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Commit 1ffa11ab authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
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s390/kprobes: allow kprobes only on known instructions 



Since we have an in-kernel disassembler we can make sure that
there won't be any kprobes set on random data.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent a882b3b0

arch/s390/include/asm/dis.h

+6 −0
Original line number Diff line number Diff line
@@ -42,5 +42,11 @@ static inline int insn_length(unsigned char code) 
void show_code(struct pt_regs *regs);

void print_fn_code(unsigned char *code, unsigned long len);

int insn_to_mnemonic(unsigned char *instruction, char *buf, unsigned int len);

struct s390_insn *find_insn(unsigned char *code);



static inline int is_known_insn(unsigned char *code)

{

	return !!find_insn(code);

}



#endif /* __ASM_S390_DIS_H__ */

arch/s390/kernel/dis.c

+1 −1
Original line number Diff line number Diff line
@@ -1586,7 +1586,7 @@ static unsigned int extract_operand(unsigned char *code, 
	return val;

}



static struct s390_insn *find_insn(unsigned char *code)

struct s390_insn *find_insn(unsigned char *code)

{

	unsigned char opfrag = code[1];

	unsigned char opmask;

arch/s390/kernel/kprobes.c

+2 −0
Original line number Diff line number Diff line
@@ -60,6 +60,8 @@ struct kprobe_insn_cache kprobe_dmainsn_slots = { 


static int __kprobes is_prohibited_opcode(kprobe_opcode_t *insn)

{

	if (!is_known_insn((unsigned char *)insn))

		return -EINVAL;

	switch (insn[0] >> 8) {

	case 0x0c:	/* bassm */

	case 0x0b:	/* bsm	 */