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Tue, 20 Sep 2022 19:24:24 +0000 Date: Tue, 20 Sep 2022 20:24:24 +0100 From: Al Viro To: Ren Zhijie Cc: ebiederm@xmission.com, keescook@chromium.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, tanghui20@huawei.com Subject: Re: [PATCH] exec: Force binary name when argv is empty Message-ID: References: <20220920120812.231417-1-renzhijie2@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220920120812.231417-1-renzhijie2@huawei.com> ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663701880; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=TPqwlRNwuUqV78TrpRLaS4sbUecgUF5r7GiXn2a7L1Q=; b=FlPA79NllrcIi56F+mTd1xT3VaorTjdW2fDMO82C/UlleMgqGX2u8FdwYYBjDa1qnQzYfx l9gySEDW0QlkcSIiufNw2g1cbEJQRlIB1kIS1EKqVY96Fhi8xkae4g+Ao4qkXEXp1Uw/z6 bAklGblGetE0g3SQnkRMe7Jg18g4wSE= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=hAMJs5X9; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk; spf=none (imf25.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663701880; a=rsa-sha256; cv=none; b=WaGPXayEGKzSjsFlNPChOKbmzTP4V9zErJkQ2OhksJI2XCwCFD0CPsEE1sI75G9/r0dXCK X0dnpA6qe7IQ6mgnXAj6bpZmTwVRBHWvNUZ8wGckse6kPyoRjHoUweI5K9QRse257QLP+7 /6LHCrKMAH3bl6ZgXDziRV3xjmqKaj4= X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 98018A00E0 X-Rspam-User: Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=hAMJs5X9; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk; spf=none (imf25.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk X-Stat-Signature: onybrnbdrmibr79womxc7pg87uby5hxn X-HE-Tag: 1663701880-162643 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Sep 20, 2022 at 08:08:12PM +0800, Ren Zhijie wrote: > From: Hui Tang > > First run './execv-main execv-child', there is empty in 'COMMAND' column > when run 'ps -u'. > > USER PID %CPU %MEM VSZ RSS TTY [...] TIME COMMAND > root 368 0.3 0.0 4388 764 ttyS0 0:00 ./execv-main > root 369 0.6 0.0 4520 812 ttyS0 0:00 > > The program 'execv-main' as follows: > > int main(int argc, char **argv) > { > char *execv_argv[] = {NULL}; > pid_t pid = fork(); > > if (pid == 0) { > execv(argv[1], execv_argv); > } else if (pid > 0) { > wait(NULL); > } > return 0; > } > > So replace empty string ("") added with the name of binary > when calling execve with a NULL argv. > > Fixes: dcd46d897adb ("exec: Force single empty string when argv is empty") I don't see the point, to be honest... You've passed BS argv to execve(), why would you expect anything pretty from ps(1)? IOW, where's the bug you are fixing?