diff options
Diffstat (limited to 'arch/powerpc/kernel/module_64.c')
-rw-r--r-- | arch/powerpc/kernel/module_64.c | 29 |
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); |