* <anil.s.keshavamurthy@intel.com> adapted from i386
*/
-#include <linux/config.h>
#include <linux/kprobes.h>
#include <linux/ptrace.h>
-#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/preempt.h>
#include <asm/pgtable.h>
#include <asm/kdebug.h>
#include <asm/sections.h>
+#include <asm/uaccess.h>
extern void jprobe_inst_return(void);
-/* kprobe_status settings */
-#define KPROBE_HIT_ACTIVE 0x00000001
-#define KPROBE_HIT_SS 0x00000002
-
-static struct kprobe *current_kprobe, *kprobe_prev;
-static unsigned long kprobe_status, kprobe_status_prev;
-static struct pt_regs jprobe_saved_regs;
+DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
+DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
enum instruction_type {A, I, M, F, B, L, X, u};
static enum instruction_type bundle_encoding[32][3] = {
update_kprobe_inst_flag(template, slot, major_opcode, kprobe_inst, p);
}
-static inline void get_kprobe_inst(bundle_t *bundle, uint slot,
+static void __kprobes get_kprobe_inst(bundle_t *bundle, uint slot,
unsigned long *kprobe_inst, uint *major_opcode)
{
unsigned long kprobe_inst_p0, kprobe_inst_p1;
}
/* Returns non-zero if the addr is in the Interrupt Vector Table */
-static inline int in_ivt_functions(unsigned long addr)
+static int __kprobes in_ivt_functions(unsigned long addr)
{
return (addr >= (unsigned long)__start_ivt_text
&& addr < (unsigned long)__end_ivt_text);
return 0;
}
-static inline void save_previous_kprobe(void)
+static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
{
- kprobe_prev = current_kprobe;
- kprobe_status_prev = kprobe_status;
+ kcb->prev_kprobe.kp = kprobe_running();
+ kcb->prev_kprobe.status = kcb->kprobe_status;
}
-static inline void restore_previous_kprobe(void)
+static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
{
- current_kprobe = kprobe_prev;
- kprobe_status = kprobe_status_prev;
+ __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+ kcb->kprobe_status = kcb->prev_kprobe.status;
}
-static inline void set_current_kprobe(struct kprobe *p)
+static void __kprobes set_current_kprobe(struct kprobe *p,
+ struct kprobe_ctlblk *kcb)
{
- current_kprobe = p;
+ __get_cpu_var(current_kprobe) = p;
}
static void kretprobe_trampoline(void)
struct kretprobe_instance *ri = NULL;
struct hlist_head *head;
struct hlist_node *node, *tmp;
- unsigned long orig_ret_address = 0;
+ unsigned long flags, orig_ret_address = 0;
unsigned long trampoline_address =
((struct fnptr *)kretprobe_trampoline)->ip;
- head = kretprobe_inst_table_head(current);
+ spin_lock_irqsave(&kretprobe_lock, flags);
+ head = kretprobe_inst_table_head(current);
/*
* It is possible to have multiple instances associated with a given
* kretprobe_trampoline
*/
hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
- if (ri->task != current)
+ if (ri->task != current)
/* another task is sharing our hash bucket */
- continue;
+ continue;
if (ri->rp && ri->rp->handler)
ri->rp->handler(ri, regs);
BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address));
regs->cr_iip = orig_ret_address;
- unlock_kprobes();
+ reset_current_kprobe();
+ spin_unlock_irqrestore(&kretprobe_lock, flags);
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;
+ /*
+ * By returning a non-zero value, we are telling
+ * kprobe_handler() that we don't want the post_handler
+ * to run (and have re-enabled preemption)
+ */
+ return 1;
}
+/* Called with kretprobe_lock held */
void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
struct pt_regs *regs)
{
return 0;
}
+void __kprobes flush_insn_slot(struct kprobe *p)
+{
+ unsigned long arm_addr;
+
+ arm_addr = ((unsigned long)&p->opcode.bundle) & ~0xFULL;
+ flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
+}
+
void __kprobes arch_arm_kprobe(struct kprobe *p)
{
unsigned long addr = (unsigned long)p->addr;
unsigned long arm_addr = addr & ~0xFULL;
+ flush_insn_slot(p);
memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t));
flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
}
flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
}
-void __kprobes arch_remove_kprobe(struct kprobe *p)
-{
-}
-
/*
* We are resuming execution after a single step fault, so the pt_regs
* structure reflects the register state after we executed the instruction
int ret = 0;
struct pt_regs *regs = args->regs;
kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs);
+ struct kprobe_ctlblk *kcb;
+
+ /*
+ * We don't want to be preempted for the entire
+ * duration of kprobe processing
+ */
+ preempt_disable();
+ kcb = get_kprobe_ctlblk();
/* Handle recursion cases */
if (kprobe_running()) {
p = get_kprobe(addr);
if (p) {
- if ( (kprobe_status == KPROBE_HIT_SS) &&
+ if ((kcb->kprobe_status == KPROBE_HIT_SS) &&
(p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) {
ia64_psr(regs)->ss = 0;
- unlock_kprobes();
goto no_kprobe;
}
/* We have reentered the pre_kprobe_handler(), since
* just single step on the instruction of the new probe
* without calling any user handlers.
*/
- save_previous_kprobe();
- set_current_kprobe(p);
- p->nmissed++;
+ save_previous_kprobe(kcb);
+ set_current_kprobe(p, kcb);
+ kprobes_inc_nmissed_count(p);
prepare_ss(p, regs);
- kprobe_status = KPROBE_REENTER;
+ kcb->kprobe_status = KPROBE_REENTER;
return 1;
} else if (args->err == __IA64_BREAK_JPROBE) {
/*
* jprobe instrumented function just completed
*/
- p = current_kprobe;
+ p = __get_cpu_var(current_kprobe);
if (p->break_handler && p->break_handler(p, regs)) {
goto ss_probe;
}
+ } else if (!is_ia64_break_inst(regs)) {
+ /* The breakpoint instruction was removed by
+ * another cpu right after we hit, no further
+ * handling of this interrupt is appropriate
+ */
+ ret = 1;
+ goto no_kprobe;
} else {
/* Not our break */
goto no_kprobe;
}
}
- lock_kprobes();
p = get_kprobe(addr);
if (!p) {
- unlock_kprobes();
if (!is_ia64_break_inst(regs)) {
/*
* The breakpoint instruction was removed right
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);
+ set_current_kprobe(p, kcb);
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
if (p->pre_handler && p->pre_handler(p, regs))
/*
ss_probe:
prepare_ss(p, regs);
- kprobe_status = KPROBE_HIT_SS;
+ kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
no_kprobe:
+ preempt_enable_no_resched();
return ret;
}
static int __kprobes post_kprobes_handler(struct pt_regs *regs)
{
- if (!kprobe_running())
+ struct kprobe *cur = kprobe_running();
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+ if (!cur)
return 0;
- if ((kprobe_status != KPROBE_REENTER) && current_kprobe->post_handler) {
- kprobe_status = KPROBE_HIT_SSDONE;
- current_kprobe->post_handler(current_kprobe, regs, 0);
+ if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ cur->post_handler(cur, regs, 0);
}
- resume_execution(current_kprobe, regs);
+ resume_execution(cur, regs);
/*Restore back the original saved kprobes variables and continue. */
- if (kprobe_status == KPROBE_REENTER) {
- restore_previous_kprobe();
+ if (kcb->kprobe_status == KPROBE_REENTER) {
+ restore_previous_kprobe(kcb);
goto out;
}
-
- unlock_kprobes();
+ reset_current_kprobe();
out:
preempt_enable_no_resched();
static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
{
- if (!kprobe_running())
- return 0;
+ struct kprobe *cur = kprobe_running();
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- if (current_kprobe->fault_handler &&
- current_kprobe->fault_handler(current_kprobe, regs, trapnr))
- return 1;
- if (kprobe_status & KPROBE_HIT_SS) {
- resume_execution(current_kprobe, regs);
- unlock_kprobes();
+ switch(kcb->kprobe_status) {
+ case KPROBE_HIT_SS:
+ case KPROBE_REENTER:
+ /*
+ * We are here because the instruction being single
+ * stepped caused a page fault. We reset the current
+ * kprobe and the instruction pointer points back to
+ * the probe address and allow the page fault handler
+ * to continue as a normal page fault.
+ */
+ regs->cr_iip = ((unsigned long)cur->addr) & ~0xFULL;
+ ia64_psr(regs)->ri = ((unsigned long)cur->addr) & 0xf;
+ if (kcb->kprobe_status == KPROBE_REENTER)
+ restore_previous_kprobe(kcb);
+ else
+ reset_current_kprobe();
preempt_enable_no_resched();
+ break;
+ case KPROBE_HIT_ACTIVE:
+ case KPROBE_HIT_SSDONE:
+ /*
+ * We increment the nmissed count for accounting,
+ * we can also use npre/npostfault count for accouting
+ * these specific fault cases.
+ */
+ kprobes_inc_nmissed_count(cur);
+
+ /*
+ * We come here because instructions in the pre/post
+ * handler caused the page_fault, this could happen
+ * if handler tries to access user space by
+ * copy_from_user(), get_user() etc. Let the
+ * user-specified handler try to fix it first.
+ */
+ if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
+ return 1;
+
+ /*
+ * Let ia64_do_page_fault() fix it.
+ */
+ break;
+ default:
+ break;
}
return 0;
struct die_args *args = (struct die_args *)data;
int ret = NOTIFY_DONE;
- preempt_disable();
+ if (args->regs && user_mode(args->regs))
+ return ret;
+
switch(val) {
case DIE_BREAK:
- if (pre_kprobes_handler(args))
- ret = NOTIFY_STOP;
+ /* err is break number from ia64_bad_break() */
+ if (args->err == 0x80200 || args->err == 0x80300 || args->err == 0)
+ if (pre_kprobes_handler(args))
+ ret = NOTIFY_STOP;
break;
- case DIE_SS:
- if (post_kprobes_handler(args->regs))
- ret = NOTIFY_STOP;
+ case DIE_FAULT:
+ /* err is vector number from ia64_fault() */
+ if (args->err == 36)
+ if (post_kprobes_handler(args->regs))
+ ret = NOTIFY_STOP;
break;
case DIE_PAGE_FAULT:
- if (kprobes_fault_handler(args->regs, args->trapnr))
+ /* kprobe_running() needs smp_processor_id() */
+ preempt_disable();
+ if (kprobe_running() &&
+ kprobes_fault_handler(args->regs, args->trapnr))
ret = NOTIFY_STOP;
+ preempt_enable();
default:
break;
}
- preempt_enable();
return ret;
}
+struct param_bsp_cfm {
+ unsigned long ip;
+ unsigned long *bsp;
+ unsigned long cfm;
+};
+
+static void ia64_get_bsp_cfm(struct unw_frame_info *info, void *arg)
+{
+ unsigned long ip;
+ struct param_bsp_cfm *lp = arg;
+
+ do {
+ unw_get_ip(info, &ip);
+ if (ip == 0)
+ break;
+ if (ip == lp->ip) {
+ unw_get_bsp(info, (unsigned long*)&lp->bsp);
+ unw_get_cfm(info, (unsigned long*)&lp->cfm);
+ return;
+ }
+ } while (unw_unwind(info) >= 0);
+ lp->bsp = 0;
+ lp->cfm = 0;
+ return;
+}
+
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;
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ struct param_bsp_cfm pa;
+ int bytes;
+
+ /*
+ * Callee owns the argument space and could overwrite it, eg
+ * tail call optimization. So to be absolutely safe
+ * we save the argument space before transfering the control
+ * to instrumented jprobe function which runs in
+ * the process context
+ */
+ pa.ip = regs->cr_iip;
+ unw_init_running(ia64_get_bsp_cfm, &pa);
+ bytes = (char *)ia64_rse_skip_regs(pa.bsp, pa.cfm & 0x3f)
+ - (char *)pa.bsp;
+ memcpy( kcb->jprobes_saved_stacked_regs,
+ pa.bsp,
+ bytes );
+ kcb->bsp = pa.bsp;
+ kcb->cfm = pa.cfm;
/* save architectural state */
- jprobe_saved_regs = *regs;
+ kcb->jprobe_saved_regs = *regs;
/* after rfi, execute the jprobe instrumented function */
regs->cr_iip = addr & ~0xFULL;
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
- *regs = jprobe_saved_regs;
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ int bytes;
+
+ /* restoring architectural state */
+ *regs = kcb->jprobe_saved_regs;
+
+ /* restoring the original argument space */
+ flush_register_stack();
+ bytes = (char *)ia64_rse_skip_regs(kcb->bsp, kcb->cfm & 0x3f)
+ - (char *)kcb->bsp;
+ memcpy( kcb->bsp,
+ kcb->jprobes_saved_stacked_regs,
+ bytes );
+ invalidate_stacked_regs();
+
+ preempt_enable_no_resched();
return 1;
}