1 files changed, 18 insertions, 11 deletions

diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index ff045644f13f..2ac78d207f77 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -502,9 +502,10 @@ static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
 static int restore_r2(const char *name, u32 *instruction, struct module *me)
 {
 	u32 *prev_insn = instruction - 1;
+	u32 insn_val = *instruction;
 
 	if (is_mprofile_ftrace_call(name))
-		return 1;
+		return 0;
 
 	/*
 	 * Make sure the branch isn't a sibling call.  Sibling calls aren't
@@ -512,19 +513,25 @@ static int restore_r2(const char *name, u32 *instruction, struct module *me)
 	 * restore afterwards.
 	 */
 	if (!instr_is_relative_link_branch(ppc_inst(*prev_insn)))
-		return 1;
+		return 0;
 
-	if (*instruction != PPC_RAW_NOP()) {
-		pr_err("%s: Expected nop after call, got %08x at %pS\n",
-			me->name, *instruction, instruction);
+	/*
+	 * For livepatch, the restore r2 instruction might have already been
+	 * written previously, if the referenced symbol is in a previously
+	 * unloaded module which is now being loaded again.  In that case, skip
+	 * the warning and the instruction write.
+	 */
+	if (insn_val == PPC_INST_LD_TOC)
 		return 0;
+
+	if (insn_val != PPC_RAW_NOP()) {
+		pr_err("%s: Expected nop after call, got %08x at %pS\n",
+			me->name, insn_val, instruction);
+		return -ENOEXEC;
 	}
 
 	/* ld r2,R2_STACK_OFFSET(r1) */
-	if (patch_instruction(instruction, ppc_inst(PPC_INST_LD_TOC)))
-		return 0;
-
-	return 1;
+	return patch_instruction(instruction, ppc_inst(PPC_INST_LD_TOC));
 }
 
 int apply_relocate_add(Elf64_Shdr *sechdrs,
@@ -648,8 +655,8 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 						strtab + sym->st_name);
 				if (!value)
 					return -ENOENT;
-				if (!restore_r2(strtab + sym->st_name,
-							(u32 *)location + 1, me))
+				if (restore_r2(strtab + sym->st_name,
+					       (u32 *)location + 1, me))
 					return -ENOEXEC;
 			} else
 				value += local_entry_offset(sym);