From patchwork Mon Jul 25 13:23:04 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Andre Vieira (lists)" X-Patchwork-Id: 652265 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3ryhlj0Tvmz9t1b for ; Mon, 25 Jul 2016 23:23:28 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b=naqqV3+Q; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender :subject:to:references:from:message-id:date:mime-version :in-reply-to:content-type; q=dns; s=default; b=lemz9TAx+MZd7Yeiv uidVrNKaR1DCVU5FQBVlCWEq377xTVNnfGqRNCgigMj4sGCmW8dfAVLC7WcAZKqP w/aazpx52RL61WHVklCKQfaZIRC07FkmUAfqAhAsN+KbQedbO1n3F8Efk1Kf9iD1 6HWxTo+AutJa8wF21fqbqNj1T0= 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 :subject:to:references:from:message-id:date:mime-version :in-reply-to:content-type; s=default; bh=/f5wqGw5utGUPg8EV9/Z8g5 iOiM=; b=naqqV3+Qt0QJUJSOX1KwhQSO5Rb/n5e7lSrJTeRlFz49OuUo2JHSt+l 0YAGHKFFXYrKFboostvd0uywgDqV40nPMIDneysk08hxZUxrF/YdRO+b+LIfN+fT 9x2177MGPVItBp64tAmpWmU2e0TUYGQn1hV233LOQEzMYTKUm1pQ= Received: (qmail 87883 invoked by alias); 25 Jul 2016 13:23:19 -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 87869 invoked by uid 89); 25 Jul 2016 13:23:18 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.9 required=5.0 tests=BAYES_00, KAM_LOTSOFHASH, RP_MATCHES_RCVD, SPF_PASS autolearn=ham version=3.3.2 spammy=trailer, strlen, secure, gateway X-HELO: foss.arm.com Received: from foss.arm.com (HELO foss.arm.com) (217.140.101.70) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 25 Jul 2016 13:23:08 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 37AD528 for ; Mon, 25 Jul 2016 06:24:21 -0700 (PDT) Received: from [10.2.206.221] (e107157-lin.cambridge.arm.com [10.2.206.221]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E0D593F21A for ; Mon, 25 Jul 2016 06:23:05 -0700 (PDT) Subject: [PATCH 3/7, GCC, ARM, V8M] ARMv8-M Security Extension's cmse_nonsecure_entry: __acle_se label and bxns return To: gcc-patches@gcc.gnu.org References: <5796116C.6010100@arm.com> From: "Andre Vieira (lists)" Message-ID: <579612B8.7030401@arm.com> Date: Mon, 25 Jul 2016 14:23:04 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <5796116C.6010100@arm.com> X-IsSubscribed: yes This patch extends support for the ARMv8-M Security Extensions 'cmse_nonsecure_entry' attribute in two ways: 1) Generate two labels for the function, the regular function name and one with the function's name appended to '__acle_se_', this will trigger the linker to create a secure gateway veneer for this entry function. 2) Return from cmse_nonsecure_entry marked functions using bxns. See Section 5.4 of ARM®v8-M Security Extensions (http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/index.html). *** gcc/ChangeLog *** 2016-07-25 Andre Vieira Thomas Preud'homme * config/arm/arm.c (use_return_insn): Change to return with bxns when cmse_nonsecure_entry. (output_return_instruction): Likewise. (arm_output_function_prologue): Likewise. (thumb_pop): Likewise. (thumb_exit): Likewise. (arm_function_ok_for_sibcall): Disable sibcall for entry functions. (arm_asm_declare_function_name): New. * config/arm/arm-protos.h (arm_asm_declare_function_name): New. * config/arm/elf.h (ASM_DECLARE_FUNCTION_NAME): Redefine to use arm_asm_declare_function_name. *** gcc/testsuite/ChangeLog *** 2016-07-25 Andre Vieira Thomas Preud'homme * gcc.target/arm/cmse/cmse-2.c: New. * gcc.target/arm/cmse/cmse-4.c: New. diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h index 0754fb7252a8b86ffacc0cee4598686752af6e56..1d2e35b52f631570450b6c8eaf077e18e9b99203 100644 --- a/gcc/config/arm/arm-protos.h +++ b/gcc/config/arm/arm-protos.h @@ -31,6 +31,7 @@ extern int arm_volatile_func (void); extern void arm_expand_prologue (void); extern void arm_expand_epilogue (bool); extern void arm_declare_function_name (FILE *, const char *, tree); +extern void arm_asm_declare_function_name (FILE *, const char *, tree); extern void thumb2_expand_return (bool); extern const char *arm_strip_name_encoding (const char *); extern void arm_asm_output_labelref (FILE *, const char *); diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 11417ab3c2f7101866ee5d6b100913480e5c336e..9fba371768b1eba3a11dc8aa5d6acf8cc30f464d 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -3866,6 +3866,11 @@ use_return_insn (int iscond, rtx sibling) return 0; } + /* ARMv8-M nonsecure entry function need to use bxns to return and thus need + several instructions if anything needs to be popped. */ + if (saved_int_regs && IS_CMSE_ENTRY (func_type)) + return 0; + /* If there are saved registers but the LR isn't saved, then we need two instructions for the return. */ if (saved_int_regs && !(saved_int_regs & (1 << LR_REGNUM))) @@ -6903,6 +6908,11 @@ arm_function_ok_for_sibcall (tree decl, tree exp) if (IS_INTERRUPT (func_type)) return false; + /* ARMv8-M non-secure entry functions need to return with bxns which is only + generated for entry functions themselves. */ + if (IS_CMSE_ENTRY (arm_current_func_type ())) + return false; + if (!VOID_TYPE_P (TREE_TYPE (DECL_RESULT (cfun->decl)))) { /* Check that the return value locations are the same. For @@ -19739,6 +19749,7 @@ output_return_instruction (rtx operand, bool really_return, bool reverse, (e.g. interworking) then we can load the return address directly into the PC. Otherwise we must load it into LR. */ if (really_return + && !IS_CMSE_ENTRY (func_type) && (IS_INTERRUPT (func_type) || !TARGET_INTERWORK)) return_reg = reg_names[PC_REGNUM]; else @@ -19879,8 +19890,10 @@ output_return_instruction (rtx operand, bool really_return, bool reverse, break; default: + if (IS_CMSE_ENTRY (func_type)) + snprintf (instr, sizeof (instr), "bxns%s\t%%|lr", conditional); /* Use bx if it's available. */ - if (arm_arch5 || arm_arch4t) + else if (arm_arch5 || arm_arch4t) sprintf (instr, "bx%s\t%%|lr", conditional); else sprintf (instr, "mov%s\t%%|pc, %%|lr", conditional); @@ -19893,6 +19906,42 @@ output_return_instruction (rtx operand, bool really_return, bool reverse, return ""; } +/* Output in FILE asm statements needed to declare the NAME of the function + defined by its DECL node. */ + +void +arm_asm_declare_function_name (FILE *file, const char *name, tree decl) +{ + size_t cmse_name_len; + char *cmse_name = 0; + char cmse_prefix[] = "__acle_se_"; + + if (use_cmse && lookup_attribute ("cmse_nonsecure_entry", + DECL_ATTRIBUTES (decl))) + { + cmse_name_len = sizeof (cmse_prefix) + strlen (name); + cmse_name = XALLOCAVEC (char, cmse_name_len); + snprintf (cmse_name, cmse_name_len, "%s%s", cmse_prefix, name); + targetm.asm_out.globalize_label (file, cmse_name); + } + + if (cmse_name) + { + ARM_DECLARE_FUNCTION_NAME (file, cmse_name, decl); + ASM_OUTPUT_TYPE_DIRECTIVE (file, cmse_name, "function"); + } + + ARM_DECLARE_FUNCTION_NAME (file, name, decl); + ASM_OUTPUT_TYPE_DIRECTIVE (file, name, "function"); + ASM_DECLARE_RESULT (file, DECL_RESULT (decl)); + ASM_OUTPUT_LABEL (file, name); + + if (cmse_name) + ASM_OUTPUT_LABEL (file, cmse_name); + + ARM_OUTPUT_FN_UNWIND (file, TRUE); +} + /* Write the function name into the code section, directly preceding the function prologue. @@ -19942,10 +19991,6 @@ arm_output_function_prologue (FILE *f, HOST_WIDE_INT frame_size) { unsigned long func_type; - /* ??? Do we want to print some of the below anyway? */ - if (TARGET_THUMB1) - return; - /* Sanity check. */ gcc_assert (!arm_ccfsm_state && !arm_target_insn); @@ -19980,6 +20025,8 @@ arm_output_function_prologue (FILE *f, HOST_WIDE_INT frame_size) asm_fprintf (f, "\t%@ Nested: function declared inside another function.\n"); if (IS_STACKALIGN (func_type)) asm_fprintf (f, "\t%@ Stack Align: May be called with mis-aligned SP.\n"); + if (IS_CMSE_ENTRY (func_type)) + asm_fprintf (f, "\t%@ Non-secure entry function: called from non-secure code.\n"); asm_fprintf (f, "\t%@ args = %d, pretend = %d, frame = %wd\n", crtl->args.size, @@ -24033,8 +24080,8 @@ thumb_pop (FILE *f, unsigned long mask) if (mask & (1 << PC_REGNUM)) { /* Catch popping the PC. */ - if (TARGET_INTERWORK || TARGET_BACKTRACE - || crtl->calls_eh_return) + if (TARGET_INTERWORK || TARGET_BACKTRACE || crtl->calls_eh_return + || IS_CMSE_ENTRY (arm_current_func_type ())) { /* The PC is never poped directly, instead it is popped into r3 and then BX is used. */ @@ -24095,7 +24142,10 @@ thumb_exit (FILE *f, int reg_containing_return_addr) if (crtl->calls_eh_return) asm_fprintf (f, "\tadd\t%r, %r\n", SP_REGNUM, ARM_EH_STACKADJ_REGNUM); - asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr); + if (IS_CMSE_ENTRY (arm_current_func_type ())) + asm_fprintf (f, "\tbxns\t%r\n", reg_containing_return_addr); + else + asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr); return; } /* Otherwise if we are not supporting interworking and we have not created @@ -24104,7 +24154,8 @@ thumb_exit (FILE *f, int reg_containing_return_addr) else if (!TARGET_INTERWORK && !TARGET_BACKTRACE && !is_called_in_ARM_mode (current_function_decl) - && !crtl->calls_eh_return) + && !crtl->calls_eh_return + && !IS_CMSE_ENTRY (arm_current_func_type ())) { asm_fprintf (f, "\tpop\t{%r}\n", PC_REGNUM); return; @@ -24327,7 +24378,10 @@ thumb_exit (FILE *f, int reg_containing_return_addr) asm_fprintf (f, "\tadd\t%r, %r\n", SP_REGNUM, ARM_EH_STACKADJ_REGNUM); /* Return to caller. */ - asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr); + if (IS_CMSE_ENTRY (arm_current_func_type ())) + asm_fprintf (f, "\tbxns\t%r\n", reg_containing_return_addr); + else + asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr); } /* Scan INSN just before assembler is output for it. @@ -25208,6 +25262,12 @@ thumb2_expand_return (bool simple_return) if (!simple_return && saved_regs_mask) { + /* TODO: Verify that this path is never taken for cmse_nonsecure_entry + functions or adapt code to handle according to ACLE. This path should + not be reachable for cmse_nonsecure_entry functions though we prefer + to guard it for now to ensure that future code changes do not silently + change this behavior. */ + gcc_assert (!IS_CMSE_ENTRY (arm_current_func_type ())); if (num_regs == 1) { rtx par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (2)); @@ -25625,6 +25685,7 @@ arm_expand_epilogue (bool really_return) if (ARM_FUNC_TYPE (func_type) != ARM_FT_INTERWORKED && (TARGET_ARM || ARM_FUNC_TYPE (func_type) == ARM_FT_NORMAL) + && !IS_CMSE_ENTRY (func_type) && !IS_STACKALIGN (func_type) && really_return && crtl->args.pretend_args_size == 0 diff --git a/gcc/config/arm/elf.h b/gcc/config/arm/elf.h index 246de5492665ba2a0292736a9c53fbaaef184d72..fd8fc1cb0e6aa2212774068513233d6e818eeec8 100644 --- a/gcc/config/arm/elf.h +++ b/gcc/config/arm/elf.h @@ -75,16 +75,7 @@ /* We might need a ARM specific header to function declarations. */ #undef ASM_DECLARE_FUNCTION_NAME -#define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \ - do \ - { \ - ARM_DECLARE_FUNCTION_NAME (FILE, NAME, DECL); \ - ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \ - ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \ - ASM_OUTPUT_LABEL(FILE, NAME); \ - ARM_OUTPUT_FN_UNWIND (FILE, TRUE); \ - } \ - while (0) +#define ASM_DECLARE_FUNCTION_NAME arm_asm_declare_function_name /* We might need an ARM specific trailer for function declarations. */ #undef ASM_DECLARE_FUNCTION_SIZE diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-10.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-10.c new file mode 100644 index 0000000000000000000000000000000000000000..1a91ac39ee37ef20495e047b402d3f5edc60a613 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-10.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-mcmse" } */ + +void +foo (void) {} + +/* { dg-final { scan-assembler-not "bxns" } } */ +/* { dg-final { scan-assembler "foo:" } } */ +/* { dg-final { scan-assembler-not "__acle_se_foo:" } } */ diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c new file mode 100644 index 0000000000000000000000000000000000000000..6f930ab04a1097c64097a4e003296bbe85733319 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c @@ -0,0 +1,27 @@ +/* { dg-do compile } */ +/* { dg-options "-mcmse" } */ + +struct span { + int a, b; +}; + +extern int qux (void); + +void __attribute__ ((cmse_nonsecure_entry)) +foo (void) {} + +static void __attribute__ ((cmse_nonsecure_entry)) +bar (void) {} /* { dg-warning "has no effect on functions with static linkage" } */ + +int __attribute__ ((cmse_nonsecure_entry)) +baz (void) +{ + return qux (); +} + +/* { dg-final { scan-assembler-times "bxns" 2 } } */ +/* { dg-final { scan-assembler "foo:" } } */ +/* { dg-final { scan-assembler "__acle_se_foo:" } } */ +/* { dg-final { scan-assembler-not "__acle_se_bar:" } } */ +/* { dg-final { scan-assembler "baz:" } } */ +/* { dg-final { scan-assembler "__acle_se_baz:" } } */ diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-9.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-9.c new file mode 100644 index 0000000000000000000000000000000000000000..65200bcf29b219706911bbb799c847aefc92cb1c --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-9.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-skip-if "Testing exclusion of -mcmse" { arm-*-* } { "-mcmse" } { "" } } */ + + +int __attribute__ ((cmse_nonsecure_entry)) +foo (int a) +{ + return a + 1; +} + +/* { dg-final { scan-assembler "foo:" } } */ +/* { dg-final { scan-assembler-not "__acle_se_foo:" } } */