From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id AD34D3858C50; Thu, 3 Aug 2023 19:45:02 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org AD34D3858C50 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1691091902; bh=chVL2pUh4eGjrc4yzwlvgN0qKeVBB0ePY4dWKLwQ9JM=; h=From:To:Subject:Date:In-Reply-To:References:From; b=SIhEhQsaPy0Vbbkvzz8t/GMjsgMSh3SOmSo5h4BbzL49j43Cwa8IuM3jEVgiDCpto tMLfe46WUJOdi86zWEiIPHsDlLfUFu/sEWprzW6TP4rxWOICV27KfZ10t8hG+sab2E iV+Gp4AqL2Tqi54k0PJQ8w24vZXBDZONx7PmH8Ag= From: "wcohen at redhat dot com" To: systemtap@sourceware.org Subject: [Bug runtime/30716] On x86_64 get objtool warnings: call to __get_user_nocheck_1() with UACCESS enabled Date: Thu, 03 Aug 2023 19:45:02 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: systemtap X-Bugzilla-Component: runtime X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: wcohen at redhat dot com X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: systemtap at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_status Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://sourceware.org/bugzilla/show_bug.cgi?id=3D30716 William Cohen changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED --- Comment #1 from William Cohen --- objtool is reporting a call to a function with STAC (user-space access set) and the target of the call is not on the whitelist. Below is a link to the current linux 6.4.7 white list: https://elixir.bootlin.com/linux/v6.4.7/source/tools/objtool/check.c#L1120 The __get_user_nocheck_* function used by the x86_64 are not on that list. However, the implementations of the functions in arch/x86/lib/getuser.S do have surrounding ASM_STAC/ASM_CLAC instructions: https://elixir.bootlin.com/linux/v6.4.7/source/arch/x86/lib/getuser.S#L100 If these funcions were inlined, objtools would claim "recursive UACESS enabled" and "redundant UACCESS disable": https://elixir.bootlin.com/linux/v6.4.7/source/tools/objtool/check.c#L3737 The course of action is to have the systemtap code do the calls to these architecture specific functions without the additional STAC/CLAC from user_access_begin/user_access_end. One concern is how the user space accesses are implemented on other architectures and making sure that the fix works across all architectures. --=20 You are receiving this mail because: You are the assignee for the bug.=