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powerpc/kprobes/optprobes: Use patch_instruction()

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So that we can implement STRICT_RWX, use patch_instruction() in
optprobes.

Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Balbir Singh 2017-06-06 14:29:39 +10:00 committed by Michael Ellerman
parent d07df82c43
commit f3eca95638
1 changed files with 32 additions and 21 deletions
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53
arch/powerpc/kernel/optprobes.c
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@ -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]));