[PATCH v4 3/9] powerpc/kprobes/optprobes: Move over to patch_instruction
From: Balbir Singh <bsingharora@gmail.com>
Date: 2017-06-27 07:49:26
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
With text moving to read-only migrate optprobes to using the patch_instruction infrastructure. Without this optprobes will fail and complain. Signed-off-by: Balbir Singh <bsingharora@gmail.com> --- arch/powerpc/kernel/optprobes.c | 58 ++++++++++++++++++++++++++--------------- 1 file changed, 37 insertions(+), 21 deletions(-)
diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c
index ec60ed0..1c7326c 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((unsigned int *)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((unsigned int *)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((unsigned int *)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((unsigned int *)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((unsigned int *)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((unsigned int *)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((unsigned int *)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 +237,15 @@ 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((unsigned int *)buff + i, + *((unsigned int *)(optprobe_template_entry) + i)); + if (rc < 0) + goto error; + } /* * Fixup the template with instructions to:
@@ -261,8 +274,10 @@ 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((unsigned int *)buff + TMPL_CALL_HDLR_IDX, + branch_op_callback); + patch_instruction((unsigned int *)buff + TMPL_EMULATE_IDX, + branch_emulate_step); /* * 3. load instruction to be emulated into relevant register, and
@@ -272,8 +287,9 @@ 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_instruction((unsigned int *)buff + TMPL_RET_IDX, + create_branch((unsigned int *)buff + + TMPL_RET_IDX, (unsigned long)nip, 0)); flush_icache_range((unsigned long)buff, (unsigned long)(&buff[TMPL_END_IDX]));
--
2.9.4