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authorJan Willeke <willeke@de.ibm.com>2014-09-22 16:37:27 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2014-09-25 10:52:14 +0200
commit975fab17399a2b29985166181ad80e5f50fa42e9 (patch)
tree385dac7c1384947e5b3a520d40b60cb77d5797b1 /arch/s390/lib
parentbbae71bf9c2fe90dc5642d4cddbbc1994861fd92 (diff)
downloadlinux-linaro-stable-975fab17399a2b29985166181ad80e5f50fa42e9.tar.gz
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: 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>
Diffstat (limited to 'arch/s390/lib')
-rw-r--r--arch/s390/lib/Makefile2
-rw-r--r--arch/s390/lib/probes.c159
2 files changed, 161 insertions, 0 deletions
diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
index c6d752e8bf28..a01df233856f 100644
--- a/arch/s390/lib/Makefile
+++ b/arch/s390/lib/Makefile
@@ -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
diff --git a/arch/s390/lib/probes.c b/arch/s390/lib/probes.c
new file mode 100644
index 000000000000..c5d64a099719
--- /dev/null
+++ b/arch/s390/lib/probes.c
@@ -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;
+}