[PATCH] Kprobes ia64 cleanup
A cleanup of the ia64 kprobes implementation such that all of the bundle manipulation logic is concentrated in arch_prepare_kprobe(). With the current design for kprobes, the arch specific code only has a chance to return failure inside the arch_prepare_kprobe() function. This patch moves all of the work that was happening in arch_copy_kprobe() and most of the work that was happening in arch_arm_kprobe() into arch_prepare_kprobe(). By doing this we can add further robustness checks in arch_arm_kprobe() and refuse to insert kprobes that will cause problems. Signed-off-by: Rusty Lynch <Rusty.lynch@intel.com> 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>
This commit is contained in:
Rusty Lynch
Linus Torvalds
parent
cd2675bf65
commit
8bc76772ad
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@ -84,121 +84,97 @@ static enum instruction_type bundle_encoding[32][3] = {
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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 bundle_addr = addr & ~0xFULL;
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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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bundle_t bundle;
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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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/*
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* TODO: Verify that a probe is not being inserted
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* in sensitive regions of code
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* TODO: Verify that the memory holding the probe is rwx
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* TODO: verify this is a kernel address
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*/
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memcpy(&bundle, (unsigned long *)bundle_addr, sizeof(bundle_t));
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template = bundle.quad0.template;
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if (((bundle_encoding[template][1] == L) && slot > 1) || (slot > 2)) {
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printk(KERN_WARNING "Attempting to insert unaligned kprobe at 0x%lx\n", addr);
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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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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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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;
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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;
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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;
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break;
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}
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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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return 0;
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}
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void arch_copy_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 bundle_addr = addr & ~0xFULL;
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memcpy(&p->ainsn.insn.bundle, (unsigned long *)bundle_addr,
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sizeof(bundle_t));
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memcpy(&p->opcode.bundle, &p->ainsn.insn.bundle, sizeof(bundle_t));
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}
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void arch_arm_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 arm_addr = 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;
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p->ainsn.inst_flag = 0;
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p->ainsn.target_br_reg = 0;
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memcpy(&bundle, &p->ainsn.insn.bundle, sizeof(bundle_t));
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template = bundle.quad0.template;
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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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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;
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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;
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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;
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break;
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}
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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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/* Flush icache for the instruction at the emulated address */
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flush_icache_range((unsigned long)&p->ainsn.insn.bundle,
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(unsigned long)&p->ainsn.insn.bundle +
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sizeof(bundle_t));
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/*
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* Patch the original instruction with the probe instruction
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* and flush the instruction cache
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*/
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memcpy((char *) arm_addr, (char *) &bundle, sizeof(bundle_t));
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memcpy((char *)arm_addr, &p->ainsn.insn.bundle, sizeof(bundle_t));
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flush_icache_range(arm_addr, arm_addr + sizeof(bundle_t));
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}
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@ -226,7 +202,7 @@ void arch_remove_kprobe(struct kprobe *p)
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*/
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static void resume_execution(struct kprobe *p, struct pt_regs *regs)
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{
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unsigned long bundle_addr = ((unsigned long) (&p->ainsn.insn.bundle)) & ~0xFULL;
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unsigned long bundle_addr = ((unsigned long) (&p->opcode.bundle)) & ~0xFULL;
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unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL;
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unsigned long template;
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int slot = ((unsigned long)p->addr & 0xf);
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@ -293,7 +269,7 @@ turn_ss_off:
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static void prepare_ss(struct kprobe *p, struct pt_regs *regs)
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{
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unsigned long bundle_addr = (unsigned long) &p->ainsn.insn.bundle;
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unsigned long bundle_addr = (unsigned long) &p->opcode.bundle;
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unsigned long slot = (unsigned long)p->addr & 0xf;
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/* Update instruction pointer (IIP) and slot number (IPSR.ri) */
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@ -30,6 +30,8 @@
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#define BREAK_INST (long)(__IA64_BREAK_KPROBE << 6)
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struct kprobe;
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typedef struct _bundle {
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struct {
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unsigned long long template : 5;
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@ -79,6 +81,11 @@ static inline void jprobe_return(void)
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{
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}
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/* ia64 does not need this */
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static inline void arch_copy_kprobe(struct kprobe *p)
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{
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}
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#ifdef CONFIG_KPROBES
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extern int kprobe_exceptions_notify(struct notifier_block *self,
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unsigned long val, void *data);
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