From patchwork Tue Aug 22 09:30:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Helge Deller X-Patchwork-Id: 13360407 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7064FEE4993 for ; Tue, 22 Aug 2023 09:30:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234291AbjHVJa4 (ORCPT ); Tue, 22 Aug 2023 05:30:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234315AbjHVJa4 (ORCPT ); Tue, 22 Aug 2023 05:30:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E75B5CD1 for ; Tue, 22 Aug 2023 02:30:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7D34D61389 for ; Tue, 22 Aug 2023 09:30:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9F33C433C7; Tue, 22 Aug 2023 09:30:51 +0000 (UTC) Date: Tue, 22 Aug 2023 11:30:48 +0200 From: Helge Deller To: linux-parisc@vger.kernel.org Subject: [Fwd: [PATCH v2] procfs: Fix /proc/self/maps output for 32-bit kernel and compat tasks] Message-ID: MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org ----- Forwarded message from Helge Deller ----- Date: Tue, 22 Aug 2023 11:20:36 +0200 From: Helge Deller To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Andrei Vagin , Andrew Morton Subject: [PATCH v2] procfs: Fix /proc/self/maps output for 32-bit kernel and compat tasks Message-ID: On a 32-bit kernel addresses should be shown with 8 hex digits, e.g.: root@debian:~# cat /proc/self/maps 00010000-00019000 r-xp 00000000 08:05 787324 /usr/bin/cat 00019000-0001a000 rwxp 00009000 08:05 787324 /usr/bin/cat 0001a000-0003b000 rwxp 00000000 00:00 0 [heap] f7551000-f770d000 r-xp 00000000 08:05 794765 /usr/lib/hppa-linux-gnu/libc.so.6 f770d000-f770f000 r--p 001bc000 08:05 794765 /usr/lib/hppa-linux-gnu/libc.so.6 f770f000-f7714000 rwxp 001be000 08:05 794765 /usr/lib/hppa-linux-gnu/libc.so.6 f7d39000-f7d68000 r-xp 00000000 08:05 794759 /usr/lib/hppa-linux-gnu/ld.so.1 f7d68000-f7d69000 r--p 0002f000 08:05 794759 /usr/lib/hppa-linux-gnu/ld.so.1 f7d69000-f7d6d000 rwxp 00030000 08:05 794759 /usr/lib/hppa-linux-gnu/ld.so.1 f7ea9000-f7eaa000 r-xp 00000000 00:00 0 [vdso] f8565000-f8587000 rwxp 00000000 00:00 0 [stack] But since commmit 0e3dc0191431 ("procfs: add seq_put_hex_ll to speed up /proc/pid/maps") even on native 32-bit kernels the output looks like this: root@debian:~# cat /proc/self/maps 0000000010000-0000000019000 r-xp 00000000 000000008:000000005 787324 /usr/bin/cat 0000000019000-000000001a000 rwxp 000000009000 000000008:000000005 787324 /usr/bin/cat 000000001a000-000000003b000 rwxp 00000000 00:00 0 [heap] 00000000f73d1000-00000000f758d000 r-xp 00000000 000000008:000000005 794765 /usr/lib/hppa-linux-gnu/libc.so.6 00000000f758d000-00000000f758f000 r--p 000000001bc000 000000008:000000005 794765 /usr/lib/hppa-linux-gnu/libc.so.6 00000000f758f000-00000000f7594000 rwxp 000000001be000 000000008:000000005 794765 /usr/lib/hppa-linux-gnu/libc.so.6 00000000f7af9000-00000000f7b28000 r-xp 00000000 000000008:000000005 794759 /usr/lib/hppa-linux-gnu/ld.so.1 00000000f7b28000-00000000f7b29000 r--p 000000002f000 000000008:000000005 794759 /usr/lib/hppa-linux-gnu/ld.so.1 00000000f7b29000-00000000f7b2d000 rwxp 0000000030000 000000008:000000005 794759 /usr/lib/hppa-linux-gnu/ld.so.1 00000000f7e0c000-00000000f7e0d000 r-xp 00000000 00:00 0 [vdso] 00000000f9061000-00000000f9083000 rwxp 00000000 00:00 0 [stack] This patch brings back the old default 8-hex digit output for 32-bit kernels and compat tasks. Fixes: 0e3dc0191431 ("procfs: add seq_put_hex_ll to speed up /proc/pid/maps") Cc: Andrei Vagin Signed-off-by: Helge Deller --- v2: - Linux kernel test robot complained that is_compat_task() isn't known. Use in_compat_syscall() instead and check for 32-bit kernel with !IS_ENABLED(CONFIG_64BIT) --- ----- End forwarded message ----- diff --git a/fs/seq_file.c b/fs/seq_file.c index f5fdaf3b1572..52a0ea05cad2 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -759,8 +760,9 @@ void seq_put_hex_ll(struct seq_file *m, const char *delimiter, seq_puts(m, delimiter); } - /* If x is 0, the result of __builtin_clzll is undefined */ - if (v == 0) + /* If v is 0, the result of __builtin_clzll is undefined */ + /* Use provided width on 32-bit kernel and compat mode */ + if (v == 0 || !IS_ENABLED(CONFIG_64BIT) || in_compat_syscall()) len = 1; else len = (sizeof(v) * 8 - __builtin_clzll(v) + 3) / 4;