diff mbox series

[v2,8/9] riscv: module: Create module allocations without exec permissions

Message ID 20210401002900.470f3413@xhacker (mailing list archive)
State New, archived
Headers show
Series riscv: improve self-protection | expand

Commit Message

Jisheng Zhang March 31, 2021, 4:29 p.m. UTC
From: Jisheng Zhang <jszhang@kernel.org>

The core code manages the executable permissions of code regions of
modules explicitly, it is not necessary to create the module vmalloc
regions with RWX permissions. Create them with RW- permissions instead.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 arch/riscv/kernel/module.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Comments

Anup Patel April 2, 2021, 4:18 a.m. UTC | #1
On Wed, Mar 31, 2021 at 10:04 PM Jisheng Zhang
<jszhang3@mail.ustc.edu.cn> wrote:
>
> From: Jisheng Zhang <jszhang@kernel.org>
>
> The core code manages the executable permissions of code regions of
> modules explicitly, it is not necessary to create the module vmalloc
> regions with RWX permissions. Create them with RW- permissions instead.
>
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>

Looks good to me.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup

> ---
>  arch/riscv/kernel/module.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
> index 104fba889cf7..e89367bba7c9 100644
> --- a/arch/riscv/kernel/module.c
> +++ b/arch/riscv/kernel/module.c
> @@ -407,14 +407,20 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
>         return 0;
>  }
>
> -#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
> +#ifdef CONFIG_MMU
> +
> +#ifdef CONFIG_64BIT
>  #define VMALLOC_MODULE_START \
>          max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START)
> +#else
> +#define VMALLOC_MODULE_START   VMALLOC_START
> +#endif
> +
>  void *module_alloc(unsigned long size)
>  {
>         return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START,
>                                     VMALLOC_END, GFP_KERNEL,
> -                                   PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
> +                                   PAGE_KERNEL, 0, NUMA_NO_NODE,
>                                     __builtin_return_address(0));
>  }
>  #endif
> --
> 2.31.0
>
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
diff mbox series

Patch

diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 104fba889cf7..e89367bba7c9 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -407,14 +407,20 @@  int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
 	return 0;
 }
 
-#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
+#ifdef CONFIG_MMU
+
+#ifdef CONFIG_64BIT
 #define VMALLOC_MODULE_START \
 	 max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START)
+#else
+#define VMALLOC_MODULE_START	VMALLOC_START
+#endif
+
 void *module_alloc(unsigned long size)
 {
 	return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START,
 				    VMALLOC_END, GFP_KERNEL,
-				    PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
+				    PAGE_KERNEL, 0, NUMA_NO_NODE,
 				    __builtin_return_address(0));
 }
 #endif