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From:   Song Liu <song@kernel.org>
Date:   Fri, 16 Jun 2023 11:56:09 -0700
Message-ID: <CAPhsuW7qEEbyEBUPETHxMj+Kusow5zTk3Q4cRNo0qV+quUsZNA@mail.gmail.com>
Subject: Re: [PATCH v2 05/12] modules, execmem: drop module_alloc
To:     Mike Rapoport <rppt@kernel.org>
Cc:     linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        "David S. Miller" <davem@davemloft.net>,
        Dinh Nguyen <dinguyen@kernel.org>,
        Heiko Carstens <hca@linux.ibm.com>,
        Helge Deller <deller@gmx.de>,
        Huacai Chen <chenhuacai@kernel.org>,
        Kent Overstreet <kent.overstreet@linux.dev>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Nadav Amit <nadav.amit@gmail.com>,
        "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Puranjay Mohan <puranjay12@gmail.com>,
        Rick Edgecombe <rick.p.edgecombe@intel.com>,
        Russell King <linux@armlinux.org.uk>,
        Steven Rostedt <rostedt@goodmis.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Will Deacon <will@kernel.org>, bpf@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org,
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        linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org,
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On Fri, Jun 16, 2023 at 1:51=E2=80=AFAM Mike Rapoport <rppt@kernel.org> wro=
te:
>
> From: "Mike Rapoport (IBM)" <rppt@kernel.org>
>
> Define default parameters for address range for code allocations using
> the current values in module_alloc() and make execmem_text_alloc() use
> these defaults when an architecure does not supply its specific
> parameters.
>
> With this, execmem_text_alloc() implements memory allocation in a way
> compatible with module_alloc() and can be used as a replacement for
> module_alloc().
>
> Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>

Acked-by: Song Liu <song@kernel.org>

> ---
>  include/linux/execmem.h      |  8 ++++++++
>  include/linux/moduleloader.h | 12 ------------
>  kernel/module/main.c         |  7 -------
>  mm/execmem.c                 | 12 ++++++++----
>  4 files changed, 16 insertions(+), 23 deletions(-)
>
> diff --git a/include/linux/execmem.h b/include/linux/execmem.h
> index 68b2bfc79993..b9a97fcdf3c5 100644
> --- a/include/linux/execmem.h
> +++ b/include/linux/execmem.h
> @@ -4,6 +4,14 @@
>
>  #include <linux/types.h>
>
> +#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && =
\
> +               !defined(CONFIG_KASAN_VMALLOC)
> +#include <linux/kasan.h>
> +#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
> +#else
> +#define MODULE_ALIGN PAGE_SIZE
> +#endif
> +
>  /**
>   * struct execmem_range - definition of a memory range suitable for code=
 and
>   *                       related data allocations
> diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
> index b3374342f7af..4321682fe849 100644
> --- a/include/linux/moduleloader.h
> +++ b/include/linux/moduleloader.h
> @@ -25,10 +25,6 @@ int module_frob_arch_sections(Elf_Ehdr *hdr,
>  /* Additional bytes needed by arch in front of individual sections */
>  unsigned int arch_mod_section_prepend(struct module *mod, unsigned int s=
ection);
>
> -/* Allocator used for allocating struct module, core sections and init
> -   sections.  Returns NULL on failure. */
> -void *module_alloc(unsigned long size);
> -
>  /* Determines if the section name is an init section (that is only used =
during
>   * module loading).
>   */
> @@ -113,12 +109,4 @@ void module_arch_cleanup(struct module *mod);
>  /* Any cleanup before freeing mod->module_init */
>  void module_arch_freeing_init(struct module *mod);
>
> -#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && =
\
> -               !defined(CONFIG_KASAN_VMALLOC)
> -#include <linux/kasan.h>
> -#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
> -#else
> -#define MODULE_ALIGN PAGE_SIZE
> -#endif
> -
>  #endif
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index 43810a3bdb81..b445c5ad863a 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -1600,13 +1600,6 @@ static void free_modinfo(struct module *mod)
>         }
>  }
>
> -void * __weak module_alloc(unsigned long size)
> -{
> -       return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> -                       GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERM=
S,
> -                       NUMA_NO_NODE, __builtin_return_address(0));
> -}
> -
>  bool __weak module_init_section(const char *name)
>  {
>         return strstarts(name, ".init");
> diff --git a/mm/execmem.c b/mm/execmem.c
> index 2fe36dcc7bdf..a67acd75ffef 100644
> --- a/mm/execmem.c
> +++ b/mm/execmem.c
> @@ -59,9 +59,6 @@ void *execmem_text_alloc(size_t size)
>         unsigned long fallback_end =3D execmem_params.modules.text.fallba=
ck_end;
>         bool kasan =3D execmem_params.modules.flags & EXECMEM_KASAN_SHADO=
W;
>
> -       if (!execmem_params.modules.text.start)
> -               return module_alloc(size);
> -
>         return execmem_alloc(size, start, end, align, pgprot,
>                              fallback_start, fallback_end, kasan);
>  }
> @@ -108,8 +105,15 @@ void __init execmem_init(void)
>  {
>         struct execmem_params *p =3D execmem_arch_params();
>
> -       if (!p)
> +       if (!p) {
> +               p =3D &execmem_params;
> +               p->modules.text.start =3D VMALLOC_START;
> +               p->modules.text.end =3D VMALLOC_END;
> +               p->modules.text.pgprot =3D PAGE_KERNEL_EXEC;
> +               p->modules.text.alignment =3D 1;
> +
>                 return;
> +       }
>
>         if (!execmem_validate_params(p))
>                 return;
> --
> 2.35.1
>