#include <asm/pgtable.h>
#include <asm/kdebug.h>
+#include <asm/sections.h>
extern void jprobe_inst_return(void);
* is IP relative instruction and update the kprobe
* inst flag accordingly
*/
-static void update_kprobe_inst_flag(uint template, uint slot, uint major_opcode,
- unsigned long kprobe_inst, struct kprobe *p)
+static void __kprobes update_kprobe_inst_flag(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst,
+ struct kprobe *p)
{
p->ainsn.inst_flag = 0;
p->ainsn.target_br_reg = 0;
+ /* Check for Break instruction
+ * Bits 37:40 Major opcode to be zero
+ * Bits 27:32 X6 to be zero
+ * Bits 32:35 X3 to be zero
+ */
+ if ((!major_opcode) && (!((kprobe_inst >> 27) & 0x1FF)) ) {
+ /* is a break instruction */
+ p->ainsn.inst_flag |= INST_FLAG_BREAK_INST;
+ return;
+ }
+
if (bundle_encoding[template][slot] == B) {
switch (major_opcode) {
case INDIRECT_CALL_OPCODE:
* Returns 0 if supported
* Returns -EINVAL if unsupported
*/
-static int unsupported_inst(uint template, uint slot, uint major_opcode,
- unsigned long kprobe_inst, struct kprobe *p)
+static int __kprobes unsupported_inst(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst,
+ struct kprobe *p)
{
unsigned long addr = (unsigned long)p->addr;
* on which we are inserting kprobe is cmp instruction
* with ctype as unc.
*/
-static uint is_cmp_ctype_unc_inst(uint template, uint slot, uint major_opcode,
-unsigned long kprobe_inst)
+static uint __kprobes is_cmp_ctype_unc_inst(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst)
{
cmp_inst_t cmp_inst;
uint ctype_unc = 0;
* In this function we override the bundle with
* the break instruction at the given slot.
*/
-static void prepare_break_inst(uint template, uint slot, uint major_opcode,
- unsigned long kprobe_inst, struct kprobe *p)
+static void __kprobes prepare_break_inst(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst,
+ struct kprobe *p)
{
unsigned long break_inst = BREAK_INST;
bundle_t *bundle = &p->ainsn.insn.bundle;
}
}
-static int valid_kprobe_addr(int template, int slot, unsigned long addr)
+/* Returns non-zero if the addr is in the Interrupt Vector Table */
+static inline int in_ivt_functions(unsigned long addr)
+{
+ return (addr >= (unsigned long)__start_ivt_text
+ && addr < (unsigned long)__end_ivt_text);
+}
+
+static int __kprobes valid_kprobe_addr(int template, int slot,
+ unsigned long addr)
{
if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) {
- printk(KERN_WARNING "Attempting to insert unaligned kprobe at 0x%lx\n",
- addr);
+ printk(KERN_WARNING "Attempting to insert unaligned kprobe "
+ "at 0x%lx\n", addr);
+ return -EINVAL;
+ }
+
+ if (in_ivt_functions(addr)) {
+ printk(KERN_WARNING "Kprobes can't be inserted inside "
+ "IVT functions at 0x%lx\n", addr);
+ return -EINVAL;
+ }
+
+ if (slot == 1 && bundle_encoding[template][1] != L) {
+ printk(KERN_WARNING "Inserting kprobes on slot #1 "
+ "is not supported\n");
return -EINVAL;
}
+
return 0;
}
current_kprobe = p;
}
-int arch_prepare_kprobe(struct kprobe *p)
+static void kretprobe_trampoline(void)
+{
+}
+
+/*
+ * At this point the target function has been tricked into
+ * returning into our trampoline. Lookup the associated instance
+ * and then:
+ * - call the handler function
+ * - cleanup by marking the instance as unused
+ * - long jump back to the original return address
+ */
+int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct kretprobe_instance *ri = NULL;
+ struct hlist_head *head;
+ struct hlist_node *node, *tmp;
+ unsigned long orig_ret_address = 0;
+ unsigned long trampoline_address =
+ ((struct fnptr *)kretprobe_trampoline)->ip;
+
+ head = kretprobe_inst_table_head(current);
+
+ /*
+ * It is possible to have multiple instances associated with a given
+ * task either because an multiple functions in the call path
+ * have a return probe installed on them, and/or more then one return
+ * return probe was registered for a target function.
+ *
+ * We can handle this because:
+ * - instances are always inserted at the head of the list
+ * - when multiple return probes are registered for the same
+ * function, the first instance's ret_addr will point to the
+ * real return address, and all the rest will point to
+ * kretprobe_trampoline
+ */
+ hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+ if (ri->task != current)
+ /* another task is sharing our hash bucket */
+ continue;
+
+ if (ri->rp && ri->rp->handler)
+ ri->rp->handler(ri, regs);
+
+ orig_ret_address = (unsigned long)ri->ret_addr;
+ recycle_rp_inst(ri);
+
+ if (orig_ret_address != trampoline_address)
+ /*
+ * This is the real return address. Any other
+ * instances associated with this task are for
+ * other calls deeper on the call stack
+ */
+ break;
+ }
+
+ BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address));
+ regs->cr_iip = orig_ret_address;
+
+ unlock_kprobes();
+ preempt_enable_no_resched();
+
+ /*
+ * By returning a non-zero value, we are telling
+ * kprobe_handler() that we have handled unlocking
+ * and re-enabling preemption
+ */
+ return 1;
+}
+
+void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
+ struct pt_regs *regs)
+{
+ struct kretprobe_instance *ri;
+
+ if ((ri = get_free_rp_inst(rp)) != NULL) {
+ ri->rp = rp;
+ ri->task = current;
+ ri->ret_addr = (kprobe_opcode_t *)regs->b0;
+
+ /* Replace the return addr with trampoline addr */
+ regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
+
+ add_rp_inst(ri);
+ } else {
+ rp->nmissed++;
+ }
+}
+
+int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
unsigned long addr = (unsigned long) p->addr;
unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL);
return 0;
}
-void arch_arm_kprobe(struct kprobe *p)
+void __kprobes arch_arm_kprobe(struct kprobe *p)
{
unsigned long addr = (unsigned long)p->addr;
unsigned long arm_addr = addr & ~0xFULL;
flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
}
-void arch_disarm_kprobe(struct kprobe *p)
+void __kprobes arch_disarm_kprobe(struct kprobe *p)
{
unsigned long addr = (unsigned long)p->addr;
unsigned long arm_addr = addr & ~0xFULL;
flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
}
-void arch_remove_kprobe(struct kprobe *p)
+void __kprobes arch_remove_kprobe(struct kprobe *p)
{
}
* to original stack address, handle the case where we need to fixup the
* relative IP address and/or fixup branch register.
*/
-static void resume_execution(struct kprobe *p, struct pt_regs *regs)
+static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
{
unsigned long bundle_addr = ((unsigned long) (&p->opcode.bundle)) & ~0xFULL;
unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL;
ia64_psr(regs)->ss = 0;
}
-static void prepare_ss(struct kprobe *p, struct pt_regs *regs)
+static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs)
{
unsigned long bundle_addr = (unsigned long) &p->opcode.bundle;
unsigned long slot = (unsigned long)p->addr & 0xf;
- /* Update instruction pointer (IIP) and slot number (IPSR.ri) */
- regs->cr_iip = bundle_addr & ~0xFULL;
+ /* single step inline if break instruction */
+ if (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)
+ regs->cr_iip = (unsigned long)p->addr & ~0xFULL;
+ else
+ regs->cr_iip = bundle_addr & ~0xFULL;
if (slot > 2)
slot = 0;
ia64_psr(regs)->ss = 1;
}
-static int pre_kprobes_handler(struct die_args *args)
+static int __kprobes is_ia64_break_inst(struct pt_regs *regs)
+{
+ unsigned int slot = ia64_psr(regs)->ri;
+ unsigned int template, major_opcode;
+ unsigned long kprobe_inst;
+ unsigned long *kprobe_addr = (unsigned long *)regs->cr_iip;
+ bundle_t bundle;
+
+ memcpy(&bundle, kprobe_addr, sizeof(bundle_t));
+ template = bundle.quad0.template;
+
+ /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
+ if (slot == 1 && bundle_encoding[template][1] == L)
+ slot++;
+
+ /* Get Kprobe probe instruction at given slot*/
+ get_kprobe_inst(&bundle, slot, &kprobe_inst, &major_opcode);
+
+ /* For break instruction,
+ * Bits 37:40 Major opcode to be zero
+ * Bits 27:32 X6 to be zero
+ * Bits 32:35 X3 to be zero
+ */
+ if (major_opcode || ((kprobe_inst >> 27) & 0x1FF) ) {
+ /* Not a break instruction */
+ return 0;
+ }
+
+ /* Is a break instruction */
+ return 1;
+}
+
+static int __kprobes pre_kprobes_handler(struct die_args *args)
{
struct kprobe *p;
int ret = 0;
struct pt_regs *regs = args->regs;
kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs);
- preempt_disable();
-
/* Handle recursion cases */
if (kprobe_running()) {
p = get_kprobe(addr);
if (p) {
- if (kprobe_status == KPROBE_HIT_SS) {
+ if ( (kprobe_status == KPROBE_HIT_SS) &&
+ (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) {
+ ia64_psr(regs)->ss = 0;
unlock_kprobes();
goto no_kprobe;
}
p = get_kprobe(addr);
if (!p) {
unlock_kprobes();
+ if (!is_ia64_break_inst(regs)) {
+ /*
+ * The breakpoint instruction was removed right
+ * after we hit it. Another cpu has removed
+ * either a probepoint or a debugger breakpoint
+ * at this address. In either case, no further
+ * handling of this interrupt is appropriate.
+ */
+ ret = 1;
+
+ }
+
+ /* Not one of our break, let kernel handle it */
goto no_kprobe;
}
+ /*
+ * This preempt_disable() matches the preempt_enable_no_resched()
+ * in post_kprobes_handler()
+ */
+ preempt_disable();
kprobe_status = KPROBE_HIT_ACTIVE;
set_current_kprobe(p);
if (p->pre_handler && p->pre_handler(p, regs))
/*
* Our pre-handler is specifically requesting that we just
- * do a return. This is handling the case where the
- * pre-handler is really our special jprobe pre-handler.
+ * do a return. This is used for both the jprobe pre-handler
+ * and the kretprobe trampoline
*/
return 1;
return 1;
no_kprobe:
- preempt_enable_no_resched();
return ret;
}
-static int post_kprobes_handler(struct pt_regs *regs)
+static int __kprobes post_kprobes_handler(struct pt_regs *regs)
{
if (!kprobe_running())
return 0;
return 1;
}
-static int kprobes_fault_handler(struct pt_regs *regs, int trapnr)
+static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
{
if (!kprobe_running())
return 0;
return 0;
}
-int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,
- void *data)
+int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
+ unsigned long val, void *data)
{
struct die_args *args = (struct die_args *)data;
+ int ret = NOTIFY_DONE;
+
+ preempt_disable();
switch(val) {
case DIE_BREAK:
if (pre_kprobes_handler(args))
- return NOTIFY_STOP;
+ ret = NOTIFY_STOP;
break;
case DIE_SS:
if (post_kprobes_handler(args->regs))
- return NOTIFY_STOP;
+ ret = NOTIFY_STOP;
break;
case DIE_PAGE_FAULT:
if (kprobes_fault_handler(args->regs, args->trapnr))
- return NOTIFY_STOP;
+ ret = NOTIFY_STOP;
default:
break;
}
- return NOTIFY_DONE;
+ preempt_enable();
+ return ret;
}
-int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
+int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
struct jprobe *jp = container_of(p, struct jprobe, kp);
unsigned long addr = ((struct fnptr *)(jp->entry))->ip;
return 1;
}
-int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
+int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
*regs = jprobe_saved_regs;
return 1;
}
+
+static struct kprobe trampoline_p = {
+ .pre_handler = trampoline_probe_handler
+};
+
+int __init arch_init_kprobes(void)
+{
+ trampoline_p.addr =
+ (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip;
+ return register_kprobe(&trampoline_p);
+}
projects / platform / kernel / linux-arm64.git / blobdiff