From: Al Viro <viro@zeniv.linux.org.uk>
To: Christoph Hellwig <hch@lst.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Arnd Bergmann <arnd@arndb.de>, Brian Gerst <brgerst@gmail.com>,
Luis Chamberlain <mcgrof@kernel.org>,
linux-arm-kernel@lists.infradead.org, x86@kernel.org,
linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org,
sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/4] exec: simplify the compat syscall handling
Date: Fri, 26 Mar 2021 16:12:23 +0000 [thread overview]
Message-ID: <YF4H58gozyNkoCeO@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <20210326143831.1550030-4-hch@lst.de>
On Fri, Mar 26, 2021 at 03:38:30PM +0100, Christoph Hellwig wrote:
> -static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr)
> +static const char __user *
> +get_user_arg_ptr(const char __user *const __user *argv, int nr)
> {
> - const char __user *native;
> -
> -#ifdef CONFIG_COMPAT
> - if (unlikely(argv.is_compat)) {
> + if (in_compat_syscall()) {
> + const compat_uptr_t __user *compat_argv =
> + compat_ptr((unsigned long)argv);
> compat_uptr_t compat;
>
> - if (get_user(compat, argv.ptr.compat + nr))
> + if (get_user(compat, compat_argv + nr))
> return ERR_PTR(-EFAULT);
> -
> return compat_ptr(compat);
> - }
> -#endif
> -
> - if (get_user(native, argv.ptr.native + nr))
> - return ERR_PTR(-EFAULT);
> + } else {
> + const char __user *native;
>
> - return native;
> + if (get_user(native, argv + nr))
> + return ERR_PTR(-EFAULT);
> + return native;
> + }
> }
Yecchhh.... So you have in_compat_syscall() called again and again, for
each argument in the list? I agree that current version is fucking ugly,
but I really hate that approach ;-/
next prev parent reply other threads:[~2021-03-26 16:13 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-26 14:38 cleanup compat exec handling Christoph Hellwig
2021-03-26 14:38 ` [PATCH 1/4] exec: remove do_execve Christoph Hellwig
2021-03-26 15:04 ` Arnd Bergmann
2021-03-26 14:38 ` [PATCH 2/4] exec: remove compat_do_execve Christoph Hellwig
2021-03-26 15:42 ` Andreas Schwab
2021-03-27 19:56 ` Sergei Shtylyov
2021-03-26 14:38 ` [PATCH 3/4] exec: simplify the compat syscall handling Christoph Hellwig
2021-03-26 15:02 ` Arnd Bergmann
2021-03-26 16:12 ` Al Viro [this message]
2021-03-26 16:44 ` David Laight
2021-03-26 21:22 ` Eric W. Biederman
2021-03-26 14:38 ` [PATCH 4/4] exec: move the call to getname_flags into do_execveat Christoph Hellwig
2021-03-26 15:12 ` Arnd Bergmann
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