From patchwork Fri Jul 13 16:11:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Christophe Lyon X-Patchwork-Id: 141921 Delivered-To: patch@linaro.org Received: by 2002:a2e:9754:0:0:0:0:0 with SMTP id f20-v6csp989240ljj; Fri, 13 Jul 2018 09:14:21 -0700 (PDT) X-Google-Smtp-Source: AAOMgpf0Yz90OyJncz1r0svY6wQbixb/35BVOGN6zyct+lgEAxECUnl4OjSFQRDfPBbRcvXNCLsp X-Received: by 2002:a62:3f99:: with SMTP id z25-v6mr7809124pfj.250.1531498461872; Fri, 13 Jul 2018 09:14:21 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531498461; cv=none; d=google.com; s=arc-20160816; b=lxZDlopJAMp5Yjho6frD3NgLbvDwBxIeiaejBuOqLA6UmskCq7s/MehXNDMXevGmZO 6qXZaaIzR40+KRbo+++W70glojuBbVdeH9PuCMQaXIxKoT5G6iJfm1XMR3991Hp2n3Bd FTtneEOJya0l48HTSFw/+orEhaUkeSTXVx8W9UV1/kpFfnw+Wr/e4ju1B2glAcZSgkeb xjGOcM0F4ZVrQ4r6dGOidLY63/gJHLw6pJ5YixrrvEdEikh0xFDuFFIgES44OWmS8rVj OEPSX1Tt8kr2mM5HI7CC1UwiBaalBbukMhlifQVJswmJ2SCSkCQA5rKlalUam/jX0hDI 6DxQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:delivered-to:sender:list-help :list-post:list-archive:list-unsubscribe:list-id:precedence :mailing-list:dkim-signature:domainkey-signature :arc-authentication-results; bh=RfYz+/3UCBdqV6LIlLl4he1g3b0SirfD2a4bTokNJ1s=; b=E2VG1VN7FnbUwqhvcco5wPWeeV4MMvyTX73QCkoC0zHklJ2FvcnlpW51nJCawU/VzC zfznpxkldHyQj1jtmBQk7KxeKi06ZjEZunNAExjycGEYn9+TPnjZv2XP97cRcToN5dIf 8BWoKLouR7SQAB4rOWrGDkCFqwS0H26Xics9HO3yCtOXQzVrxV/qtm8dwBHVfBn4ekJB BNPvZ0Dafkd2jhKJrjgkB99wLfL2OP0fr3zk/WM3rsGhuhLw5zHcxFgtKS42QaL+2AeA PaTCQOWvh/2kXN0V0IJcrVOyezhsQ7epabVVt/FUMlFUSslu0QLYSX5EG3hi3Y/uK7By 8zUQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gcc.gnu.org header.s=default header.b=RuvBrYpu; spf=pass (google.com: domain of gcc-patches-return-481516-patch=linaro.org@gcc.gnu.org designates 209.132.180.131 as permitted sender) smtp.mailfrom="gcc-patches-return-481516-patch=linaro.org@gcc.gnu.org" Return-Path: Received: from sourceware.org (server1.sourceware.org. [209.132.180.131]) by mx.google.com with ESMTPS id a4-v6si23722244pgl.9.2018.07.13.09.14.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 13 Jul 2018 09:14:21 -0700 (PDT) Received-SPF: pass (google.com: domain of gcc-patches-return-481516-patch=linaro.org@gcc.gnu.org designates 209.132.180.131 as permitted sender) client-ip=209.132.180.131; Authentication-Results: mx.google.com; dkim=pass header.i=@gcc.gnu.org header.s=default header.b=RuvBrYpu; spf=pass (google.com: domain of gcc-patches-return-481516-patch=linaro.org@gcc.gnu.org designates 209.132.180.131 as permitted sender) smtp.mailfrom="gcc-patches-return-481516-patch=linaro.org@gcc.gnu.org" DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:from :to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-type:content-transfer-encoding; q=dns; s= default; b=SFIuOKg9l8iDHxs+LH5XblIh3soTRDXmTFALoXDa60zy8E28JFVrO Tx+telW/qEd3RIqp21CTY3QpesqPfX1Ya3KCAuuBkwg78mC6ip/EJ6BdrHPSI6uo isViil/+ZIISrZEh5TY0mhwXOu0dXNZ9zI9bUXHN0uu6ZXZ3sn+rAE= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:from :to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-type:content-transfer-encoding; s=default; bh=QRJOsm3uj6B1Z8JynrZ4hLjgLqA=; b=RuvBrYpuykxh69iORlYAU8+xixC8 Joz6kjIQJtkfFKZM0lN9nko0wyQaEi9jsLGGUDcM2Y6jZkVl4clMTf/4kSeOeuJr LsWx+z+up4aWWQ5/fYhXsyGjW8/L5lvB8uT0d0uczJ1H2EAmgBFPe2Iex3oa3A4O qj4tnZ4cwYI41CQ= Received: (qmail 22325 invoked by alias); 13 Jul 2018 16:14:06 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 22316 invoked by uid 89); 13 Jul 2018 16:14:06 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-27.6 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx07-00178001.pphosted.com Received: from mx08-00178001.pphosted.com (HELO mx07-00178001.pphosted.com) (91.207.212.93) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 13 Jul 2018 16:14:04 +0000 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx08-.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id w6DG48et021422; Fri, 13 Jul 2018 18:14:01 +0200 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx08-00178001.pphosted.com with ESMTP id 2k6tcs1apf-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Fri, 13 Jul 2018 18:14:01 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id F19A731; Fri, 13 Jul 2018 16:14:00 +0000 (GMT) Received: from Webmail-eu.st.com (sfhdag5node1.st.com [10.75.127.13]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id D0F6CA6AB; Fri, 13 Jul 2018 16:14:00 +0000 (GMT) Received: from gnb.st.com (10.75.127.48) by SFHDAG5NODE1.st.com (10.75.127.13) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Fri, 13 Jul 2018 18:14:00 +0200 From: To: CC: Subject: [ARM/FDPIC v2 06/21] [ARM] FDPIC: Add support for c++ exceptions Date: Fri, 13 Jul 2018 18:11:01 +0200 Message-ID: <20180713161136.29104-7-christophe.lyon@st.com> In-Reply-To: <20180713161136.29104-1-christophe.lyon@st.com> References: <20180713161136.29104-1-christophe.lyon@st.com> MIME-Version: 1.0 X-IsSubscribed: yes From: Christophe Lyon The main difference with existing support is that function addresses are function descriptor addresses instead. This means that all code dealing with function pointers now has to cope with function descriptors instead. For the same reason, Linux kernel helpers can no longer be called by dereferencing their address, so we implement the same functionality as a regular function here. When restoring a function address, we also have to restore the FDPIC register value (r9). 2018-XX-XX Christophe Lyon Mickaël Guêné gcc/ * ginclude/unwind-arm-common.h (unwinder_cache): Add reserved5 field. libgcc/ * config/arm/linux-atomic.c (__kernel_cmpxchg): Add FDPIC support. (__kernel_dmb): Likewise. (__fdpic_cmpxchg): New function. (__fdpic_dmb): New function. * config/arm/unwind-arm.h (gnu_Unwind_Find_got): New function. (_Unwind_decode_typeinfo_ptr): Add FDPIC support. * unwindo-arm-common.inc (UCB_PR_GOT): New. (funcdesc_t): New struct. (get_eit_entry): Add FDPIC support. (unwind_phase2): Likewise. (unwind_phase2_forced): Likewise. (__gnu_Unwind_RaiseException): Likewise. (__gnu_Unwind_Resume): Likewise. (__gnu_Unwind_Backtrace): Likewise. * unwind-pe.h (read_encoded_value_with_base): Likewise. libstdc++/ * libsupc++/eh_personality.cc (get_ttype_entry): Add FDPIC support. Change-Id: Ic0841eb3d7bfb0b3f6d187cd52a660b8fd394d85 -- 2.6.3 diff --git a/gcc/ginclude/unwind-arm-common.h b/gcc/ginclude/unwind-arm-common.h index 8a1a919..150bd0f 100644 --- a/gcc/ginclude/unwind-arm-common.h +++ b/gcc/ginclude/unwind-arm-common.h @@ -91,7 +91,7 @@ extern "C" { _uw reserved2; /* Personality routine address */ _uw reserved3; /* Saved callsite address */ _uw reserved4; /* Forced unwind stop arg */ - _uw reserved5; + _uw reserved5; /* Personality routine GOT value in FDPIC mode. */ } unwinder_cache; /* Propagation barrier cache (valid after phase 1): */ diff --git a/libgcc/config/arm/linux-atomic.c b/libgcc/config/arm/linux-atomic.c index d334c58..161d1ce 100644 --- a/libgcc/config/arm/linux-atomic.c +++ b/libgcc/config/arm/linux-atomic.c @@ -25,11 +25,49 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see /* Kernel helper for compare-and-exchange. */ typedef int (__kernel_cmpxchg_t) (int oldval, int newval, int *ptr); +#if __FDPIC__ +/* Non-FDPIC ABIs call __kernel_cmpxchg directly by dereferencing its + address, but under FDPIC we would generate a broken call + sequence. That's why we have to implement __kernel_cmpxchg and + __kernel_dmb here: this way, the FDPIC call sequence works. */ +#define __kernel_cmpxchg __fdpic_cmpxchg +#else #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0) +#endif /* Kernel helper for memory barrier. */ typedef void (__kernel_dmb_t) (void); +#if __FDPIC__ +#define __kernel_dmb __fdpic_dmb +#else #define __kernel_dmb (*(__kernel_dmb_t *) 0xffff0fa0) +#endif + +#if __FDPIC__ +static int __fdpic_cmpxchg (int oldval, int newval, int *ptr) +{ + int result; + + asm volatile ("1: ldrex r3, [%[ptr]]\n\t" + "subs r3, r3, %[oldval]\n\t" + "itt eq\n\t" + "strexeq r3, %[newval], [%[ptr]]\n\t" + "teqeq r3, #1\n\t" + "it eq\n\t" + "beq 1b\n\t" + "rsbs %[result], r3, #0\n\t" + : [result] "=r" (result) + : [oldval] "r" (oldval) , [newval] "r" (newval), [ptr] "r" (ptr) + : "r3"); + return result; +} + +static void __fdpic_dmb () +{ + asm volatile ("dmb\n\t"); +} + +#endif /* Note: we implement byte, short and int versions of atomic operations using the above kernel helpers; see linux-atomic-64bit.c for "long long" (64-bit) diff --git a/libgcc/config/arm/unwind-arm.h b/libgcc/config/arm/unwind-arm.h index 9f7d3f2..5874b9b 100644 --- a/libgcc/config/arm/unwind-arm.h +++ b/libgcc/config/arm/unwind-arm.h @@ -36,6 +36,25 @@ #ifdef __cplusplus extern "C" { #endif +_Unwind_Ptr __attribute__((weak)) __gnu_Unwind_Find_got (_Unwind_Ptr); + +static inline _Unwind_Ptr gnu_Unwind_Find_got (_Unwind_Ptr ptr) +{ + _Unwind_Ptr res; + + if (__gnu_Unwind_Find_got) + res = __gnu_Unwind_Find_got (ptr); + else + { + asm volatile ("mov %[result], r9" + : [result]"=r" (res) + : + :); + } + + return res; +} + /* Decode an R_ARM_TARGET2 relocation. */ static inline _Unwind_Word _Unwind_decode_typeinfo_ptr (_Unwind_Word base __attribute__ ((unused)), @@ -48,7 +67,12 @@ extern "C" { if (!tmp) return 0; -#if (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \ +#if __FDPIC__ + /* For FDPIC, we store the offset of the GOT entry. */ + /* So, first get GOT from dynamic linker and then use indirect access. */ + tmp += gnu_Unwind_Find_got (ptr); + tmp = *(_Unwind_Word *) tmp; +#elif (defined(linux) && !defined(__uClinux__)) || defined(__NetBSD__) \ || defined(__FreeBSD__) || defined(__fuchsia__) /* Pc-relative indirect. */ #define _GLIBCXX_OVERRIDE_TTYPE_ENCODING (DW_EH_PE_pcrel | DW_EH_PE_indirect) diff --git a/libgcc/unwind-arm-common.inc b/libgcc/unwind-arm-common.inc index 76f8fc3..d7c611f 100644 --- a/libgcc/unwind-arm-common.inc +++ b/libgcc/unwind-arm-common.inc @@ -62,6 +62,7 @@ __gnu_Unwind_Find_exidx (_Unwind_Ptr, int *); #define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2) #define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3) #define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4) +#define UCB_PR_GOT(ucbp) ((ucbp)->unwinder_cache.reserved5) /* Unwind descriptors. */ @@ -85,6 +86,16 @@ typedef struct __EIT_entry _uw content; } __EIT_entry; +#ifdef __FDPIC__ +#define FDPIC_REGNUM 9 + +/* Only used in FDPIC case. */ +struct funcdesc_t { + unsigned int ptr; + unsigned int got; +}; +#endif + /* Assembly helper functions. */ /* Restore core register state. Never returns. */ @@ -259,7 +270,21 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address) { /* One of the predefined standard routines. */ _uw idx = (*(_uw *) ucbp->pr_cache.ehtp >> 24) & 0xf; +#if __FDPIC__ + { + struct funcdesc_t *funcdesc + = (struct funcdesc_t *) __gnu_unwind_get_pr_addr (idx); + if (funcdesc) + { + UCB_PR_ADDR (ucbp) = funcdesc->ptr; + UCB_PR_GOT (ucbp) = funcdesc->got; + } + else + UCB_PR_ADDR (ucbp) = 0; + } +#else UCB_PR_ADDR (ucbp) = __gnu_unwind_get_pr_addr (idx); +#endif if (UCB_PR_ADDR (ucbp) == 0) { /* Failed */ @@ -270,6 +295,10 @@ get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address) { /* Execute region offset to PR */ UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp); +#if __FDPIC__ + UCB_PR_GOT (ucbp) + = (unsigned int) gnu_Unwind_Find_got ((_Unwind_Ptr) UCB_PR_ADDR (ucbp)); +#endif } return _URC_OK; } @@ -291,14 +320,29 @@ unwind_phase2 (_Unwind_Control_Block * ucbp, phase2_vrs * vrs) UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC(vrs); /* Call the pr to decide what to do. */ +#if __FDPIC__ + { + volatile struct funcdesc_t funcdesc; + funcdesc.ptr = UCB_PR_ADDR (ucbp); + funcdesc.got = UCB_PR_GOT (ucbp); + pr_result = ((personality_routine) &funcdesc) + (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs); + } +#else pr_result = ((personality_routine) UCB_PR_ADDR (ucbp)) (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs); +#endif } while (pr_result == _URC_CONTINUE_UNWIND); if (pr_result != _URC_INSTALL_CONTEXT) abort(); +#if __FDPIC__ + /* r9 could have been lost due to PLT jump. Restore correct value. */ + vrs->core.r[FDPIC_REGNUM] = gnu_Unwind_Find_got (VRS_PC (vrs)); +#endif + uw_restore_core_regs (vrs, &vrs->core); } @@ -346,8 +390,18 @@ unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs, next_vrs = saved_vrs; /* Call the pr to decide what to do. */ +#if __FDPIC__ + { + volatile struct funcdesc_t funcdesc; + funcdesc.ptr = UCB_PR_ADDR (ucbp); + funcdesc.got = UCB_PR_GOT (ucbp); + pr_result = ((personality_routine) &funcdesc) + (action, ucbp, (void *) &next_vrs); + } +#else pr_result = ((personality_routine) UCB_PR_ADDR (ucbp)) (action, ucbp, (void *) &next_vrs); +#endif saved_vrs.prev_sp = VRS_SP (&next_vrs); } @@ -384,6 +438,11 @@ unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs, return _URC_FAILURE; } +#if __FDPIC__ + /* r9 could have been lost due to PLT jump. Restore correct value. */ + saved_vrs.core.r[FDPIC_REGNUM] = gnu_Unwind_Find_got (VRS_PC (&saved_vrs)); +#endif + uw_restore_core_regs (&saved_vrs, &saved_vrs.core); } @@ -429,8 +488,18 @@ __gnu_Unwind_RaiseException (_Unwind_Control_Block * ucbp, return _URC_FAILURE; /* Call the pr to decide what to do. */ +#if __FDPIC__ + { + volatile struct funcdesc_t funcdesc; + funcdesc.ptr = UCB_PR_ADDR (ucbp); + funcdesc.got = UCB_PR_GOT (ucbp); + pr_result = ((personality_routine) &funcdesc) + (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs); + } +#else pr_result = ((personality_routine) UCB_PR_ADDR (ucbp)) (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs); +#endif } while (pr_result == _URC_CONTINUE_UNWIND); @@ -488,13 +557,27 @@ __gnu_Unwind_Resume (_Unwind_Control_Block * ucbp, phase2_vrs * entry_vrs) } /* Call the cached PR. */ +#if __FDPIC__ + { + volatile struct funcdesc_t funcdesc; + funcdesc.ptr = UCB_PR_ADDR (ucbp); + funcdesc.got = UCB_PR_GOT (ucbp); + pr_result = ((personality_routine) &funcdesc) + (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs); + } +#else pr_result = ((personality_routine) UCB_PR_ADDR (ucbp)) (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs); +#endif switch (pr_result) { case _URC_INSTALL_CONTEXT: /* Upload the registers to enter the landing pad. */ +#if __FDPIC__ + /* r9 could have been lost due to PLT jump. Restore correct value. */ + entry_vrs->core.r[FDPIC_REGNUM] = gnu_Unwind_Find_got (VRS_PC (entry_vrs)); +#endif uw_restore_core_regs (entry_vrs, &entry_vrs->core); case _URC_CONTINUE_UNWIND: @@ -586,9 +669,20 @@ __gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument, } /* Call the pr to decide what to do. */ +#if __FDPIC__ + { + volatile struct funcdesc_t funcdesc; + funcdesc.ptr = UCB_PR_ADDR (ucbp); + funcdesc.got = UCB_PR_GOT (ucbp); + code = ((personality_routine) &funcdesc) + (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND, + ucbp, (void *) &saved_vrs); + } +#else code = ((personality_routine) UCB_PR_ADDR (ucbp)) (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND, ucbp, (void *) &saved_vrs); +#endif } while (code != _URC_END_OF_STACK && code != _URC_FAILURE); diff --git a/libgcc/unwind-pe.h b/libgcc/unwind-pe.h index dd5ae95..9c5177f 100644 --- a/libgcc/unwind-pe.h +++ b/libgcc/unwind-pe.h @@ -259,10 +259,27 @@ read_encoded_value_with_base (unsigned char encoding, _Unwind_Ptr base, if (result != 0) { +#if __FDPIC__ + /* FDPIC relative addresses imply taking the GOT address + into account. */ + if ((encoding & DW_EH_PE_pcrel) && (encoding & DW_EH_PE_indirect)) + { + result += gnu_Unwind_Find_got ((_Unwind_Ptr) u); + result = *(_Unwind_Internal_Ptr *) result; + } + else + { + result += ((encoding & 0x70) == DW_EH_PE_pcrel + ? (_Unwind_Internal_Ptr) u : base); + if (encoding & DW_EH_PE_indirect) + result = *(_Unwind_Internal_Ptr *) result; + } +#else result += ((encoding & 0x70) == DW_EH_PE_pcrel ? (_Unwind_Internal_Ptr) u : base); if (encoding & DW_EH_PE_indirect) result = *(_Unwind_Internal_Ptr *) result; +#endif } } diff --git a/libstdc++-v3/libsupc++/eh_personality.cc b/libstdc++-v3/libsupc++/eh_personality.cc index 1b336c7..7b26b8d 100644 --- a/libstdc++-v3/libsupc++/eh_personality.cc +++ b/libstdc++-v3/libsupc++/eh_personality.cc @@ -93,7 +93,15 @@ get_ttype_entry (lsda_header_info *info, _uleb128_t i) _Unwind_Ptr ptr; i *= size_of_encoded_value (info->ttype_encoding); - read_encoded_value_with_base (info->ttype_encoding, info->ttype_base, + read_encoded_value_with_base ( +#if __FDPIC__ + /* Force these flags to nake sure to + take the GOT into account. */ + (DW_EH_PE_pcrel | DW_EH_PE_indirect), +#else + info->ttype_encoding, +#endif + info->ttype_base, info->TType - i, &ptr); return reinterpret_cast(ptr);