linux-kernel - Re: [PATCH v3 4/5] module: Account for the build time module name mangling

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Message-ID: <0dff052c-3857-4af3-a809-30ba124c4686@suse.com>
Date: Wed, 14 May 2025 10:38:00 +0200
From: Petr Pavlu <petr.pavlu@...e.com>
To: Peter Zijlstra <peterz@...radead.org>
Cc: mcgrof@...nel.org, x86@...nel.org, hpa@...or.com,
 samitolvanen@...gle.com, da.gomez@...sung.com, masahiroy@...nel.org,
 nathan@...nel.org, nicolas@...sle.eu, linux-kernel@...r.kernel.org,
 linux-modules@...r.kernel.org, linux-kbuild@...r.kernel.org,
 hch@...radead.org, gregkh@...uxfoundation.org, roypat@...zon.co.uk,
 Sean Christopherson <seanjc@...gle.com>
Subject: Re: [PATCH v3 4/5] module: Account for the build time module name
 mangling

On 5/2/25 16:12, Peter Zijlstra wrote:
> Sean noted that scripts/Makefile.lib:name-fix-token rule will mangle
> the module name with s/-/_/g.
> 
> Since this happens late in the build, only the kernel needs to bother
> with this, the modpost tool still sees the original name.
> 
> Reported-by: Sean Christopherson <seanjc@...gle.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
> Tested-by: Sean Christopherson <seanjc@...gle.com>
> ---
>  kernel/module/main.c |   26 +++++++++++++++++++++++++-
>  1 file changed, 25 insertions(+), 1 deletion(-)
> 
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -170,6 +170,30 @@ static inline void add_taint_module(stru
>  }
>  
>  /*
> + * Like strncmp(), except s/-/_/g as per scripts/Makefile.lib:name-fix-token rule.
> + */
> +static int mod_strncmp(const char *str_a, const char *str_b, size_t n)
> +{
> +	for (int i = 0; i < n; i++) {

Nit: This could be 'size_t i' for consistency. I can adjust it when
picking up the series.

Reviewed-by: Petr Pavlu <petr.pavlu@...e.com>

-- Petr

> +		char a = str_a[i];
> +		char b = str_b[i];
> +		int d;
> +
> +		if (a == '-') a = '_';
> +		if (b == '-') b = '_';
> +
> +		d = a - b;
> +		if (d)
> +			return d;
> +
> +		if (!a)
> +			break;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> [...]