* <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>
-/* kprobe_status settings */
-#define KPROBE_HIT_ACTIVE 0x00000001
-#define KPROBE_HIT_SS 0x00000002
+extern void jprobe_inst_return(void);
-static struct kprobe *current_kprobe;
-static unsigned long kprobe_status;
+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] = {
{ u, u, u }, /* 1F */
};
-int arch_prepare_kprobe(struct kprobe *p)
+/*
+ * In this function we check to see if the instruction
+ * is IP relative instruction and update the kprobe
+ * inst flag accordingly
+ */
+static void __kprobes update_kprobe_inst_flag(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst,
+ struct kprobe *p)
{
- unsigned long addr = (unsigned long) p->addr;
- unsigned long bundle_addr = addr & ~0xFULL;
- unsigned long slot = addr & 0xf;
- bundle_t bundle;
- unsigned long template;
+ p->ainsn.inst_flag = 0;
+ p->ainsn.target_br_reg = 0;
- /*
- * TODO: Verify that a probe is not being inserted
- * in sensitive regions of code
- * TODO: Verify that the memory holding the probe is rwx
- * TODO: verify this is a kernel address
+ /* 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
*/
- memcpy(&bundle, (unsigned long *)bundle_addr, sizeof(bundle_t));
- template = bundle.quad0.template;
- if (((bundle_encoding[template][1] == L) && slot > 1) || (slot > 2)) {
- printk(KERN_WARNING "Attempting to insert unaligned kprobe at 0x%lx\n", addr);
- return -EINVAL;
+ if ((!major_opcode) && (!((kprobe_inst >> 27) & 0x1FF)) ) {
+ /* is a break instruction */
+ p->ainsn.inst_flag |= INST_FLAG_BREAK_INST;
+ return;
}
- return 0;
+
+ if (bundle_encoding[template][slot] == B) {
+ switch (major_opcode) {
+ case INDIRECT_CALL_OPCODE:
+ p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
+ p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
+ break;
+ case IP_RELATIVE_PREDICT_OPCODE:
+ case IP_RELATIVE_BRANCH_OPCODE:
+ p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
+ break;
+ case IP_RELATIVE_CALL_OPCODE:
+ p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
+ p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
+ p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
+ break;
+ }
+ } else if (bundle_encoding[template][slot] == X) {
+ switch (major_opcode) {
+ case LONG_CALL_OPCODE:
+ p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
+ p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
+ break;
+ }
+ }
+ return;
}
-void arch_copy_kprobe(struct kprobe *p)
+/*
+ * In this function we check to see if the instruction
+ * on which we are inserting kprobe is supported.
+ * Returns 0 if supported
+ * Returns -EINVAL if unsupported
+ */
+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;
- unsigned long bundle_addr = addr & ~0xFULL;
- memcpy(&p->ainsn.insn.bundle, (unsigned long *)bundle_addr,
- sizeof(bundle_t));
- memcpy(&p->opcode.bundle, &p->ainsn.insn.bundle, sizeof(bundle_t));
+ if (bundle_encoding[template][slot] == I) {
+ switch (major_opcode) {
+ case 0x0: //I_UNIT_MISC_OPCODE:
+ /*
+ * Check for Integer speculation instruction
+ * - Bit 33-35 to be equal to 0x1
+ */
+ if (((kprobe_inst >> 33) & 0x7) == 1) {
+ printk(KERN_WARNING
+ "Kprobes on speculation inst at <0x%lx> not supported\n",
+ addr);
+ return -EINVAL;
+ }
+
+ /*
+ * IP relative mov instruction
+ * - Bit 27-35 to be equal to 0x30
+ */
+ if (((kprobe_inst >> 27) & 0x1FF) == 0x30) {
+ printk(KERN_WARNING
+ "Kprobes on \"mov r1=ip\" at <0x%lx> not supported\n",
+ addr);
+ return -EINVAL;
+
+ }
+ }
+ }
+ return 0;
+}
+
+
+/*
+ * In this function we check to see if the instruction
+ * (qp) cmpx.crel.ctype p1,p2=r2,r3
+ * on which we are inserting kprobe is cmp instruction
+ * with ctype as unc.
+ */
+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;
+
+ if (!((bundle_encoding[template][slot] == I) ||
+ (bundle_encoding[template][slot] == M)))
+ goto out;
+
+ if (!((major_opcode == 0xC) || (major_opcode == 0xD) ||
+ (major_opcode == 0xE)))
+ goto out;
+
+ cmp_inst.l = kprobe_inst;
+ if ((cmp_inst.f.x2 == 0) || (cmp_inst.f.x2 == 1)) {
+ /* Integere compare - Register Register (A6 type)*/
+ if ((cmp_inst.f.tb == 0) && (cmp_inst.f.ta == 0)
+ &&(cmp_inst.f.c == 1))
+ ctype_unc = 1;
+ } else if ((cmp_inst.f.x2 == 2)||(cmp_inst.f.x2 == 3)) {
+ /* Integere compare - Immediate Register (A8 type)*/
+ if ((cmp_inst.f.ta == 0) &&(cmp_inst.f.c == 1))
+ ctype_unc = 1;
+ }
+out:
+ return ctype_unc;
}
-void arch_arm_kprobe(struct kprobe *p)
+/*
+ * In this function we override the bundle with
+ * the break instruction at the given slot.
+ */
+static void __kprobes prepare_break_inst(uint template, uint slot,
+ uint major_opcode,
+ unsigned long kprobe_inst,
+ struct kprobe *p)
{
- unsigned long addr = (unsigned long)p->addr;
- unsigned long arm_addr = addr & ~0xFULL;
- unsigned long slot = addr & 0xf;
- unsigned long template;
- bundle_t bundle;
+ unsigned long break_inst = BREAK_INST;
+ bundle_t *bundle = &p->ainsn.insn.bundle;
- memcpy(&bundle, &p->ainsn.insn.bundle, sizeof(bundle_t));
+ /*
+ * Copy the original kprobe_inst qualifying predicate(qp)
+ * to the break instruction iff !is_cmp_ctype_unc_inst
+ * because for cmp instruction with ctype equal to unc,
+ * which is a special instruction always needs to be
+ * executed regradless of qp
+ */
+ if (!is_cmp_ctype_unc_inst(template, slot, major_opcode, kprobe_inst))
+ break_inst |= (0x3f & kprobe_inst);
- template = bundle.quad0.template;
- if (slot == 1 && bundle_encoding[template][1] == L)
- slot = 2;
switch (slot) {
- case 0:
- bundle.quad0.slot0 = BREAK_INST;
+ case 0:
+ bundle->quad0.slot0 = break_inst;
break;
- case 1:
- bundle.quad0.slot1_p0 = BREAK_INST;
- bundle.quad1.slot1_p1 = (BREAK_INST >> (64-46));
+ case 1:
+ bundle->quad0.slot1_p0 = break_inst;
+ bundle->quad1.slot1_p1 = break_inst >> (64-46);
break;
- case 2:
- bundle.quad1.slot2 = BREAK_INST;
+ case 2:
+ bundle->quad1.slot2 = break_inst;
break;
}
- /* Flush icache for the instruction at the emulated address */
- flush_icache_range((unsigned long)&p->ainsn.insn.bundle,
- (unsigned long)&p->ainsn.insn.bundle +
- sizeof(bundle_t));
/*
- * Patch the original instruction with the probe instruction
- * and flush the instruction cache
+ * Update the instruction flag, so that we can
+ * emulate the instruction properly after we
+ * single step on original instruction
*/
- memcpy((char *) arm_addr, (char *) &bundle, sizeof(bundle_t));
+ update_kprobe_inst_flag(template, slot, major_opcode, kprobe_inst, p);
+}
+
+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;
+ unsigned int template;
+
+ template = bundle->quad0.template;
+
+ switch (slot) {
+ case 0:
+ *major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT);
+ *kprobe_inst = bundle->quad0.slot0;
+ break;
+ case 1:
+ *major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT);
+ kprobe_inst_p0 = bundle->quad0.slot1_p0;
+ kprobe_inst_p1 = bundle->quad1.slot1_p1;
+ *kprobe_inst = kprobe_inst_p0 | (kprobe_inst_p1 << (64-46));
+ break;
+ case 2:
+ *major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT);
+ *kprobe_inst = bundle->quad1.slot2;
+ break;
+ }
+}
+
+/* Returns non-zero if the addr is in the Interrupt Vector Table */
+static int __kprobes 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);
+ 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;
+}
+
+static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
+{
+ kcb->prev_kprobe.kp = kprobe_running();
+ kcb->prev_kprobe.status = kcb->kprobe_status;
+}
+
+static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
+{
+ __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+ kcb->kprobe_status = kcb->prev_kprobe.status;
+}
+
+static void __kprobes set_current_kprobe(struct kprobe *p,
+ struct kprobe_ctlblk *kcb)
+{
+ __get_cpu_var(current_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 flags, orig_ret_address = 0;
+ unsigned long trampoline_address =
+ ((struct fnptr *)kretprobe_trampoline)->ip;
+
+ spin_lock_irqsave(&kretprobe_lock, flags);
+ 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;
+
+ 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 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)
+{
+ 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);
+ unsigned long kprobe_inst=0;
+ unsigned int slot = addr & 0xf, template, major_opcode = 0;
+ bundle_t *bundle = &p->ainsn.insn.bundle;
+
+ memcpy(&p->opcode.bundle, kprobe_addr, sizeof(bundle_t));
+ memcpy(&p->ainsn.insn.bundle, kprobe_addr, sizeof(bundle_t));
+
+ template = bundle->quad0.template;
+
+ if(valid_kprobe_addr(template, slot, addr))
+ return -EINVAL;
+
+ /* 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_inst and major_opcode from the bundle */
+ get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode);
+
+ if (unsupported_inst(template, slot, major_opcode, kprobe_inst, p))
+ return -EINVAL;
+
+ prepare_break_inst(template, slot, major_opcode, kprobe_inst, p);
+
+ 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 arch_disarm_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;
- /* p->opcode contains the original unaltered bundle */
- memcpy((char *) arm_addr, (char *) &p->opcode.bundle, sizeof(bundle_t));
+ 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));
}
-void arch_remove_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;
+
+ /* p->opcode contains the original unaltered bundle */
+ memcpy((char *) arm_addr, (char *) &p->opcode.bundle, sizeof(bundle_t));
+ flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
}
/*
* We are resuming execution after a single step fault, so the pt_regs
* structure reflects the register state after we executed the instruction
* located in the kprobe (p->ainsn.insn.bundle). We still need to adjust
- * the ip to point back to the original stack address, and if we see that
- * the slot has incremented back to zero, then we need to point to the next
- * slot location.
+ * the ip to point back to the original stack address. To set the IP address
+ * 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 = (unsigned long)p->addr & ~0xFULL;
+ unsigned long bundle_addr = ((unsigned long) (&p->opcode.bundle)) & ~0xFULL;
+ unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL;
+ unsigned long template;
+ int slot = ((unsigned long)p->addr & 0xf);
- /*
- * TODO: Handle cases where kprobe was inserted on a branch instruction
- */
+ template = p->opcode.bundle.quad0.template;
- if (!ia64_psr(regs)->ri)
- regs->cr_iip = bundle + 0x10;
- else
- regs->cr_iip = bundle;
+ if (slot == 1 && bundle_encoding[template][1] == L)
+ slot = 2;
+
+ if (p->ainsn.inst_flag) {
- ia64_psr(regs)->ss = 0;
+ if (p->ainsn.inst_flag & INST_FLAG_FIX_RELATIVE_IP_ADDR) {
+ /* Fix relative IP address */
+ regs->cr_iip = (regs->cr_iip - bundle_addr) + resume_addr;
+ }
+
+ if (p->ainsn.inst_flag & INST_FLAG_FIX_BRANCH_REG) {
+ /*
+ * Fix target branch register, software convention is
+ * to use either b0 or b6 or b7, so just checking
+ * only those registers
+ */
+ switch (p->ainsn.target_br_reg) {
+ case 0:
+ if ((regs->b0 == bundle_addr) ||
+ (regs->b0 == bundle_addr + 0x10)) {
+ regs->b0 = (regs->b0 - bundle_addr) +
+ resume_addr;
+ }
+ break;
+ case 6:
+ if ((regs->b6 == bundle_addr) ||
+ (regs->b6 == bundle_addr + 0x10)) {
+ regs->b6 = (regs->b6 - bundle_addr) +
+ resume_addr;
+ }
+ break;
+ case 7:
+ if ((regs->b7 == bundle_addr) ||
+ (regs->b7 == bundle_addr + 0x10)) {
+ regs->b7 = (regs->b7 - bundle_addr) +
+ resume_addr;
+ }
+ break;
+ } /* end switch */
+ }
+ goto turn_ss_off;
+ }
+
+ if (slot == 2) {
+ if (regs->cr_iip == bundle_addr + 0x10) {
+ regs->cr_iip = resume_addr + 0x10;
+ }
+ } else {
+ if (regs->cr_iip == bundle_addr) {
+ regs->cr_iip = resume_addr;
+ }
+ }
+
+turn_ss_off:
+ /* Turn off Single Step bit */
+ 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->ainsn.insn.bundle;
+ 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 pt_regs *regs)
+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);
+ 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) {
- unlock_kprobes();
+ if ((kcb->kprobe_status == KPROBE_HIT_SS) &&
+ (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) {
+ ia64_psr(regs)->ss = 0;
goto no_kprobe;
}
- arch_disarm_kprobe(p);
- ret = 1;
- } else {
+ /* We have reentered the pre_kprobe_handler(), since
+ * another probe was hit while within the handler.
+ * We here save the original kprobes variables and
+ * just single step on the instruction of the new probe
+ * without calling any user handlers.
+ */
+ save_previous_kprobe(kcb);
+ set_current_kprobe(p, kcb);
+ kprobes_inc_nmissed_count(p);
+ prepare_ss(p, regs);
+ 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
+ * 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;
}
- kprobe_status = KPROBE_HIT_ACTIVE;
- current_kprobe = p;
+ set_current_kprobe(p, kcb);
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
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;
ss_probe:
prepare_ss(p, regs);
- kprobe_status = KPROBE_HIT_SS;
+ kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
no_kprobe:
return ret;
}
-static int post_kprobes_handler(struct pt_regs *regs)
+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 (current_kprobe->post_handler)
- 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);
- unlock_kprobes();
+ /*Restore back the original saved kprobes variables and continue. */
+ if (kcb->kprobe_status == KPROBE_REENTER) {
+ restore_previous_kprobe(kcb);
+ goto out;
+ }
+ reset_current_kprobe();
+
+out:
preempt_enable_no_resched();
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;
+ 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;
}
-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;
+
+ if (args->regs && user_mode(args->regs))
+ return ret;
+
switch(val) {
case DIE_BREAK:
- if (pre_kprobes_handler(args->regs))
- return 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))
- return 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))
- return NOTIFY_STOP;
+ /* 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;
}
- return NOTIFY_DONE;
+ return ret;
}
-int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
+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)
{
- printk(KERN_WARNING "Jprobes is not supported\n");
- return 0;
+ 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;
}
-void jprobe_return(void)
+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 */
+ kcb->jprobe_saved_regs = *regs;
+
+ /* after rfi, execute the jprobe instrumented function */
+ regs->cr_iip = addr & ~0xFULL;
+ ia64_psr(regs)->ri = addr & 0xf;
+ regs->r1 = ((struct fnptr *)(jp->entry))->gp;
+
+ /*
+ * fix the return address to our jprobe_inst_return() function
+ * in the jprobes.S file
+ */
+ regs->b0 = ((struct fnptr *)(jprobe_inst_return))->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)
{
- return 0;
+ 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;
+}
+
+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);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff