From patchwork Fri Dec 20 20:04:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christina Schimpe X-Patchwork-Id: 103523 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 53CDA3858C51 for ; Fri, 20 Dec 2024 20:07:49 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 53CDA3858C51 Authentication-Results: sourceware.org; dkim=pass (2048-bit key, unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=UJj3Orrh X-Original-To: gdb-patches@sourceware.org Delivered-To: gdb-patches@sourceware.org Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) by sourceware.org (Postfix) with ESMTPS id BBF493858CD1 for ; Fri, 20 Dec 2024 20:05:43 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org BBF493858CD1 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=intel.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org BBF493858CD1 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=198.175.65.21 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1734725144; cv=none; b=QjxwvAfGdxjrC1EI73B91+x8q1um9o/ZDrcCAO9z+DAqdPRdvLxNatA5jr0z2o2ILMNDFifiokgsQAXJ5PKSndswQF1tY+ezWxMsiTjZwXaiilfB3qX2fC0BjqGDywYQOg4utZCf171emMXSvJMf2atfmhGDRqoxQIzjQ3B0nkM= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1734725144; c=relaxed/simple; bh=cFPWvaFyj/J/zQdyJf2gCj8oxqxo9q5gDVfDo3Q7CF8=; h=DKIM-Signature:From:To:Subject:Date:Message-Id:MIME-Version; b=ZEBx7mA2FFw3b2OOhUAD9C/KOHi9vINK6+1Y/JrzmIEU5eCZ8I8c75+o++vMxpz0m+FhgazSiRlh+fpZas7bMjyJjOs35etnMMBYxaavz32pLRaIuB5Iy1EiArGnYf2SNl0N2OVjApS4f/hDFRaLDRGivA7NY+B7AXP7JPjm/iQ= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BBF493858CD1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1734725144; x=1766261144; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=cFPWvaFyj/J/zQdyJf2gCj8oxqxo9q5gDVfDo3Q7CF8=; b=UJj3Orrhdu8gkdqAzbwG2NpxxxVMmNegOF7/AUHb14vMrRlEx6KYn6DQ Q89oV83sldA60S9sJe9W0eYojw6YkOE4NivD7nU+IhU5W/hJ0oReo97DH zaWmiKay2OnTIk2k0cjn1DFbAGMZHst3gnTdlOKiWvEZuvkUMe/GH09u4 wYhhCHCUvkPm+N0Ec21RH2yifDsxdLCgo3/u9DWINHzK4ssfj0Iae0BVo pHWHObvig9og/NU+yH4qpnwNTbfHdEw/+4wxDrzHUkRe8kaCQOcAL19Y4 WEkEN59m4ZFotDLu/M64Ywrucb4dIwKmrzEHpv0hLCG7vpVSoMzHud+NN A==; X-CSE-ConnectionGUID: 9PZdqWMMT5qtERtSApwQYg== X-CSE-MsgGUID: W/SdYgLNQ2Kp9Waxb/1eQA== X-IronPort-AV: E=McAfee;i="6700,10204,11292"; a="35174323" X-IronPort-AV: E=Sophos;i="6.12,251,1728975600"; d="scan'208";a="35174323" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Dec 2024 12:05:44 -0800 X-CSE-ConnectionGUID: tj4HzxYIQ2ak7tJUNfkEDw== X-CSE-MsgGUID: AYy4S2YESK2BpwdbXsyEhg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="121877561" Received: from gkldtt-dev-004.igk.intel.com (HELO localhost) ([10.123.221.202]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Dec 2024 12:05:42 -0800 From: "Schimpe, Christina" To: gdb-patches@sourceware.org Subject: [PATCH 02/12] gdbserver: Add optional runtime register set type. Date: Fri, 20 Dec 2024 20:04:51 +0000 Message-Id: <20241220200501.324191-3-christina.schimpe@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241220200501.324191-1-christina.schimpe@intel.com> References: <20241220200501.324191-1-christina.schimpe@intel.com> MIME-Version: 1.0 X-Spam-Status: No, score=-10.1 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces~patchwork=sourceware.org@sourceware.org Some register sets can be activated and deactivated by the OS during the runtime of a process. One example register is the Intel CET shadow stack pointer. This adds a new type of register set to handle such cases. We shouldn't deactivate these regsets and should not show a warning if we fail to read them. --- gdbserver/linux-low.cc | 40 ++++++++++++++++++++++++++++------------ gdbserver/linux-low.h | 7 ++++++- 2 files changed, 34 insertions(+), 13 deletions(-) diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc index 50ce2b44927..355b28d9fe4 100644 --- a/gdbserver/linux-low.cc +++ b/gdbserver/linux-low.cc @@ -5007,23 +5007,31 @@ regsets_fetch_inferior_registers (struct regsets_info *regsets_info, if (res < 0) { if (errno == EIO - || (errno == EINVAL && regset->type == OPTIONAL_REGS)) + || (errno == EINVAL + && (regset->type == OPTIONAL_REGS + || regset->type == OPTIONAL_RUNTIME_REGS))) { /* If we get EIO on a regset, or an EINVAL and the regset is - optional, do not try it again for this process mode. */ + optional, do not try it again for this process mode. + Even if the regset can be enabled at runtime it is safe + to deactivate the regset in case of EINVAL, as we know + the regset itself was the invalid argument of the ptrace + call. */ disable_regset (regsets_info, regset); } - else if (errno == ENODATA) + else if (errno == ENODATA + || (errno == ENODEV + && regset->type == OPTIONAL_RUNTIME_REGS) + || errno == ESRCH) { - /* ENODATA may be returned if the regset is currently - not "active". This can happen in normal operation, - so suppress the warning in this case. */ - } - else if (errno == ESRCH) - { - /* At this point, ESRCH should mean the process is - already gone, in which case we simply ignore attempts - to read its registers. */ + /* ENODATA or ENODEV may be returned if the regset is + currently not "active". For ENODEV we additionally check + if the register set is of type OPTIONAL_RUNTIME_REGS. + This can happen in normal operation, so suppress the + warning in this case. + ESRCH should mean the process is already gone at this + point, in which case we simply ignore attempts to read + its registers. */ } else { @@ -5111,6 +5119,14 @@ regsets_store_inferior_registers (struct regsets_info *regsets_info, optional, do not try it again for this process mode. */ disable_regset (regsets_info, regset); } + else if (errno == ENODEV + && regset->type == OPTIONAL_RUNTIME_REGS) + { + /* If we get ENODEV on a regset and the regset can be + enabled at runtime try it again for this process mode. + This can happen in normal operation, so suppress the + warning in this case. */ + } else if (errno == ESRCH) { /* At this point, ESRCH should mean the process is diff --git a/gdbserver/linux-low.h b/gdbserver/linux-low.h index 5be00b8c98c..da5aa26a993 100644 --- a/gdbserver/linux-low.h +++ b/gdbserver/linux-low.h @@ -42,7 +42,12 @@ enum regset_type { GENERAL_REGS, FP_REGS, EXTENDED_REGS, - OPTIONAL_REGS, /* Do not error if the regset cannot be accessed. */ + OPTIONAL_REGS, /* Do not error if the regset cannot be accessed. + Disable the regset instead. */ + OPTIONAL_RUNTIME_REGS, /* Some optional regsets can only be accessed + dependent on the execution flow. For such + access errors don't show a warning and don't + disable the regset. */ }; /* The arch's regsets array initializer must be terminated with a NULL