diff options
| -rw-r--r-- | arch/ia64/kernel/kprobes.c | 131 | ||||
| -rw-r--r-- | include/asm-ia64/kprobes.h | 17 |
2 files changed, 132 insertions, 16 deletions
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index 6683a44f419..20a250e2e9b 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -120,25 +120,75 @@ void arch_arm_kprobe(struct kprobe *p) unsigned long arm_addr = addr & ~0xFULL; unsigned long slot = addr & 0xf; unsigned long template; + unsigned long major_opcode = 0; + unsigned long lx_type_inst = 0; + unsigned long kprobe_inst = 0; bundle_t bundle; + p->ainsn.inst_flag = 0; + p->ainsn.target_br_reg = 0; + memcpy(&bundle, &p->ainsn.insn.bundle, sizeof(bundle_t)); + template = bundle.quad0.template; + if (slot == 1 && bundle_encoding[template][1] == L) { + lx_type_inst = 1; + slot = 2; + } + - template = bundle.quad0.template; - if (slot == 1 && bundle_encoding[template][1] == L) - slot = 2; switch (slot) { case 0: + major_opcode = (bundle.quad0.slot0 >> SLOT0_OPCODE_SHIFT); + kprobe_inst = bundle.quad0.slot0; bundle.quad0.slot0 = BREAK_INST; break; case 1: + major_opcode = (bundle.quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT); + kprobe_inst = (bundle.quad0.slot1_p0 | + (bundle.quad1.slot1_p1 << (64-46))); bundle.quad0.slot1_p0 = BREAK_INST; bundle.quad1.slot1_p1 = (BREAK_INST >> (64-46)); break; case 2: + major_opcode = (bundle.quad1.slot2 >> SLOT2_OPCODE_SHIFT); + kprobe_inst = bundle.quad1.slot2; bundle.quad1.slot2 = BREAK_INST; break; } + /* + * Look for IP relative Branches, IP relative call or + * IP relative predicate instructions + */ + if (bundle_encoding[template][slot] == B) { + switch (major_opcode) { + case INDIRECT_CALL_OPCODE: + p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; + p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); + break; + case IP_RELATIVE_PREDICT_OPCODE: + case IP_RELATIVE_BRANCH_OPCODE: + p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR; + break; + case IP_RELATIVE_CALL_OPCODE: + p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR; + p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; + p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); + break; + default: + /* Do nothing */ + break; + } + } else if (lx_type_inst) { + switch (major_opcode) { + case LONG_CALL_OPCODE: + p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG; + p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7); + break; + default: + /* Do nothing */ + break; + } + } /* Flush icache for the instruction at the emulated address */ flush_icache_range((unsigned long)&p->ainsn.insn.bundle, @@ -170,24 +220,75 @@ void arch_remove_kprobe(struct kprobe *p) * We are resuming execution after a single step fault, so the pt_regs * structure reflects the register state after we executed the instruction * located in the kprobe (p->ainsn.insn.bundle). We still need to adjust - * the ip to point back to the original stack address, and if we see that - * the slot has incremented back to zero, then we need to point to the next - * slot location. + * the ip to point back to the original stack address. To set the IP address + * to original stack address, handle the case where we need to fixup the + * relative IP address and/or fixup branch register. */ static void resume_execution(struct kprobe *p, struct pt_regs *regs) { - unsigned long bundle = (unsigned long)p->addr & ~0xFULL; + unsigned long bundle_addr = ((unsigned long) (&p->ainsn.insn.bundle)) & ~0xFULL; + unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL; + unsigned long template; + int slot = ((unsigned long)p->addr & 0xf); - /* - * TODO: Handle cases where kprobe was inserted on a branch instruction - */ + template = p->opcode.bundle.quad0.template; + + if (slot == 1 && bundle_encoding[template][1] == L) + slot = 2; + + if (p->ainsn.inst_flag) { - if (!ia64_psr(regs)->ri) - regs->cr_iip = bundle + 0x10; - else - regs->cr_iip = bundle; + if (p->ainsn.inst_flag & INST_FLAG_FIX_RELATIVE_IP_ADDR) { + /* Fix relative IP address */ + regs->cr_iip = (regs->cr_iip - bundle_addr) + resume_addr; + } + + if (p->ainsn.inst_flag & INST_FLAG_FIX_BRANCH_REG) { + /* + * Fix target branch register, software convention is + * to use either b0 or b6 or b7, so just checking + * only those registers + */ + switch (p->ainsn.target_br_reg) { + case 0: + if ((regs->b0 == bundle_addr) || + (regs->b0 == bundle_addr + 0x10)) { + regs->b0 = (regs->b0 - bundle_addr) + + resume_addr; + } + break; + case 6: + if ((regs->b6 == bundle_addr) || + (regs->b6 == bundle_addr + 0x10)) { + regs->b6 = (regs->b6 - bundle_addr) + + resume_addr; + } + break; + case 7: + if ((regs->b7 == bundle_addr) || + (regs->b7 == bundle_addr + 0x10)) { + regs->b7 = (regs->b7 - bundle_addr) + + resume_addr; + } + break; + } /* end switch */ + } + goto turn_ss_off; + } - ia64_psr(regs)->ss = 0; + if (slot == 2) { + if (regs->cr_iip == bundle_addr + 0x10) { + regs->cr_iip = resume_addr + 0x10; + } + } else { + if (regs->cr_iip == bundle_addr) { + regs->cr_iip = resume_addr; + } + } + +turn_ss_off: + /* Turn off Single Step bit */ + ia64_psr(regs)->ss = 0; } static void prepare_ss(struct kprobe *p, struct pt_regs *regs) diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h index fec3506e53f..d30af77a0b1 100644 --- a/include/asm-ia64/kprobes.h +++ b/include/asm-ia64/kprobes.h @@ -44,6 +44,17 @@ typedef struct _bundle { #define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)pentry +#define SLOT0_OPCODE_SHIFT (37) +#define SLOT1_p1_OPCODE_SHIFT (37 - (64-46)) +#define SLOT2_OPCODE_SHIFT (37) + +#define INDIRECT_CALL_OPCODE (1) +#define IP_RELATIVE_CALL_OPCODE (5) +#define IP_RELATIVE_BRANCH_OPCODE (4) +#define IP_RELATIVE_PREDICT_OPCODE (7) +#define LONG_BRANCH_OPCODE (0xC) +#define LONG_CALL_OPCODE (0xD) + typedef struct kprobe_opcode { bundle_t bundle; } kprobe_opcode_t; @@ -55,8 +66,12 @@ struct fnptr { /* Architecture specific copy of original instruction*/ struct arch_specific_insn { - /* copy of the original instruction */ + /* copy of the instruction to be emulated */ kprobe_opcode_t insn; + #define INST_FLAG_FIX_RELATIVE_IP_ADDR 1 + #define INST_FLAG_FIX_BRANCH_REG 2 + unsigned long inst_flag; + unsigned short target_br_reg; }; /* ia64 does not need this */ |