From f3eca956389316acd1a132fad1ad0b6f2ca78a61 Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Tue, 6 Jun 2017 14:29:39 +1000 Subject: [PATCH] powerpc/kprobes/optprobes: Use patch_instruction() So that we can implement STRICT_RWX, use patch_instruction() in optprobes. Signed-off-by: Balbir Singh Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/optprobes.c | 53 ++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 21 deletions(-) diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c index ec60ed0d4aad..6f8273f5e988 100644 --- a/arch/powerpc/kernel/optprobes.c +++ b/arch/powerpc/kernel/optprobes.c @@ -158,12 +158,13 @@ void arch_remove_optimized_kprobe(struct optimized_kprobe *op) void patch_imm32_load_insns(unsigned int val, kprobe_opcode_t *addr) { /* addis r4,0,(insn)@h */ - *addr++ = PPC_INST_ADDIS | ___PPC_RT(4) | - ((val >> 16) & 0xffff); + patch_instruction(addr, PPC_INST_ADDIS | ___PPC_RT(4) | + ((val >> 16) & 0xffff)); + addr++; /* ori r4,r4,(insn)@l */ - *addr = PPC_INST_ORI | ___PPC_RA(4) | ___PPC_RS(4) | - (val & 0xffff); + patch_instruction(addr, PPC_INST_ORI | ___PPC_RA(4) | + ___PPC_RS(4) | (val & 0xffff)); } /* @@ -173,24 +174,28 @@ void patch_imm32_load_insns(unsigned int val, kprobe_opcode_t *addr) void patch_imm64_load_insns(unsigned long val, kprobe_opcode_t *addr) { /* lis r3,(op)@highest */ - *addr++ = PPC_INST_ADDIS | ___PPC_RT(3) | - ((val >> 48) & 0xffff); + patch_instruction(addr, PPC_INST_ADDIS | ___PPC_RT(3) | + ((val >> 48) & 0xffff)); + addr++; /* ori r3,r3,(op)@higher */ - *addr++ = PPC_INST_ORI | ___PPC_RA(3) | ___PPC_RS(3) | - ((val >> 32) & 0xffff); + patch_instruction(addr, PPC_INST_ORI | ___PPC_RA(3) | + ___PPC_RS(3) | ((val >> 32) & 0xffff)); + addr++; /* rldicr r3,r3,32,31 */ - *addr++ = PPC_INST_RLDICR | ___PPC_RA(3) | ___PPC_RS(3) | - __PPC_SH64(32) | __PPC_ME64(31); + patch_instruction(addr, PPC_INST_RLDICR | ___PPC_RA(3) | + ___PPC_RS(3) | __PPC_SH64(32) | __PPC_ME64(31)); + addr++; /* oris r3,r3,(op)@h */ - *addr++ = PPC_INST_ORIS | ___PPC_RA(3) | ___PPC_RS(3) | - ((val >> 16) & 0xffff); + patch_instruction(addr, PPC_INST_ORIS | ___PPC_RA(3) | + ___PPC_RS(3) | ((val >> 16) & 0xffff)); + addr++; /* ori r3,r3,(op)@l */ - *addr = PPC_INST_ORI | ___PPC_RA(3) | ___PPC_RS(3) | - (val & 0xffff); + patch_instruction(addr, PPC_INST_ORI | ___PPC_RA(3) | + ___PPC_RS(3) | (val & 0xffff)); } int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) @@ -198,7 +203,8 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) kprobe_opcode_t *buff, branch_op_callback, branch_emulate_step; kprobe_opcode_t *op_callback_addr, *emulate_step_addr; long b_offset; - unsigned long nip; + unsigned long nip, size; + int rc, i; kprobe_ppc_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; @@ -231,8 +237,14 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) goto error; /* Setup template */ - memcpy(buff, optprobe_template_entry, - TMPL_END_IDX * sizeof(kprobe_opcode_t)); + /* We can optimize this via patch_instruction_window later */ + size = (TMPL_END_IDX * sizeof(kprobe_opcode_t)) / sizeof(int); + pr_devel("Copying template to %p, size %lu\n", buff, size); + for (i = 0; i < size; i++) { + rc = patch_instruction(buff + i, *(optprobe_template_entry + i)); + if (rc < 0) + goto error; + } /* * Fixup the template with instructions to: @@ -261,8 +273,8 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) if (!branch_op_callback || !branch_emulate_step) goto error; - buff[TMPL_CALL_HDLR_IDX] = branch_op_callback; - buff[TMPL_EMULATE_IDX] = branch_emulate_step; + patch_instruction(buff + TMPL_CALL_HDLR_IDX, branch_op_callback); + patch_instruction(buff + TMPL_EMULATE_IDX, branch_emulate_step); /* * 3. load instruction to be emulated into relevant register, and @@ -272,8 +284,7 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) /* * 4. branch back from trampoline */ - buff[TMPL_RET_IDX] = create_branch((unsigned int *)buff + TMPL_RET_IDX, - (unsigned long)nip, 0); + patch_branch(buff + TMPL_RET_IDX, (unsigned long)nip, 0); flush_icache_range((unsigned long)buff, (unsigned long)(&buff[TMPL_END_IDX])); -- 2.20.1