Commit e1627d21 authored by Zheng Yejian's avatar Zheng Yejian
Browse files

livepatch/x86: Ajust 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 e1241e75

arch/x86/kernel/livepatch.c

+17 −10
Original line number Diff line number Diff line
@@ -445,6 +445,21 @@ long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func) 
	return ret;

}



static void klp_patch_text(void *dst, const void *src, int len)

{

	if (len <= 1)

		return;

	/* skip breakpoint at first */

	text_poke(dst + 1, src + 1, len - 1);

	/*

	 * Avoid compile optimization, make sure that instructions

	 * except first breakpoint has been patched.

	 */

	barrier();

	/* update jmp opcode */

	text_poke(dst, src, 1);

}



int arch_klp_patch_func(struct klp_func *func)

{

	struct klp_func_node *func_node;
@@ -457,15 +472,7 @@ int arch_klp_patch_func(struct klp_func *func) 
	new_addr = (unsigned long)func->new_func;

	/* replace the text with the new text */

	new = (unsigned char *)klp_jmp_code(ip, new_addr);

#ifdef CONFIG_LIVEPATCH_STOP_MACHINE_CONSISTENCY

	/* update jmp offset */

	text_poke((void *)(ip + 1), new + 1, JMP_E9_INSN_SIZE - 1);

	/* update jmp opcode */

	text_poke((void *)ip, new, 1);

#else

	text_poke((void *)ip, new, JMP_E9_INSN_SIZE);

#endif



	klp_patch_text((void *)ip, (const void *)new, JMP_E9_INSN_SIZE);

	return 0;

}
@@ -490,6 +497,6 @@ void arch_klp_unpatch_func(struct klp_func *func) 
	}



	/* replace the text with the new text */

	text_poke((void *)ip, new, JMP_E9_INSN_SIZE);

	klp_patch_text((void *)ip, (const void *)new, JMP_E9_INSN_SIZE);

}

#endif