linux-kernel - Re: [PATCH v5 08/13] module: Move kmemleak support to a separate file

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Message-ID: <2bee9eb2-d59f-a5cd-d89a-b818d94b74af@csgroup.eu>
Date:   Thu, 10 Feb 2022 13:07:22 +0000
From:   Christophe Leroy <christophe.leroy@...roup.eu>
To:     "20220209170358.3266629-1-atomlin@...hat.com" 
        <20220209170358.3266629-1-atomlin@...hat.com>,
        "mcgrof@...nel.org" <mcgrof@...nel.org>,
        Aaron Tomlin <atomlin@...hat.com>
CC:     "cl@...ux.com" <cl@...ux.com>,
        "pmladek@...e.com" <pmladek@...e.com>,
        "mbenes@...e.cz" <mbenes@...e.cz>,
        "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
        "jeyu@...nel.org" <jeyu@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-modules@...r.kernel.org" <linux-modules@...r.kernel.org>,
        "live-patching@...r.kernel.org" <live-patching@...r.kernel.org>,
        "atomlin@...mlin.com" <atomlin@...mlin.com>,
        "ghalat@...hat.com" <ghalat@...hat.com>,
        "allen.lkml@...il.com" <allen.lkml@...il.com>,
        "void@...ifault.com" <void@...ifault.com>,
        "joe@...ches.com" <joe@...ches.com>,
        "msuchanek@...e.de" <msuchanek@...e.de>,
        "oleksandr@...alenko.name" <oleksandr@...alenko.name>
Subject: Re: [PATCH v5 08/13] module: Move kmemleak support to a separate file



Le 09/02/2022 à 18:08, Aaron Tomlin a écrit :
> No functional change.
> 
> This patch migrates kmemleak code out of core module
> code into kernel/module/debug_kmemleak.c
> 
> Signed-off-by: Aaron Tomlin <atomlin@...hat.com>
> ---
>   kernel/module/Makefile         |  1 +
>   kernel/module/debug_kmemleak.c | 30 ++++++++++++++++++++++++++++++
>   kernel/module/internal.h       |  7 +++++++
>   kernel/module/main.c           | 27 ---------------------------
>   4 files changed, 38 insertions(+), 27 deletions(-)
>   create mode 100644 kernel/module/debug_kmemleak.c
> 
> diff --git a/kernel/module/Makefile b/kernel/module/Makefile
> index 8f2857d9ba1e..62c9fc91d411 100644
> --- a/kernel/module/Makefile
> +++ b/kernel/module/Makefile
> @@ -11,4 +11,5 @@ ifdef CONFIG_MODULES
>   obj-$(CONFIG_LIVEPATCH) += livepatch.o
>   obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
>   obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
> +obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
>   endif
> diff --git a/kernel/module/debug_kmemleak.c b/kernel/module/debug_kmemleak.c
> new file mode 100644
> index 000000000000..e896c2268011
> --- /dev/null
> +++ b/kernel/module/debug_kmemleak.c
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Module kmemleak support
> + *
> + * Copyright (C) 2009 Catalin Marinas
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kmemleak.h>
> +#include "internal.h"
> +
> +void kmemleak_load_module(const struct module *mod,
> +				 const struct load_info *info)

CHECK: Alignment should match open parenthesis
#48: FILE: kernel/module/debug_kmemleak.c:13:
+void kmemleak_load_module(const struct module *mod,
+				 const struct load_info *info)



> +{
> +	unsigned int i;
> +
> +	/* only scan the sections containing data */
> +	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
> +
> +	for (i = 1; i < info->hdr->e_shnum; i++) {
> +		/* Scan all writable sections that's not executable */
> +		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
> +		    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
> +		    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
> +			continue;
> +
> +		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
> +				   info->sechdrs[i].sh_size, GFP_KERNEL);
> +	}
> +}
> diff --git a/kernel/module/internal.h b/kernel/module/internal.h
> index 6d5891cc8421..33d7befd0602 100644
> --- a/kernel/module/internal.h
> +++ b/kernel/module/internal.h
> @@ -171,3 +171,10 @@ static inline int module_sig_check(struct load_info *info, int flags)
>   	return 0;
>   }
>   #endif /* !CONFIG_MODULE_SIG */
> +
> +#ifdef CONFIG_DEBUG_KMEMLEAK
> +void kmemleak_load_module(const struct module *mod, const struct load_info *info);
> +#else /* !CONFIG_DEBUG_KMEMLEAK */
> +static inline void __maybe_unused kmemleak_load_module(const struct module *mod,
> +						       const struct load_info *info) { }

Remove __maybe_unused, not needed for a 'static inline' in the .h


> +#endif /* CONFIG_DEBUG_KMEMLEAK */
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index 403f2aacb3f6..c9931479e2eb 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -2515,33 +2515,6 @@ bool __weak module_exit_section(const char *name)
>   	return strstarts(name, ".exit");
>   }
>   
> -#ifdef CONFIG_DEBUG_KMEMLEAK
> -static void kmemleak_load_module(const struct module *mod,
> -				 const struct load_info *info)
> -{
> -	unsigned int i;
> -
> -	/* only scan the sections containing data */
> -	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
> -
> -	for (i = 1; i < info->hdr->e_shnum; i++) {
> -		/* Scan all writable sections that's not executable */
> -		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
> -		    !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
> -		    (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
> -			continue;
> -
> -		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
> -				   info->sechdrs[i].sh_size, GFP_KERNEL);
> -	}
> -}
> -#else
> -static inline void kmemleak_load_module(const struct module *mod,
> -					const struct load_info *info)
> -{
> -}
> -#endif
> -
>   static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
>   {
>   #if defined(CONFIG_64BIT)