linux-kernel - Re: [PATCH v9 2/3] cachestat: implement cachestat syscall

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <834254e6-a9c2-440c-9c67-fc5fa5ca43bc@app.fastmail.com>
Date:   Sun, 05 Feb 2023 10:55:38 +0100
From:   "Arnd Bergmann" <arnd@...db.de>
To:     "Nhat Pham" <nphamcs@...il.com>,
        "Andrew Morton" <akpm@...ux-foundation.org>
Cc:     "Johannes Weiner" <hannes@...xchg.org>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, bfoster@...hat.com,
        "Matthew Wilcox" <willy@...radead.org>, linux-api@...r.kernel.org,
        kernel-team@...a.com
Subject: Re: [PATCH v9 2/3] cachestat: implement cachestat syscall

On Fri, Feb 3, 2023, at 20:04, Nhat Pham wrote:

> +SYSCALL_DEFINE5(cachestat, unsigned int, fd, loff_t, off, size_t, len,
> +		struct cachestat __user *, cstat, unsigned int, flags)
> +{
> +	return ksys_cachestat(fd, off, len, cstat, flags);
> +}
> +
> +#ifdef CONFIG_COMPAT
> +COMPAT_SYSCALL_DEFINE6(cachestat, unsigned int, fd, 
> compat_arg_u64_dual(off),
> +		size_t, len, struct cachestat __user *, cstat, unsigned int, flags)
> +{
> +	return ksys_cachestat(fd, compat_arg_u64_glue(off), len, cstat, 
> flags);
> +}

This still looks wrong to me, as this compat definition does not match
the native variant on architectures that require 64-bit arguments to
be passed in aligned register pairs, such as arm, mips or ppc, but
not x86, s390 or riscv.

     Arnd