Commit 9522ef85 authored by Zheng Yejian's avatar Zheng Yejian
Browse files

livepatch/ppc64: Adjust instruction replace order for KLP_STACK_OPTIMIZE mode 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9R2TB



--------------------------------

Signed-off-by: default avatarZheng Yejian <zhengyejian1@huawei.com>
parent b980761b

arch/powerpc/kernel/livepatch_64.c

+5 −8
Original line number Diff line number Diff line
@@ -412,20 +412,17 @@ void arch_klp_unpatch_func(struct klp_func *func) 
	struct klp_func_node *func_node;

	struct klp_func *next_func;

	unsigned long pc;

	int i;

	int ret;



	func_node = func->func_node;

	pc = (unsigned long)func_node->old_func;

	list_del_rcu(&func->stack_node);

	if (list_empty(&func_node->func_stack)) {

		for (i = 0; i < LJMP_INSN_SIZE; i++) {

			ret = patch_instruction((struct ppc_inst *)((u32 *)pc + i),

						ppc_inst(func_node->arch_data.old_insns[i]));

		ret = klp_patch_text((u32 *)pc, func_node->arch_data.old_insns,

				     LJMP_INSN_SIZE);

		if (ret) {

				pr_err("restore instruction %d failed, ret=%d\n", i, ret);

				break;

			}

			pr_err("restore instruction failed, ret=%d\n", ret);

			return;

		}



		pr_debug("[%s %d] restore insns at 0x%lx\n", __func__, __LINE__, pc);

arch/powerpc/kernel/module_64.c

+20 −9
Original line number Diff line number Diff line
@@ -817,17 +817,18 @@ int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs) 
 * Patch jump stub to reference trampoline

 * without saved the old R2 and load the new R2.

 */

static int livepatch_create_bstub(struct ppc64_klp_bstub_entry *entry,

static int livepatch_create_bstub(void *pc,

				  unsigned long addr,

				  struct module *me)

{

	long reladdr;

	unsigned long my_r2;

	unsigned long stub_start, stub_end, stub_size;

	struct ppc64_klp_bstub_entry entry;



	/* Stub uses address relative to r2. */

	my_r2 = me ? me->arch.toc : kernel_toc_addr();

	reladdr = (unsigned long)entry - my_r2;

	reladdr = (unsigned long)pc - my_r2;

	if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {

		pr_err("%s: Address %p of jump stub out of range of %p.\n",

		       me ? me->name : "kernel",
@@ -839,15 +840,25 @@ static int livepatch_create_bstub(struct ppc64_klp_bstub_entry *entry, 
	stub_start = ppc_function_entry((void *)livepatch_branch_stub);

	stub_end = ppc_function_entry((void *)livepatch_branch_stub_end);

	stub_size = stub_end - stub_start;

	memcpy(entry->jump, (u32 *)stub_start, stub_size);

	memcpy(entry.jump, (u32 *)stub_start, stub_size);



	entry.jump[0] |= PPC_HA(reladdr);

	entry.jump[1] |= PPC_LO(reladdr);

	entry.magic = BRANCH_STUB_MAGIC;

	entry.trampoline = addr;



	entry->jump[0] |= PPC_HA(reladdr);

	entry->jump[1] |= PPC_LO(reladdr);

	entry->magic = BRANCH_STUB_MAGIC;

	entry->trampoline = addr;



	/* skip breakpoint at first */

	memcpy(pc + PPC64_INSN_SIZE, (void *)&entry + PPC64_INSN_SIZE,

	       sizeof(entry) - PPC64_INSN_SIZE);

	/*

	 * Avoid compile optimization, make sure that instructions

	 * except first breakpoint has been patched.

	 */

	barrier();

	memcpy(pc, (void *)&entry, PPC64_INSN_SIZE);

	pr_debug("Create livepatch branch stub 0x%px with reladdr 0x%lx r2 0x%lx to trampoline 0x%lx\n",

		(void *)entry, reladdr, my_r2, addr);

		pc, reladdr, my_r2, addr);



	return 1;

}
@@ -898,7 +909,7 @@ int livepatch_create_branch(unsigned long pc, 
#endif



	/* Create stub to trampoline */

	if (!livepatch_create_bstub((struct ppc64_klp_bstub_entry *)pc, trampoline, me))

	if (!livepatch_create_bstub((void *)pc, trampoline, me))

		return -EINVAL;



	return 0;