Re: [PATCH] arm64/kernel: rename module_emit_adrp_veneer->module_emit_veneer_for_adrp

[Ard Biesheuvel]

On 24 April 2018 at 17:13, Kim Phillips <kim.phillips@xxxxxxx> wrote:
> Commit a257e02579e ("arm64/kernel: don't ban ADRP to work around
> Cortex-A53 erratum #843419") introduced a function whose name ends with
> "_veneer".
>
> This clashes with commit bd8b22d2888e ("Kbuild: kallsyms: ignore veneers
> emitted by the ARM linker"), which removes symbols ending in "_veneer"
> from kallsyms.
>
> The problem was manifested as 'perf test -vvvvv vmlinux' failed,
> correctly claiming the symbol 'module_emit_adrp_veneer' was present in
> vmlinux, but not in kallsyms.
>
> ...
>     ERR : 0xffff00000809aa58: module_emit_adrp_veneer not on kallsyms
> ...
>     test child finished with -1
>     ---- end ----
>     vmlinux symtab matches kallsyms: FAILED!
>
> Fix the problem by renaming module_emit_veneer_for_adrp,
> module_emit_veneer_for_adrp.

That sentence didn't come out right

>  Now the test passes.
>
> Fixes: a257e02579e ("arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419")
> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Michal Marek <mmarek@xxxxxxx>
> Signed-off-by: Kim Phillips <kim.phillips@xxxxxxx>

Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>

> ---
>  arch/arm64/include/asm/module.h | 2 +-
>  arch/arm64/kernel/module-plts.c | 2 +-
>  arch/arm64/kernel/module.c      | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/include/asm/module.h b/arch/arm64/include/asm/module.h
> index b6dbbe3123a9..97d0ef12e2ff 100644
> --- a/arch/arm64/include/asm/module.h
> +++ b/arch/arm64/include/asm/module.h
> @@ -39,7 +39,7 @@ struct mod_arch_specific {
>  u64 module_emit_plt_entry(struct module *mod, void *loc, const Elf64_Rela *rela,
>                           Elf64_Sym *sym);
>
> -u64 module_emit_adrp_veneer(struct module *mod, void *loc, u64 val);
> +u64 module_emit_veneer_for_adrp(struct module *mod, void *loc, u64 val);
>
>  #ifdef CONFIG_RANDOMIZE_BASE
>  extern u64 module_alloc_base;
> diff --git a/arch/arm64/kernel/module-plts.c b/arch/arm64/kernel/module-plts.c
> index fa3637284a3d..f0690c2ca3e0 100644
> --- a/arch/arm64/kernel/module-plts.c
> +++ b/arch/arm64/kernel/module-plts.c
> @@ -43,7 +43,7 @@ u64 module_emit_plt_entry(struct module *mod, void *loc, const Elf64_Rela *rela,
>  }
>
>  #ifdef CONFIG_ARM64_ERRATUM_843419
> -u64 module_emit_adrp_veneer(struct module *mod, void *loc, u64 val)
> +u64 module_emit_veneer_for_adrp(struct module *mod, void *loc, u64 val)
>  {
>         struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core :
>                                                           &mod->arch.init;
> diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
> index 719fde8dcc19..155fd91e78f4 100644
> --- a/arch/arm64/kernel/module.c
> +++ b/arch/arm64/kernel/module.c
> @@ -215,7 +215,7 @@ static int reloc_insn_adrp(struct module *mod, __le32 *place, u64 val)
>                 insn &= ~BIT(31);
>         } else {
>                 /* out of range for ADR -> emit a veneer */
> -               val = module_emit_adrp_veneer(mod, place, val & ~0xfff);
> +               val = module_emit_veneer_for_adrp(mod, place, val & ~0xfff);
>                 if (!val)
>                         return -ENOEXEC;
>                 insn = aarch64_insn_gen_branch_imm((u64)place, val,
> --
> 2.17.0
>