#include <linux/stop_machine.h>
#include <linux/kdebug.h>
#include <linux/uaccess.h>
-#include <asm/cacheflush.h>
-#include <asm/sections.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/hardirq.h>
+#include <asm/cacheflush.h>
+#include <asm/sections.h>
+#include <asm/dis.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe);
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
struct kretprobe_blackpoint kretprobe_blacklist[] = { };
+DEFINE_INSN_CACHE_OPS(dmainsn);
+
+static void *alloc_dmainsn_page(void)
+{
+ return (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
+}
+
+static void free_dmainsn_page(void *page)
+{
+ free_page((unsigned long)page);
+}
+
+struct kprobe_insn_cache kprobe_dmainsn_slots = {
+ .mutex = __MUTEX_INITIALIZER(kprobe_dmainsn_slots.mutex),
+ .alloc = alloc_dmainsn_page,
+ .free = free_dmainsn_page,
+ .pages = LIST_HEAD_INIT(kprobe_dmainsn_slots.pages),
+ .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 0xac: /* stnsm */
case 0xad: /* stosm */
return -EINVAL;
+ case 0xc6:
+ switch (insn[0] & 0x0f) {
+ case 0x00: /* exrl */
+ return -EINVAL;
+ }
}
switch (insn[0]) {
case 0x0101: /* pr */
fixup |= FIXUP_RETURN_REGISTER;
break;
case 0xc0:
- if ((insn[0] & 0x0f) == 0x00 || /* larl */
- (insn[0] & 0x0f) == 0x05) /* brasl */
- fixup |= FIXUP_RETURN_REGISTER;
+ if ((insn[0] & 0x0f) == 0x05) /* brasl */
+ fixup |= FIXUP_RETURN_REGISTER;
break;
case 0xeb:
switch (insn[2] & 0xff) {
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))
+ return;
+ /*
+ * For pc-relative instructions in RIL-b or RIL-c format patch the
+ * RI2 displacement field. We have already made sure that the insn
+ * slot for the patched instruction is within the same 2GB area
+ * as the original instruction (either kernel image or module area).
+ * Therefore the new displacement will always fit.
+ */
+ disp = *(s32 *)&p->ainsn.insn[1];
+ addr = (u64)(unsigned long)p->addr;
+ new_addr = (u64)(unsigned long)p->ainsn.insn;
+ new_disp = ((addr + (disp * 2)) - new_addr) / 2;
+ *(s32 *)&p->ainsn.insn[1] = new_disp;
+}
+
+static inline int is_kernel_addr(void *addr)
+{
+ return addr < (void *)_end;
+}
+
+static inline int is_module_addr(void *addr)
+{
+#ifdef CONFIG_64BIT
+ BUILD_BUG_ON(MODULES_LEN > (1UL << 31));
+ if (addr < (void *)MODULES_VADDR)
+ return 0;
+ if (addr > (void *)MODULES_END)
+ return 0;
+#endif
+ return 1;
+}
+
+static int __kprobes s390_get_insn_slot(struct kprobe *p)
+{
+ /*
+ * Get an insn slot that is within the same 2GB area like the original
+ * instruction. That way instructions with a 32bit signed displacement
+ * field can be patched and executed within the insn slot.
+ */
+ p->ainsn.insn = NULL;
+ if (is_kernel_addr(p->addr))
+ p->ainsn.insn = get_dmainsn_slot();
+ else if (is_module_addr(p->addr))
+ p->ainsn.insn = get_insn_slot();
+ return p->ainsn.insn ? 0 : -ENOMEM;
+}
+
+static void __kprobes s390_free_insn_slot(struct kprobe *p)
+{
+ if (!p->ainsn.insn)
+ return;
+ if (is_kernel_addr(p->addr))
+ free_dmainsn_slot(p->ainsn.insn, 0);
+ else
+ free_insn_slot(p->ainsn.insn, 0);
+ p->ainsn.insn = NULL;
+}
+
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))
return -EINVAL;
-
+ if (s390_get_insn_slot(p))
+ return -ENOMEM;
p->opcode = *p->addr;
- memcpy(p->ainsn.insn, p->addr, ((p->opcode >> 14) + 3) & -2);
-
+ copy_instruction(p);
return 0;
}
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
+ s390_free_insn_slot(p);
}
static void __kprobes enable_singlestep(struct kprobe_ctlblk *kcb,
ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn;
if (fixup & FIXUP_BRANCH_NOT_TAKEN) {
- int ilen = ((p->ainsn.insn[0] >> 14) + 3) & -2;
+ int ilen = insn_length(p->ainsn.insn[0] >> 8);
if (ip - (unsigned long) p->ainsn.insn == ilen)
ip = (unsigned long) p->addr + ilen;
}
projects / karo-tx-linux.git / blobdiff