From patchwork Fri Apr 17 21:09:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 11496147 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B8B911392 for ; Fri, 17 Apr 2020 21:13:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A6757214D8 for ; Fri, 17 Apr 2020 21:13:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727971AbgDQVNA (ORCPT ); Fri, 17 Apr 2020 17:13:00 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:46920 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726129AbgDQVNA (ORCPT ); Fri, 17 Apr 2020 17:13:00 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out03.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jPYIE-00064z-Sv; Fri, 17 Apr 2020 15:12:58 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1jPYID-0007o4-Fc; Fri, 17 Apr 2020 15:12:58 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Christoph Hellwig Cc: Andrew Morton , Alexander Viro , Jeremy Kerr , Arnd Bergmann , linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org References: <20200414070142.288696-1-hch@lst.de> <20200414070142.288696-3-hch@lst.de> <87pnc5akhk.fsf@x220.int.ebiederm.org> Date: Fri, 17 Apr 2020 16:09:56 -0500 In-Reply-To: <87pnc5akhk.fsf@x220.int.ebiederm.org> (Eric W. Biederman's message of "Fri, 17 Apr 2020 16:08:23 -0500") Message-ID: <87eeslakez.fsf_-_@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1jPYID-0007o4-Fc;;;mid=<87eeslakez.fsf_-_@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+se8KiNrzXF7RzWVDO08sNWSsUt9u0V5I= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa08.xmission.com X-Spam-Level: *** X-Spam-Status: No, score=3.5 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,TR_Symld_Words,T_TooManySym_01,T_TooManySym_02, XMNoVowels,XMSubLong autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4301] * 0.7 XMSubLong Long Subject * 1.5 TR_Symld_Words too many words that have symbols inside * 1.5 XMNoVowels Alpha-numberic number with no vowels * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa08 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject X-Spam-DCC: XMission; sa08 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ***;Christoph Hellwig X-Spam-Relay-Country: X-Spam-Timing: total 489 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 14 (2.9%), b_tie_ro: 12 (2.5%), parse: 1.15 (0.2%), extract_message_metadata: 12 (2.5%), get_uri_detail_list: 1.69 (0.3%), tests_pri_-1000: 12 (2.5%), tests_pri_-950: 1.40 (0.3%), tests_pri_-900: 1.14 (0.2%), tests_pri_-90: 239 (48.9%), check_bayes: 237 (48.4%), b_tokenize: 6 (1.2%), b_tok_get_all: 166 (33.9%), b_comp_prob: 3.5 (0.7%), b_tok_touch_all: 56 (11.5%), b_finish: 1.37 (0.3%), tests_pri_0: 195 (39.9%), check_dkim_signature: 0.51 (0.1%), check_dkim_adsp: 2.7 (0.6%), poll_dns_idle: 1.02 (0.2%), tests_pri_10: 2.1 (0.4%), tests_pri_500: 7 (1.4%), rewrite_mail: 0.00 (0.0%) Subject: [PATCH 2/2] signal: Remove the set_fs in binfmt_elf.c:fill_siginfo_note X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The code in binfmt_elf.c is differnt from the rest of the code that processes siginfo, as it sends siginfo from a kernel buffer to a file rather than from kernel memory to userspace buffers. To remove it's use of set_fs the code needs some different siginfo helpers. Add the helper copy_siginfo_to_external to copy from the kernel's internal siginfo layout to a buffer in the siginfo layout that userspace expects. Modify fill_siginfo_note to use copy_siginfo_to_external instead of set_fs and copy_siginfo_to_user. Update compat_binfmt_elf.c to use the previously added copy_siginfo_to_external32 to handle the compat case. Signed-off-by: "Eric W. Biederman" --- fs/binfmt_elf.c | 5 +---- fs/compat_binfmt_elf.c | 2 +- include/linux/signal.h | 7 +++++++ 3 files changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 13f25e241ac4..a1f57e20c3cf 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1556,10 +1556,7 @@ static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, const kernel_siginfo_t *siginfo) { - mm_segment_t old_fs = get_fs(); - set_fs(KERNEL_DS); - copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo); - set_fs(old_fs); + copy_siginfo_to_external(csigdata, siginfo); fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); } diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index aaad4ca1217e..fa0e24e1b726 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -39,7 +39,7 @@ */ #define user_long_t compat_long_t #define user_siginfo_t compat_siginfo_t -#define copy_siginfo_to_user copy_siginfo_to_user32 +#define copy_siginfo_to_external copy_siginfo_to_external32 /* * The machine-dependent core note format types are defined in elfcore-compat.h, diff --git a/include/linux/signal.h b/include/linux/signal.h index 05bacd2ab135..c1796321cadb 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -24,6 +24,13 @@ static inline void clear_siginfo(kernel_siginfo_t *info) #define SI_EXPANSION_SIZE (sizeof(struct siginfo) - sizeof(struct kernel_siginfo)) +static inline void copy_siginfo_to_external(siginfo_t *to, + const kernel_siginfo_t *from) +{ + memcpy(to, from, sizeof(*from)); + memset(((char *)to) + sizeof(struct kernel_siginfo), 0, SI_EXPANSION_SIZE); +} + int copy_siginfo_to_user(siginfo_t __user *to, const kernel_siginfo_t *from); int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from);