diff options
Diffstat (limited to 'arch/ia64/kernel/kprobes.c')
| -rw-r--r-- | arch/ia64/kernel/kprobes.c | 806 |
1 files changed, 572 insertions, 234 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 471086b808a..074fde49c9e 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -23,28 +23,24 @@ * <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 <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); -/* kprobe_status settings */ -#define KPROBE_HIT_ACTIVE 0x00000001 -#define KPROBE_HIT_SS 0x00000002 +DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; +DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); -static struct kprobe *current_kprobe, *kprobe_prev; -static unsigned long kprobe_status, kprobe_status_prev; -static struct pt_regs jprobe_saved_regs; +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] = { @@ -82,6 +78,20 @@ static enum instruction_type bundle_encoding[32][3] = { { 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 @@ -94,9 +104,10 @@ static void __kprobes update_kprobe_inst_flag(uint template, uint slot, { 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 */ @@ -110,19 +121,19 @@ static void __kprobes update_kprobe_inst_flag(uint template, uint slot, 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; @@ -135,20 +146,66 @@ static void __kprobes update_kprobe_inst_flag(uint template, uint slot, /* * 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 @@ -156,10 +213,9 @@ static int __kprobes unsupported_inst(uint template, uint slot, 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 @@ -167,50 +223,74 @@ static int __kprobes unsupported_inst(uint template, uint slot, 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; } /* @@ -220,20 +300,17 @@ out: 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: @@ -256,7 +333,7 @@ static void __kprobes prepare_break_inst(uint template, uint slot, 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; @@ -266,24 +343,24 @@ static inline void get_kprobe_inst(bundle_t *bundle, uint slot, 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); @@ -298,36 +375,36 @@ static int __kprobes valid_kprobe_addr(int template, int slot, 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(void) +static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) { - kprobe_prev = current_kprobe; - kprobe_status_prev = 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(void) +static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) { - current_kprobe = kprobe_prev; - kprobe_status = kprobe_status_prev; + 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) { - current_kprobe = p; + __get_cpu_var(current_kprobe) = p; } static void kretprobe_trampoline(void) @@ -345,18 +422,19 @@ static void kretprobe_trampoline(void) 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; + struct hlist_head *head, empty_rp; + struct hlist_node *tmp; + unsigned long flags, orig_ret_address = 0; unsigned long trampoline_address = ((struct fnptr *)kretprobe_trampoline)->ip; - 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 * task either because an multiple functions in the call path - * have a return probe installed on them, and/or more then one return + * have a return probe installed on them, and/or more than one return * return probe was registered for a target function. * * We can handle this because: @@ -366,16 +444,33 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) * 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) + hlist_for_each_entry_safe(ri, tmp, head, hlist) { + if (ri->task != current) + /* another task is sharing our hash bucket */ + 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, tmp, head, hlist) { + if (ri->task != current) /* another task is sharing our hash bucket */ - continue; + 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) /* @@ -386,36 +481,101 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) 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); - unlock_kprobes(); + reset_current_kprobe(); + 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, 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; } -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; } } @@ -425,79 +585,123 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) 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)); + bundle_t *bundle; + int qp; - 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; - prepare_break_inst(template, slot, major_opcode, kprobe_inst, p); + 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, 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; + + flush_icache_range((unsigned long)p->ainsn.insn, + (unsigned long)p->ainsn.insn + + sizeof(kprobe_opcode_t) * MAX_INSN_SIZE); - memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t)); - flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t)); + 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) { + if (p->ainsn.insn) { + free_insn_slot(p->ainsn.insn, + p->ainsn.inst_flag & INST_FLAG_BOOSTABLE); + p->ainsn.insn = NULL; + } } - /* * 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) { @@ -534,23 +738,23 @@ static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) } 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 */ @@ -571,33 +775,12 @@ static void __kprobes prepare_ss(struct kprobe *p, 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; + return __is_ia64_break_inst(&bundle, slot); } static int __kprobes pre_kprobes_handler(struct die_args *args) @@ -606,17 +789,22 @@ 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; + /* + * 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(); + ia64_psr(regs)->ss = 0; goto no_kprobe; } /* We have reentered the pre_kprobe_handler(), since @@ -625,30 +813,35 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) * 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 @@ -665,8 +858,8 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) goto no_kprobe; } - 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)) /* @@ -677,8 +870,21 @@ static int __kprobes pre_kprobes_handler(struct die_args *args) return 1; ss_probe: +#if !defined(CONFIG_PREEMPT) + 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); - kprobe_status = KPROBE_HIT_SS; + kcb->kprobe_status = KPROBE_HIT_SS; return 1; no_kprobe: @@ -688,42 +894,86 @@ no_kprobe: 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(); 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) { - 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 accounting + * 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; @@ -733,31 +983,90 @@ 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)) - return 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)) - 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; default: break; } - return NOTIFY_DONE; + 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 */ - jprobe_saved_regs = *regs; + kcb->jprobe_saved_regs = *regs; /* after rfi, execute the jprobe instrumented function */ regs->cr_iip = addr & ~0xFULL; @@ -768,14 +1077,34 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_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) { - *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; } @@ -789,3 +1118,12 @@ int __init arch_init_kprobes(void) (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; +} |