* <anil.s.keshavamurthy@intel.com> adapted from i386
*/
-#include <linux/config.h>
#include <linux/kprobes.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/preempt.h>
#include <linux/moduleloader.h>
+#include <linux/kdebug.h>
#include <asm/pgtable.h>
-#include <asm/kdebug.h>
#include <asm/sections.h>
+#include <asm/uaccess.h>
extern void jprobe_inst_return(void);
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};
+
enum instruction_type {A, I, M, F, B, L, X, u};
static enum instruction_type bundle_encoding[32][3] = {
{ M, I, I }, /* 00 */
{ u, u, u }, /* 1F */
};
+/* Insert a long branch code */
+static void __kprobes set_brl_inst(void *from, void *to)
+{
+ s64 rel = ((s64) to - (s64) from) >> 4;
+ bundle_t *brl;
+ brl = (bundle_t *) ((u64) from & ~0xf);
+ brl->quad0.template = 0x05; /* [MLX](stop) */
+ brl->quad0.slot0 = NOP_M_INST; /* nop.m 0x0 */
+ brl->quad0.slot1_p0 = ((rel >> 20) & 0x7fffffffff) << 2;
+ brl->quad1.slot1_p1 = (((rel >> 20) & 0x7fffffffff) << 2) >> (64 - 46);
+ /* brl.cond.sptk.many.clr rel<<4 (qp=0) */
+ brl->quad1.slot2 = BRL_INST(rel >> 59, rel & 0xfffff);
+}
+
/*
* In this function we check to see if the instruction
* is IP relative instruction and update the kprobe
{
p->ainsn.inst_flag = 0;
p->ainsn.target_br_reg = 0;
+ p->ainsn.slot = slot;
/* Check for Break instruction
- * Bits 37:40 Major opcode to be zero
+ * Bits 37:40 Major opcode to be zero
* Bits 27:32 X6 to be zero
* Bits 32:35 X3 to be zero
*/
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;
+ 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;
+ 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;
+ 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) {
+ } else if (bundle_encoding[template][slot] == X) {
switch (major_opcode) {
case LONG_CALL_OPCODE:
p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
/*
* 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)) {
+ /* Integer 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)) {
+ /* Integer compare - Immediate Register (A8 type)*/
+ if ((cmp_inst.f.ta == 0) &&(cmp_inst.f.c == 1))
+ ctype_unc = 1;
+ }
+out:
+ return ctype_unc;
+}
+
+/*
+ * In this function we check to see if the instruction
* on which we are inserting kprobe is supported.
- * Returns 0 if supported
+ * Returns qp value 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 addr = (unsigned long)p->addr;
+ int qp;
+
+ qp = kprobe_inst & 0x3f;
+ if (is_cmp_ctype_unc_inst(template, slot, major_opcode, kprobe_inst)) {
+ if (slot == 1 && qp) {
+ printk(KERN_WARNING "Kprobes on cmp unc "
+ "instruction on slot 1 at <0x%lx> "
+ "is not supported\n", addr);
+ return -EINVAL;
- if (bundle_encoding[template][slot] == I) {
- switch (major_opcode) {
- case 0x0: //I_UNIT_MISC_OPCODE:
+ }
+ qp = 0;
+ }
+ else if (bundle_encoding[template][slot] == I) {
+ if (major_opcode == 0) {
/*
* 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);
+ 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);
+ addr);
return -EINVAL;
}
}
+ else if ((major_opcode == 5) && !(kprobe_inst & (0xFUl << 33)) &&
+ (kprobe_inst & (0x1UL << 12))) {
+ /* test bit instructions, tbit,tnat,tf
+ * bit 33-36 to be equal to 0
+ * bit 12 to be equal to 1
+ */
+ if (slot == 1 && qp) {
+ printk(KERN_WARNING "Kprobes on test bit "
+ "instruction on slot at <0x%lx> "
+ "is not supported\n", addr);
+ return -EINVAL;
+ }
+ qp = 0;
+ }
}
- 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;
+ else if (bundle_encoding[template][slot] == B) {
+ if (major_opcode == 7) {
+ /* IP-Relative Predict major code is 7 */
+ printk(KERN_WARNING "Kprobes on IP-Relative"
+ "Predict is not supported\n");
+ return -EINVAL;
+ }
+ else if (major_opcode == 2) {
+ /* Indirect Predict, major code is 2
+ * bit 27-32 to be equal to 10 or 11
+ */
+ int x6=(kprobe_inst >> 27) & 0x3F;
+ if ((x6 == 0x10) || (x6 == 0x11)) {
+ printk(KERN_WARNING "Kprobes on "
+ "Indirect Predict is not supported\n");
+ return -EINVAL;
+ }
+ }
+ }
+ /* kernel does not use float instruction, here for safety kprobe
+ * will judge whether it is fcmp/flass/float approximation instruction
+ */
+ else if (unlikely(bundle_encoding[template][slot] == F)) {
+ if ((major_opcode == 4 || major_opcode == 5) &&
+ (kprobe_inst & (0x1 << 12))) {
+ /* fcmp/fclass unc instruction */
+ if (slot == 1 && qp) {
+ printk(KERN_WARNING "Kprobes on fcmp/fclass "
+ "instruction on slot at <0x%lx> "
+ "is not supported\n", addr);
+ return -EINVAL;
- 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;
+ }
+ qp = 0;
+ }
+ if ((major_opcode == 0 || major_opcode == 1) &&
+ (kprobe_inst & (0x1UL << 33))) {
+ /* float Approximation instruction */
+ if (slot == 1 && qp) {
+ printk(KERN_WARNING "Kprobes on float Approx "
+ "instr at <0x%lx> is not supported\n",
+ addr);
+ return -EINVAL;
+ }
+ qp = 0;
+ }
}
-out:
- return ctype_unc;
+ return qp;
}
/*
static void __kprobes prepare_break_inst(uint template, uint slot,
uint major_opcode,
unsigned long kprobe_inst,
- struct kprobe *p)
+ struct kprobe *p,
+ int qp)
{
unsigned long break_inst = BREAK_INST;
- bundle_t *bundle = &p->ainsn.insn.bundle;
+ bundle_t *bundle = &p->opcode.bundle;
/*
* 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
+ * to the break instruction
*/
- if (!is_cmp_ctype_unc_inst(template, slot, major_opcode, kprobe_inst))
- break_inst |= (0x3f & kprobe_inst);
+ break_inst |= qp;
switch (slot) {
case 0:
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;
switch (slot) {
case 0:
- *major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT);
- *kprobe_inst = bundle->quad0.slot0;
- break;
+ *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));
+ *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;
+ *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 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 -EINVAL;
}
- if (in_ivt_functions(addr)) {
- printk(KERN_WARNING "Kprobes can't be inserted inside "
+ 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 inline void save_previous_kprobe(struct kprobe_ctlblk *kcb)
+static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
{
- kcb->prev_kprobe.kp = kprobe_running();
- kcb->prev_kprobe.status = kcb->kprobe_status;
+ unsigned int i;
+ i = atomic_add_return(1, &kcb->prev_kprobe_index);
+ kcb->prev_kprobe[i-1].kp = kprobe_running();
+ kcb->prev_kprobe[i-1].status = kcb->kprobe_status;
}
-static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
+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;
+ unsigned int i;
+ i = atomic_read(&kcb->prev_kprobe_index);
+ __get_cpu_var(current_kprobe) = kcb->prev_kprobe[i-1].kp;
+ kcb->kprobe_status = kcb->prev_kprobe[i-1].status;
+ atomic_sub(1, &kcb->prev_kprobe_index);
}
-static inline void set_current_kprobe(struct kprobe *p,
+static void __kprobes set_current_kprobe(struct kprobe *p,
struct kprobe_ctlblk *kcb)
{
__get_cpu_var(current_kprobe) = p;
int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
struct kretprobe_instance *ri = NULL;
- struct hlist_head *head;
+ struct hlist_head *head, empty_rp;
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);
+ INIT_HLIST_HEAD(&empty_rp);
+ kretprobe_hash_lock(current, &head, &flags);
/*
* 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;
+
+ orig_ret_address = (unsigned long)ri->ret_addr;
+ 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;
+ }
+
+ regs->cr_iip = orig_ret_address;
+
+ 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);
+ recycle_rp_inst(ri, &empty_rp);
if (orig_ret_address != trampoline_address)
/*
break;
}
- BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address));
- regs->cr_iip = orig_ret_address;
+ kretprobe_assert(ri, orig_ret_address, trampoline_address);
reset_current_kprobe();
- spin_unlock_irqrestore(&kretprobe_lock, flags);
+ kretprobe_hash_unlock(current, &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;
+ hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
+ hlist_del(&ri->hlist);
+ kfree(ri);
+ }
+ /*
+ * 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,
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- struct kretprobe_instance *ri;
+ ri->ret_addr = (kprobe_opcode_t *)regs->b0;
+
+ /* Replace the return addr with trampoline addr */
+ regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
+}
- if ((ri = get_free_rp_inst(rp)) != NULL) {
- ri->rp = rp;
- ri->task = current;
- ri->ret_addr = (kprobe_opcode_t *)regs->b0;
+/* Check the instruction in the slot is break */
+static int __kprobes __is_ia64_break_inst(bundle_t *bundle, uint slot)
+{
+ unsigned int major_opcode;
+ unsigned int template = bundle->quad0.template;
+ unsigned long kprobe_inst;
- /* Replace the return addr with trampoline addr */
- regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
+ /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
+ if (slot == 1 && bundle_encoding[template][1] == L)
+ slot++;
- add_rp_inst(ri);
- } else {
- rp->nmissed++;
+ /* 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;
+}
+
+/*
+ * In this function, we check whether the target bundle modifies IP or
+ * it triggers an exception. If so, it cannot be boostable.
+ */
+static int __kprobes can_boost(bundle_t *bundle, uint slot,
+ unsigned long bundle_addr)
+{
+ unsigned int template = bundle->quad0.template;
+
+ do {
+ if (search_exception_tables(bundle_addr + slot) ||
+ __is_ia64_break_inst(bundle, slot))
+ return 0; /* exception may occur in this bundle*/
+ } while ((++slot) < 3);
+ template &= 0x1e;
+ if (template >= 0x10 /* including B unit */ ||
+ template == 0x04 /* including X unit */ ||
+ template == 0x06) /* undefined */
+ return 0;
+
+ return 1;
+}
+
+/* Prepare long jump bundle and disables other boosters if need */
+static void __kprobes prepare_booster(struct kprobe *p)
+{
+ unsigned long addr = (unsigned long)p->addr & ~0xFULL;
+ unsigned int slot = (unsigned long)p->addr & 0xf;
+ struct kprobe *other_kp;
+
+ if (can_boost(&p->ainsn.insn[0].bundle, slot, addr)) {
+ set_brl_inst(&p->ainsn.insn[1].bundle, (bundle_t *)addr + 1);
+ p->ainsn.inst_flag |= INST_FLAG_BOOSTABLE;
+ }
+
+ /* disables boosters in previous slots */
+ for (; addr < (unsigned long)p->addr; addr++) {
+ other_kp = get_kprobe((void *)addr);
+ if (other_kp)
+ other_kp->ainsn.inst_flag &= ~INST_FLAG_BOOSTABLE;
}
}
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;
+ bundle_t *bundle;
+ int qp;
- memcpy(&p->opcode.bundle, kprobe_addr, sizeof(bundle_t));
- memcpy(&p->ainsn.insn.bundle, kprobe_addr, sizeof(bundle_t));
-
- template = bundle->quad0.template;
+ bundle = &((kprobe_opcode_t *)kprobe_addr)->bundle;
+ 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++;
+ 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;
+ qp = unsupported_inst(template, slot, major_opcode, kprobe_inst, addr);
+ if (qp < 0)
+ return -EINVAL;
+
+ p->ainsn.insn = get_insn_slot();
+ if (!p->ainsn.insn)
+ return -ENOMEM;
+ memcpy(&p->opcode, kprobe_addr, sizeof(kprobe_opcode_t));
+ memcpy(p->ainsn.insn, kprobe_addr, sizeof(kprobe_opcode_t));
- prepare_break_inst(template, slot, major_opcode, kprobe_inst, p);
+ prepare_break_inst(template, slot, major_opcode, kprobe_inst, p, qp);
+
+ prepare_booster(p);
return 0;
}
void __kprobes arch_arm_kprobe(struct kprobe *p)
{
- unsigned long addr = (unsigned long)p->addr;
- unsigned long arm_addr = addr & ~0xFULL;
+ unsigned long arm_addr;
+ bundle_t *src, *dest;
+
+ arm_addr = ((unsigned long)p->addr) & ~0xFUL;
+ dest = &((kprobe_opcode_t *)arm_addr)->bundle;
+ src = &p->opcode.bundle;
- memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t));
- flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
+ flush_icache_range((unsigned long)p->ainsn.insn,
+ (unsigned long)p->ainsn.insn +
+ sizeof(kprobe_opcode_t) * MAX_INSN_SIZE);
+
+ switch (p->ainsn.slot) {
+ case 0:
+ dest->quad0.slot0 = src->quad0.slot0;
+ break;
+ case 1:
+ dest->quad1.slot1_p1 = src->quad1.slot1_p1;
+ break;
+ case 2:
+ dest->quad1.slot2 = src->quad1.slot2;
+ break;
+ }
+ flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
}
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));
+ unsigned long arm_addr;
+ bundle_t *src, *dest;
+
+ arm_addr = ((unsigned long)p->addr) & ~0xFUL;
+ dest = &((kprobe_opcode_t *)arm_addr)->bundle;
+ /* p->ainsn.insn contains the original unaltered kprobe_opcode_t */
+ src = &p->ainsn.insn->bundle;
+ switch (p->ainsn.slot) {
+ case 0:
+ dest->quad0.slot0 = src->quad0.slot0;
+ break;
+ case 1:
+ dest->quad1.slot1_p1 = src->quad1.slot1_p1;
+ break;
+ case 2:
+ dest->quad1.slot2 = src->quad1.slot2;
+ break;
+ }
+ flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
}
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
+ mutex_lock(&kprobe_mutex);
+ free_insn_slot(p->ainsn.insn, p->ainsn.inst_flag & INST_FLAG_BOOSTABLE);
+ mutex_unlock(&kprobe_mutex);
}
-
/*
* 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
+ * located in the kprobe (p->ainsn.insn->bundle). We still need to adjust
* 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 __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;
- unsigned long template;
- int slot = ((unsigned long)p->addr & 0xf);
+ unsigned long bundle_addr = (unsigned long) (&p->ainsn.insn->bundle);
+ unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL;
+ unsigned long template;
+ int slot = ((unsigned long)p->addr & 0xf);
- template = p->opcode.bundle.quad0.template;
+ template = p->ainsn.insn->bundle.quad0.template;
- if (slot == 1 && bundle_encoding[template][1] == L)
- slot = 2;
+ if (slot == 1 && bundle_encoding[template][1] == L)
+ slot = 2;
- if (p->ainsn.inst_flag) {
+ if (p->ainsn.inst_flag & ~INST_FLAG_BOOSTABLE) {
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;
+ regs->cr_iip = (regs->cr_iip - bundle_addr) +
+ resume_addr;
}
if (p->ainsn.inst_flag & INST_FLAG_FIX_BRANCH_REG) {
}
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;
- }
+ 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;
+ /* Turn off Single Step bit */
+ ia64_psr(regs)->ss = 0;
}
static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs)
{
- unsigned long bundle_addr = (unsigned long) &p->opcode.bundle;
+ unsigned long bundle_addr = (unsigned long) &p->ainsn.insn->bundle;
unsigned long slot = (unsigned long)p->addr & 0xf;
/* single step inline if break instruction */
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;
+ return __is_ia64_break_inst(&bundle, slot);
}
static int __kprobes pre_kprobes_handler(struct die_args *args)
int ret = 0;
struct pt_regs *regs = args->regs;
kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs);
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ 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()) {
if (p) {
if ((kcb->kprobe_status == KPROBE_HIT_SS) &&
(p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) {
- ia64_psr(regs)->ss = 0;
+ ia64_psr(regs)->ss = 0;
goto no_kprobe;
}
/* We have reentered the pre_kprobe_handler(), since
*/
save_previous_kprobe(kcb);
set_current_kprobe(p, kcb);
- p->nmissed++;
+ kprobes_inc_nmissed_count(p);
prepare_ss(p, regs);
kcb->kprobe_status = KPROBE_REENTER;
return 1;
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;
goto no_kprobe;
}
- /*
- * This preempt_disable() matches the preempt_enable_no_resched()
- * in post_kprobes_handler()
- */
- preempt_disable();
set_current_kprobe(p, kcb);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
return 1;
ss_probe:
+#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM)
+ if (p->ainsn.inst_flag == INST_FLAG_BOOSTABLE && !p->post_handler) {
+ /* Boost up -- we can execute copied instructions directly */
+ ia64_psr(regs)->ri = p->ainsn.slot;
+ regs->cr_iip = (unsigned long)&p->ainsn.insn->bundle & ~0xFULL;
+ /* turn single stepping off */
+ ia64_psr(regs)->ss = 0;
+
+ reset_current_kprobe();
+ preempt_enable_no_resched();
+ return 1;
+ }
+#endif
prepare_ss(p, regs);
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
no_kprobe:
+ preempt_enable_no_resched();
return ret;
}
return 1;
}
-static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- if (!cur)
- return 0;
-
- if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
- return 1;
- if (kcb->kprobe_status & KPROBE_HIT_SS) {
- resume_execution(cur, regs);
- reset_current_kprobe();
+ 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;
+ /*
+ * In case the user-specified fault handler returned
+ * zero, try to fix up.
+ */
+ if (ia64_done_with_exception(regs))
+ 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;
- rcu_read_lock();
+ 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 >> 12) == (__IA64_BREAK_KPROBE >> 12)
+ || args->err == __IA64_BREAK_JPROBE
+ || 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))
- ret = NOTIFY_STOP;
default:
break;
}
- rcu_read_unlock();
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 = NULL;
+ lp->cfm = 0;
+ return;
+}
+
+unsigned long arch_deref_entry_point(void *entry)
+{
+ return ((struct fnptr *)entry)->ip;
+}
+
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;
+ unsigned long addr = arch_deref_entry_point(jp->entry);
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 transferring 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;
* fix the return address to our jprobe_inst_return() function
* in the jprobes.S file
*/
- regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip;
+ regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip;
return 1;
}
+/* ia64 does not need this */
+void __kprobes jprobe_return(void)
+{
+}
+
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *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;
}
(kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip;
return register_kprobe(&trampoline_p);
}
+
+int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+{
+ if (p->addr ==
+ (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip)
+ return 1;
+
+ return 0;
+}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff