Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.38 as permitted sender) client-ip=23.128.96.38;
MIME-Version: 1.0
References: <20231024010954.6768-1-quic_aiquny@quicinc.com>
In-Reply-To: <20231024010954.6768-1-quic_aiquny@quicinc.com>
From:   Ard Biesheuvel <ardb@kernel.org>
Date:   Tue, 24 Oct 2023 10:25:04 +0200
Message-ID: <CAMj1kXENRh6mvxc1QD67G7_t_H+WWhbyHFkfof5KOHT=MM2DJQ@mail.gmail.com>
Subject: Re: [PATCH v2] arm64: module: PLT allowed even !RANDOM_BASE
To:     Maria Yu <quic_aiquny@quicinc.com>
Cc:     catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kernel@quicinc.com, linux-arm-msm@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, 24 Oct 2023 at 03:10, Maria Yu <quic_aiquny@quicinc.com> wrote:
>
> Module PLT feature can be enabled even when RANDOM_BASE is disabled.
> Break BLT entry counts of relocation types will make module plt entry
> allocation fail and finally exec format error for even correct and plt
> allocation available modules.
>
> Signed-off-by: Maria Yu <quic_aiquny@quicinc.com>

Acked-by: Ard Biesheuvel <ardb@kernel.org>

> ---
>  arch/arm64/kernel/module-plts.c | 6 ------
>  1 file changed, 6 deletions(-)
>
> diff --git a/arch/arm64/kernel/module-plts.c b/arch/arm64/kernel/module-plts.c
> index bd69a4e7cd60..79200f21e123 100644
> --- a/arch/arm64/kernel/module-plts.c
> +++ b/arch/arm64/kernel/module-plts.c
> @@ -167,9 +167,6 @@ static unsigned int count_plts(Elf64_Sym *syms, Elf64_Rela *rela, int num,
>                 switch (ELF64_R_TYPE(rela[i].r_info)) {
>                 case R_AARCH64_JUMP26:
>                 case R_AARCH64_CALL26:
> -                       if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
> -                               break;
> -
>                         /*
>                          * We only have to consider branch targets that resolve
>                          * to symbols that are defined in a different section.
> @@ -269,9 +266,6 @@ static int partition_branch_plt_relas(Elf64_Sym *syms, Elf64_Rela *rela,
>  {
>         int i = 0, j = numrels - 1;
>
> -       if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
> -               return 0;
> -
>         while (i < j) {
>                 if (branch_rela_needs_plt(syms, &rela[i], dstidx))
>                         i++;
>
> base-commit: 05d3ef8bba77c1b5f98d941d8b2d4aeab8118ef1
> --
> 2.17.1
>