linux-kernel - Re: [PATCH v2 2/8] execmem: introduce execmem_alloc

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Message-ID: <784081fa-0fee-4df6-b8d5-6435eead877f@kernel.org>
Date: Fri, 11 Jul 2025 16:29:48 +0200
From: Daniel Gomez <da.gomez@...nel.org>
To: Mike Rapoport <rppt@...nel.org>, Andrew Morton <akpm@...ux-foundation.org>
Cc: Andy Lutomirski <luto@...nel.org>, Borislav Petkov <bp@...en8.de>,
 Christophe Leroy <christophe.leroy@...roup.eu>,
 Daniel Gomez <da.gomez@...sung.com>,
 Dave Hansen <dave.hansen@...ux.intel.com>, Ingo Molnar <mingo@...hat.com>,
 "Liam R. Howlett" <Liam.Howlett@...cle.com>,
 Luis Chamberlain <mcgrof@...nel.org>, Mark Rutland <mark.rutland@....com>,
 Masami Hiramatsu <mhiramat@...nel.org>, "H. Peter Anvin" <hpa@...or.com>,
 Peter Zijlstra <peterz@...radead.org>, Petr Pavlu <petr.pavlu@...e.com>,
 Sami Tolvanen <samitolvanen@...gle.com>, Steven Rostedt
 <rostedt@...dmis.org>, Thomas Gleixner <tglx@...utronix.de>,
 Yann Ylavic <ylavic.dev@...il.com>, linux-kernel@...r.kernel.org,
 linux-mm@...ck.org, linux-modules@...r.kernel.org,
 linux-trace-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH v2 2/8] execmem: introduce execmem_alloc_rw()

On 09/07/2025 15.49, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@...nel.org>
> 
> Some callers of execmem_alloc() require the memory to be temporarily
> writable even when it is allocated from ROX cache. These callers use
> execemem_make_temp_rw() right after the call to execmem_alloc().
> 
> Wrap this sequence in execmem_alloc_rw() API.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@...nel.org>

Reviewed-by: Daniel Gomez <da.gomez@...sung.com>

> ---
> diff --git a/mm/execmem.c b/mm/execmem.c
> index 0712ebb4eb77..6b040fbc5f4f 100644
> --- a/mm/execmem.c
> +++ b/mm/execmem.c

{...}

> @@ -387,6 +397,21 @@ void *execmem_alloc(enum execmem_type type, size_t size)
>  	return kasan_reset_tag(p);
>  }
>  
> +void *execmem_alloc_rw(enum execmem_type type, size_t size)
> +{
> +	void *p __free(execmem) = execmem_alloc(type, size);
> +	int err;
> +
> +	if (!p)
> +		return NULL;
> +
> +	err = execmem_force_rw(p, size);
> +	if (err)
> +		return NULL;

You don't need to save the error here. That, allows err declaration to be
dropped.