Re: [PATCH v2 08/12] riscv: extend execmem_params for kprobes allocations

[Song Liu]

On Fri, Jun 16, 2023 at 1:52 AM Mike Rapoport <rppt@xxxxxxxxxx> wrote:
>
> From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx>
>
> RISC-V overrides kprobes::alloc_insn_range() to use the entire vmalloc area
> rather than limit the allocations to the modules area.
>
> Slightly reorder execmem_params initialization to support both 32 and 64
> bit variantsi and add definition of jit area to execmem_params to support
> generic kprobes::alloc_insn_page().
>
> Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

Acked-by: Song Liu <song@xxxxxxxxxx>


> ---
>  arch/riscv/kernel/module.c         | 16 +++++++++++++++-
>  arch/riscv/kernel/probes/kprobes.c | 10 ----------
>  2 files changed, 15 insertions(+), 11 deletions(-)
>
> diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
> index ee5e04cd3f21..cca6ed4e9340 100644
> --- a/arch/riscv/kernel/module.c
> +++ b/arch/riscv/kernel/module.c
> @@ -436,7 +436,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
>         return 0;
>  }
>
> -#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
> +#ifdef CONFIG_MMU
>  static struct execmem_params execmem_params = {
>         .modules = {
>                 .text = {
> @@ -444,12 +444,26 @@ static struct execmem_params execmem_params = {
>                         .alignment = 1,
>                 },
>         },
> +       .jit = {
> +               .text = {
> +                       .pgprot = PAGE_KERNEL_READ_EXEC,
> +                       .alignment = 1,
> +               },
> +       },
>  };
>
>  struct execmem_params __init *execmem_arch_params(void)
>  {
> +#ifdef CONFIG_64BIT
>         execmem_params.modules.text.start = MODULES_VADDR;
>         execmem_params.modules.text.end = MODULES_END;
> +#else
> +       execmem_params.modules.text.start = VMALLOC_START;
> +       execmem_params.modules.text.end = VMALLOC_END;
> +#endif
> +
> +       execmem_params.jit.text.start = VMALLOC_START;
> +       execmem_params.jit.text.end = VMALLOC_END;
>
>         return &execmem_params;
>  }
> diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
> index 2f08c14a933d..e64f2f3064eb 100644
> --- a/arch/riscv/kernel/probes/kprobes.c
> +++ b/arch/riscv/kernel/probes/kprobes.c
> @@ -104,16 +104,6 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
>         return 0;
>  }
>
> -#ifdef CONFIG_MMU
> -void *alloc_insn_page(void)
> -{
> -       return  __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END,
> -                                    GFP_KERNEL, PAGE_KERNEL_READ_EXEC,
> -                                    VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
> -                                    __builtin_return_address(0));
> -}
> -#endif
> -
>  /* install breakpoint in text */
>  void __kprobes arch_arm_kprobe(struct kprobe *p)
>  {
> --
> 2.35.1
>