From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH v2 40/44] ubsan: Fix objtool UACCESS warns Date: Mon, 19 Sep 2022 12:00:19 +0200 Message-ID: <20220919101523.043382530@infradead.org> References: <20220919095939.761690562@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org E16336FB9B DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 7A6796FB82 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 21970416FD DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org CA2D441712 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=G+s8KeYPo3DKU8KAsFzI9EuTHpElgTPxlXfQAuxRCYE=; b=EFx7B8LZTc83Pl4WaazbOvooxh m5ZH43lt/bUlEN9jEiueLap+B4d87w5iLtoW12OfYwc57bGORzfANspx7UladbBmGSWc1xIqbuqIn FOYYsmRFy+hGwvwvJke8Fb32oGMOnwwKJRBjXTd62rAreByaRoia5cby7KftFCJ5X/Ml7ELcrwj5J eiKKDdHS7VBR9PkXXj1rPKGhThK0lQvF5JDGcSZD67Indcxu2z2DcH6Nt3bnOKQDsnf0QQZKS0PCq ltrSo2MfjxxanO8+19FzwsNyRAZqAIM7DEPtfJ6dxj7PDwKMiZ9L9kurxNJZpN7RIUHFgemSiXBCp JnN7XVag==; List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: peterz@infradead.org Cc: juri.lelli@redhat.com, rafael@kernel.org, catalin.marinas@arm.com, linus.walleij@linaro.org, bsegall@google.com, guoren@kernel.org, pavel@ucw.cz, agordeev@linux.ibm.com, linux-arch@vger.kernel.org, vincent.guittot@linaro.org, mpe@ellerman.id.au, chenhuacai@kernel.org, christophe.leroy@csgroup.eu, linux-acpi@vger.kernel.org, agross@kernel.org, geert@linux-m68k.org, linux-imx@nxp.com, vgupta@kernel.org, mattst88@gmail.com, mturquette@baylibre.com, sammy@sammy.net, pmladek@suse.com, linux-pm@vger.kernel.org, Sascha Hauer , linux-um@lists.infradead.org, npiggin@gmail.com, tglx@linutronix.de, linux-omap@vger.kernel.org, dietmar.eggemann@arm.com, andreyknvl@gmail.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, senozhatsky@chromium.org, svens@linux.ibm.com, jolsa@kernel.org, tj@kernel.org, Andrew Morton clang-14 allyesconfig gives: vmlinux.o: warning: objtool: emulator_cmpxchg_emulated+0x705: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: paging64_update_accessed_dirty_bits+0x39e: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: paging32_update_accessed_dirty_bits+0x390: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: ept_update_accessed_dirty_bits+0x43f: call to __ubsan_handle_load_invalid_value() with UACCESS enabled Add the required eflags save/restore and whitelist the thing. Signed-off-by: Peter Zijlstra (Intel) --- lib/ubsan.c | 5 ++++- tools/objtool/check.c | 1 + 2 files changed, 5 insertions(+), 1 deletion(-) --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -340,9 +340,10 @@ void __ubsan_handle_load_invalid_value(v { struct invalid_value_data *data = _data; char val_str[VALUE_LENGTH]; + unsigned long ua_flags = user_access_save(); if (suppress_report(&data->location)) - return; + goto out; ubsan_prologue(&data->location, "invalid-load"); @@ -352,6 +353,8 @@ void __ubsan_handle_load_invalid_value(v val_str, data->type->type_name); ubsan_epilogue(); +out: + user_access_restore(ua_flags); } EXPORT_SYMBOL(__ubsan_handle_load_invalid_value); --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1068,6 +1068,7 @@ static const char *uaccess_safe_builtin[ "__ubsan_handle_type_mismatch", "__ubsan_handle_type_mismatch_v1", "__ubsan_handle_shift_out_of_bounds", + "__ubsan_handle_load_invalid_value", /* misc */ "csum_partial_copy_generic", "copy_mc_fragile",