __user *)(ptr))
@@ -114,6 +148,8 @@ static inline int __access_ok(unsigned long addr, unsigned long size, 
#define __get_user_instr_inatomic(x, ptr) \

	__get_user_nosleep((x).val, (u32 __user *)(ptr), sizeof(u32))



#endif /* CONFIG_PPC64 */



extern long __put_user_bad(void);



/*

arch/powerpc/include/asm/uprobes.h

+1 −1
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ 


typedef ppc_opcode_t uprobe_opcode_t;



#define MAX_UINSN_BYTES		4

#define MAX_UINSN_BYTES		8

#define UPROBE_XOL_SLOT_BYTES	(MAX_UINSN_BYTES)



/* The following alias is needed for reference from arch-agnostic code */