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s390/uprobes: common library for kprobes and uprobes

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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: Jan Willeke <willeke@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Jan Willeke 2014-09-22 16:37:27 +02:00 committed by Martin Schwidefsky
parent bbae71bf9c
commit 975fab1739
4 changed files with 168 additions and 151 deletions
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4
arch/s390/include/asm/kprobes.h
View file

@ -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 */

154
arch/s390/kernel/kprobes.c
View file

@ -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;

2
arch/s390/lib/Makefile
View file

@ -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

159
arch/s390/lib/probes.c Normal file
View file

@ -0,0 +1,159 @@
/*
* 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;
}