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Commit 975fab17 authored by Jan Willeke's avatar Jan Willeke Committed by Martin Schwidefsky
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s390/uprobes: common library for kprobes and uprobes 



This patch moves common functions from kprobes.c to probes.c.
Thus its possible for uprobes to use them without enabling kprobes.

Signed-off-by: default avatarJan Willeke <willeke@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent bbae71bf

arch/s390/include/asm/kprobes.h

+4 −0
Original line number Diff line number Diff line
@@ -84,6 +84,10 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr); 
int kprobe_exceptions_notify(struct notifier_block *self,

	unsigned long val, void *data);



int probe_is_prohibited_opcode(u16 *insn);

int probe_get_fixup_type(u16 *insn);

int probe_is_insn_relative_long(u16 *insn);



#define flush_insn_slot(p)	do { } while (0)



#endif	/* _ASM_S390_KPROBES_H */

arch/s390/kernel/kprobes.c

+3 −151
Original line number Diff line number Diff line
@@ -58,161 +58,13 @@ struct kprobe_insn_cache kprobe_dmainsn_slots = { 
	.insn_size = MAX_INSN_SIZE,

};



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	 */

	case 0x83:	/* diag  */

	case 0x44:	/* ex	 */

	case 0xac:	/* stnsm */

	case 0xad:	/* stosm */

		return -EINVAL;

	case 0xc6:

		switch (insn[0] & 0x0f) {

		case 0x00: /* exrl   */

			return -EINVAL;

		}

	}

	switch (insn[0]) {

	case 0x0101:	/* pr	 */

	case 0xb25a:	/* bsa	 */

	case 0xb240:	/* bakr  */

	case 0xb258:	/* bsg	 */

	case 0xb218:	/* pc	 */

	case 0xb228:	/* pt	 */

	case 0xb98d:	/* epsw	 */

		return -EINVAL;

	}

	return 0;

}



static int __kprobes get_fixup_type(kprobe_opcode_t *insn)

{

	/* default fixup method */

	int fixup = FIXUP_PSW_NORMAL;



	switch (insn[0] >> 8) {

	case 0x05:	/* balr	*/

	case 0x0d:	/* basr */

		fixup = FIXUP_RETURN_REGISTER;

		/* if r2 = 0, no branch will be taken */

		if ((insn[0] & 0x0f) == 0)

			fixup |= FIXUP_BRANCH_NOT_TAKEN;

		break;

	case 0x06:	/* bctr	*/

	case 0x07:	/* bcr	*/

		fixup = FIXUP_BRANCH_NOT_TAKEN;

		break;

	case 0x45:	/* bal	*/

	case 0x4d:	/* bas	*/

		fixup = FIXUP_RETURN_REGISTER;

		break;

	case 0x47:	/* bc	*/

	case 0x46:	/* bct	*/

	case 0x86:	/* bxh	*/

	case 0x87:	/* bxle	*/

		fixup = FIXUP_BRANCH_NOT_TAKEN;

		break;

	case 0x82:	/* lpsw	*/

		fixup = FIXUP_NOT_REQUIRED;

		break;

	case 0xb2:	/* lpswe */

		if ((insn[0] & 0xff) == 0xb2)

			fixup = FIXUP_NOT_REQUIRED;

		break;

	case 0xa7:	/* bras	*/

		if ((insn[0] & 0x0f) == 0x05)

			fixup |= FIXUP_RETURN_REGISTER;

		break;

	case 0xc0:

		if ((insn[0] & 0x0f) == 0x05)	/* brasl */

			fixup |= FIXUP_RETURN_REGISTER;

		break;

	case 0xeb:

		switch (insn[2] & 0xff) {

		case 0x44: /* bxhg  */

		case 0x45: /* bxleg */

			fixup = FIXUP_BRANCH_NOT_TAKEN;

			break;

		}

		break;

	case 0xe3:	/* bctg	*/

		if ((insn[2] & 0xff) == 0x46)

			fixup = FIXUP_BRANCH_NOT_TAKEN;

		break;

	case 0xec:

		switch (insn[2] & 0xff) {

		case 0xe5: /* clgrb */

		case 0xe6: /* cgrb  */

		case 0xf6: /* crb   */

		case 0xf7: /* clrb  */

		case 0xfc: /* cgib  */

		case 0xfd: /* cglib */

		case 0xfe: /* cib   */

		case 0xff: /* clib  */

			fixup = FIXUP_BRANCH_NOT_TAKEN;

			break;

		}

		break;

	}

	return fixup;

}



static int __kprobes is_insn_relative_long(kprobe_opcode_t *insn)

{

	/* Check if we have a RIL-b or RIL-c format instruction which

	 * we need to modify in order to avoid instruction emulation. */

	switch (insn[0] >> 8) {

	case 0xc0:

		if ((insn[0] & 0x0f) == 0x00) /* larl */

			return true;

		break;

	case 0xc4:

		switch (insn[0] & 0x0f) {

		case 0x02: /* llhrl  */

		case 0x04: /* lghrl  */

		case 0x05: /* lhrl   */

		case 0x06: /* llghrl */

		case 0x07: /* sthrl  */

		case 0x08: /* lgrl   */

		case 0x0b: /* stgrl  */

		case 0x0c: /* lgfrl  */

		case 0x0d: /* lrl    */

		case 0x0e: /* llgfrl */

		case 0x0f: /* strl   */

			return true;

		}

		break;

	case 0xc6:

		switch (insn[0] & 0x0f) {

		case 0x02: /* pfdrl  */

		case 0x04: /* cghrl  */

		case 0x05: /* chrl   */

		case 0x06: /* clghrl */

		case 0x07: /* clhrl  */

		case 0x08: /* cgrl   */

		case 0x0a: /* clgrl  */

		case 0x0c: /* cgfrl  */

		case 0x0d: /* crl    */

		case 0x0e: /* clgfrl */

		case 0x0f: /* clrl   */

			return true;

		}

		break;

	}

	return false;

}



static void __kprobes copy_instruction(struct kprobe *p)

{

	s64 disp, new_disp;

	u64 addr, new_addr;



	memcpy(p->ainsn.insn, p->addr, insn_length(p->opcode >> 8));

	if (!is_insn_relative_long(p->ainsn.insn))

	if (!probe_is_insn_relative_long(p->ainsn.insn))

		return;

	/*

	 * For pc-relative instructions in RIL-b or RIL-c format patch the
@@ -276,7 +128,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) 
	if ((unsigned long) p->addr & 0x01)

		return -EINVAL;

	/* Make sure the probe isn't going on a difficult instruction */

	if (is_prohibited_opcode(p->addr))

	if (probe_is_prohibited_opcode(p->addr))

		return -EINVAL;

	if (s390_get_insn_slot(p))

		return -ENOMEM;
@@ -605,7 +457,7 @@ static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) 
{

	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

	unsigned long ip = regs->psw.addr & PSW_ADDR_INSN;

	int fixup = get_fixup_type(p->ainsn.insn);

	int fixup = probe_get_fixup_type(p->ainsn.insn);



	if (fixup & FIXUP_PSW_NORMAL)

		ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn;

arch/s390/lib/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -6,3 +6,5 @@ lib-y += delay.o string.o uaccess.o find.o 
obj-$(CONFIG_32BIT) += div64.o qrnnd.o ucmpdi2.o mem32.o

obj-$(CONFIG_64BIT) += mem64.o

lib-$(CONFIG_SMP) += spinlock.o

lib-$(CONFIG_KPROBES) += probes.o

lib-$(CONFIG_UPROBES) += probes.o

arch/s390/lib/probes.c

0 → 100644
+159 −0
Original line number Diff line number Diff line 
/*

 *    Common helper functions for kprobes and uprobes

 *

 *    Copyright IBM Corp. 2014

 */



#include <linux/kprobes.h>

#include <asm/dis.h>



int probe_is_prohibited_opcode(u16 *insn)

{

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

		return -EINVAL;

	switch (insn[0] >> 8) {

	case 0x0c:	/* bassm */

	case 0x0b:	/* bsm	 */

	case 0x83:	/* diag  */

	case 0x44:	/* ex	 */

	case 0xac:	/* stnsm */

	case 0xad:	/* stosm */

		return -EINVAL;

	case 0xc6:

		switch (insn[0] & 0x0f) {

		case 0x00: /* exrl   */

			return -EINVAL;

		}

	}

	switch (insn[0]) {

	case 0x0101:	/* pr	 */

	case 0xb25a:	/* bsa	 */

	case 0xb240:	/* bakr  */

	case 0xb258:	/* bsg	 */

	case 0xb218:	/* pc	 */

	case 0xb228:	/* pt	 */

	case 0xb98d:	/* epsw	 */

	case 0xe560:	/* tbegin */

	case 0xe561:	/* tbeginc */

	case 0xb2f8:	/* tend	 */

		return -EINVAL;

	}

	return 0;

}



int probe_get_fixup_type(u16 *insn)

{

	/* default fixup method */

	int fixup = FIXUP_PSW_NORMAL;



	switch (insn[0] >> 8) {

	case 0x05:	/* balr	*/

	case 0x0d:	/* basr */

		fixup = FIXUP_RETURN_REGISTER;

		/* if r2 = 0, no branch will be taken */

		if ((insn[0] & 0x0f) == 0)

			fixup |= FIXUP_BRANCH_NOT_TAKEN;

		break;

	case 0x06:	/* bctr	*/

	case 0x07:	/* bcr	*/

		fixup = FIXUP_BRANCH_NOT_TAKEN;

		break;

	case 0x45:	/* bal	*/

	case 0x4d:	/* bas	*/

		fixup = FIXUP_RETURN_REGISTER;

		break;

	case 0x47:	/* bc	*/

	case 0x46:	/* bct	*/

	case 0x86:	/* bxh	*/

	case 0x87:	/* bxle	*/

		fixup = FIXUP_BRANCH_NOT_TAKEN;

		break;

	case 0x82:	/* lpsw	*/

		fixup = FIXUP_NOT_REQUIRED;

		break;

	case 0xb2:	/* lpswe */

		if ((insn[0] & 0xff) == 0xb2)

			fixup = FIXUP_NOT_REQUIRED;

		break;

	case 0xa7:	/* bras	*/

		if ((insn[0] & 0x0f) == 0x05)

			fixup |= FIXUP_RETURN_REGISTER;

		break;

	case 0xc0:

		if ((insn[0] & 0x0f) == 0x05)	/* brasl */

			fixup |= FIXUP_RETURN_REGISTER;

		break;

	case 0xeb:

		switch (insn[2] & 0xff) {

		case 0x44: /* bxhg  */

		case 0x45: /* bxleg */

			fixup = FIXUP_BRANCH_NOT_TAKEN;

			break;

		}

		break;

	case 0xe3:	/* bctg	*/

		if ((insn[2] & 0xff) == 0x46)

			fixup = FIXUP_BRANCH_NOT_TAKEN;

		break;

	case 0xec:

		switch (insn[2] & 0xff) {

		case 0xe5: /* clgrb */

		case 0xe6: /* cgrb  */

		case 0xf6: /* crb   */

		case 0xf7: /* clrb  */

		case 0xfc: /* cgib  */

		case 0xfd: /* cglib */

		case 0xfe: /* cib   */

		case 0xff: /* clib  */

			fixup = FIXUP_BRANCH_NOT_TAKEN;

			break;

		}

		break;

	}

	return fixup;

}



int probe_is_insn_relative_long(u16 *insn)

{

	/* Check if we have a RIL-b or RIL-c format instruction which

	 * we need to modify in order to avoid instruction emulation. */

	switch (insn[0] >> 8) {

	case 0xc0:

		if ((insn[0] & 0x0f) == 0x00) /* larl */

			return true;

		break;

	case 0xc4:

		switch (insn[0] & 0x0f) {

		case 0x02: /* llhrl  */

		case 0x04: /* lghrl  */

		case 0x05: /* lhrl   */

		case 0x06: /* llghrl */

		case 0x07: /* sthrl  */

		case 0x08: /* lgrl   */

		case 0x0b: /* stgrl  */

		case 0x0c: /* lgfrl  */

		case 0x0d: /* lrl    */

		case 0x0e: /* llgfrl */

		case 0x0f: /* strl   */

			return true;

		}

		break;

	case 0xc6:

		switch (insn[0] & 0x0f) {

		case 0x02: /* pfdrl  */

		case 0x04: /* cghrl  */

		case 0x05: /* chrl   */

		case 0x06: /* clghrl */

		case 0x07: /* clhrl  */

		case 0x08: /* cgrl   */

		case 0x0a: /* clgrl  */

		case 0x0c: /* cgfrl  */

		case 0x0d: /* crl    */

		case 0x0e: /* clgfrl */

		case 0x0f: /* clrl   */

			return true;

		}

		break;

	}

	return false;

}