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[PATCH] Kprobes IA64: arch_prepare_kprobes() cleanup
arch_prepare_kprobes() was doing lots of functionality in just one single function. This patch attempts to clean up arch_prepare_kprobes() by moving specific sub task to the following (new)functions 1)valid_kprobe_addr() -->> validate the given kprobe address 2)get_kprobe_inst(slot..)->> Retrives the instruction for a given slot from the bundle 3)prepare_break_inst() -->> Prepares break instruction within the bundle 3a)update_kprobe_inst_flag()-->>Updates the internal flags, required for proper emulation of the instruction at later point in time. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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a5403183d8
@ -81,90 +81,141 @@ static enum instruction_type bundle_encoding[32][3] = {
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{ u, u, u }, /* 1F */
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};
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int arch_prepare_kprobe(struct kprobe *p)
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/*
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* In this function we check to see if the instruction
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* is IP relative instruction and update the kprobe
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* inst flag accordingly
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*/
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static void update_kprobe_inst_flag(uint template, uint slot, uint major_opcode,
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unsigned long kprobe_inst, struct kprobe *p)
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{
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unsigned long addr = (unsigned long) p->addr;
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unsigned long *bundle_addr = (unsigned long *)(addr & ~0xFULL);
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unsigned long slot = addr & 0xf;
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unsigned long template;
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unsigned long major_opcode = 0;
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unsigned long lx_type_inst = 0;
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unsigned long kprobe_inst = 0;
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bundle_t *bundle = &p->ainsn.insn.bundle;
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memcpy(&p->opcode.bundle, bundle_addr, sizeof(bundle_t));
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memcpy(&p->ainsn.insn.bundle, bundle_addr, sizeof(bundle_t));
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p->ainsn.inst_flag = 0;
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p->ainsn.target_br_reg = 0;
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template = bundle->quad0.template;
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if (bundle_encoding[template][slot] == B) {
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switch (major_opcode) {
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case INDIRECT_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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case IP_RELATIVE_PREDICT_OPCODE:
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case IP_RELATIVE_BRANCH_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
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break;
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case IP_RELATIVE_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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}
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} else if (bundle_encoding[template][slot] == X) {
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switch (major_opcode) {
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case LONG_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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}
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}
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return;
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}
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if (((bundle_encoding[template][1] == L) && slot > 1) || (slot > 2)) {
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/*
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* In this function we override the bundle with
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* the break instruction at the given slot.
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*/
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static void prepare_break_inst(uint template, uint slot, uint major_opcode,
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unsigned long kprobe_inst, struct kprobe *p)
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{
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unsigned long break_inst = BREAK_INST;
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bundle_t *bundle = &p->ainsn.insn.bundle;
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/*
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* Copy the original kprobe_inst qualifying predicate(qp)
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* to the break instruction
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*/
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break_inst |= (0x3f & kprobe_inst);
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switch (slot) {
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case 0:
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bundle->quad0.slot0 = break_inst;
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break;
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case 1:
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bundle->quad0.slot1_p0 = break_inst;
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bundle->quad1.slot1_p1 = break_inst >> (64-46);
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break;
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case 2:
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bundle->quad1.slot2 = break_inst;
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break;
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}
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/*
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* Update the instruction flag, so that we can
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* emulate the instruction properly after we
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* single step on original instruction
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*/
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update_kprobe_inst_flag(template, slot, major_opcode, kprobe_inst, p);
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}
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static inline void get_kprobe_inst(bundle_t *bundle, uint slot,
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unsigned long *kprobe_inst, uint *major_opcode)
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{
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unsigned long kprobe_inst_p0, kprobe_inst_p1;
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unsigned int template;
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template = bundle->quad0.template;
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switch (slot) {
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case 0:
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*major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT);
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*kprobe_inst = bundle->quad0.slot0;
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break;
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case 1:
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*major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT);
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kprobe_inst_p0 = bundle->quad0.slot1_p0;
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kprobe_inst_p1 = bundle->quad1.slot1_p1;
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*kprobe_inst = kprobe_inst_p0 | (kprobe_inst_p1 << (64-46));
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break;
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case 2:
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*major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT);
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*kprobe_inst = bundle->quad1.slot2;
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break;
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}
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}
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static int valid_kprobe_addr(int template, int slot, unsigned long addr)
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{
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if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) {
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printk(KERN_WARNING "Attempting to insert unaligned kprobe at 0x%lx\n",
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addr);
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return -EINVAL;
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}
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return 0;
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}
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if (slot == 1 && bundle_encoding[template][1] == L) {
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lx_type_inst = 1;
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slot = 2;
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}
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int arch_prepare_kprobe(struct kprobe *p)
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{
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unsigned long addr = (unsigned long) p->addr;
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unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL);
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unsigned long kprobe_inst=0;
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unsigned int slot = addr & 0xf, template, major_opcode = 0;
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bundle_t *bundle = &p->ainsn.insn.bundle;
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switch (slot) {
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case 0:
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major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT);
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kprobe_inst = bundle->quad0.slot0;
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bundle->quad0.slot0 = BREAK_INST | (0x3f & kprobe_inst);
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break;
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case 1:
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major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT);
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kprobe_inst = (bundle->quad0.slot1_p0 |
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(bundle->quad1.slot1_p1 << (64-46)));
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bundle->quad0.slot1_p0 = BREAK_INST | (0x3f & kprobe_inst);
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bundle->quad1.slot1_p1 = (BREAK_INST >> (64-46));
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break;
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case 2:
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major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT);
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kprobe_inst = bundle->quad1.slot2;
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bundle->quad1.slot2 = BREAK_INST | (0x3f & kprobe_inst);
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break;
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}
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memcpy(&p->opcode.bundle, kprobe_addr, sizeof(bundle_t));
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memcpy(&p->ainsn.insn.bundle, kprobe_addr, sizeof(bundle_t));
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/*
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* Look for IP relative Branches, IP relative call or
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* IP relative predicate instructions
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*/
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if (bundle_encoding[template][slot] == B) {
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switch (major_opcode) {
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case INDIRECT_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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case IP_RELATIVE_PREDICT_OPCODE:
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case IP_RELATIVE_BRANCH_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
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break;
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case IP_RELATIVE_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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default:
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/* Do nothing */
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break;
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}
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} else if (lx_type_inst) {
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switch (major_opcode) {
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case LONG_CALL_OPCODE:
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p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
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p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
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break;
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default:
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/* Do nothing */
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break;
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}
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}
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template = bundle->quad0.template;
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if(valid_kprobe_addr(template, slot, addr))
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return -EINVAL;
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/* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
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if (slot == 1 && bundle_encoding[template][1] == L)
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slot++;
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/* Get kprobe_inst and major_opcode from the bundle */
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get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode);
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prepare_break_inst(template, slot, major_opcode, kprobe_inst, p);
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return 0;
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}
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@ -260,7 +311,7 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs)
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if (regs->cr_iip == bundle_addr) {
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regs->cr_iip = resume_addr;
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}
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}
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}
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turn_ss_off:
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/* Turn off Single Step bit */
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