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Date:   Fri, 7 Jul 2023 08:06:19 +0200
From:   Thomas =?utf-8?Q?Wei=C3=9Fschuh?= <thomas@t-8ch.de>
To:     Palmer Dabbelt <palmer@rivosinc.com>
Cc:     mcgrof@kernel.org, rdunlap@infradead.org,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] module: Ignore RISC-V mapping symbols too
Message-ID: <3e905882-7f96-4fc0-aecf-6054ed00372e@t-8ch.de>
References: <20230707054007.32591-1-palmer@rivosinc.com>
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On 2023-07-06 22:40:01-0700, Palmer Dabbelt wrote:
> RISC-V has an extended form of mapping symbols that we use to encode
> the ISA when it changes in the middle of an ELF.  This trips up modpost
> as a build failure, I haven't yet verified it yet but I believe the
> kallsyms difference should result in stacks looking sane again.

> [..]

> diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
> index ef73ae7c8909..1e988e542c5d 100644
> --- a/kernel/module/kallsyms.c
> +++ b/kernel/module/kallsyms.c
> @@ -12,6 +12,12 @@
>  #include <linux/bsearch.h>
>  #include "internal.h"
>  
> +#ifdef CONFIG_RISCV
> +#define IS_RISCV 1
> +#else
> +#define IS_RISCV 0
> +#endif
> +
>  /* Lookup exported symbol in given range of kernel_symbols */
>  static const struct kernel_symbol *lookup_exported_symbol(const char *name,
>  							  const struct kernel_symbol *start,
> @@ -289,7 +295,7 @@ static const char *find_kallsyms_symbol(struct module *mod,
>  		 * and inserted at a whim.
>  		 */
>  		if (*kallsyms_symbol_name(kallsyms, i) == '\0' ||
> -		    is_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
> +		    is_mapping_symbol(kallsyms_symbol_name(kallsyms, i), IS_RISCV))

IS_BUILTIN(CONFIG_RISCV) or IS_ENABLED(CONFIG_RISCV) ?

>  			continue;
>  
>  		if (thisval <= addr && thisval > bestval) {

> [..]