From patchwork Tue Jan 11 10:06:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 49829 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 9293738A7C1D for ; Tue, 11 Jan 2022 10:07:10 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9293738A7C1D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1641895630; bh=YxOhtxxB7BMD/3TfjTbHiqryhJX7v2cjRl4XrXn2gys=; h=To:Subject:In-Reply-To:References:Date:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=Ed7tLJ5VUJx/wYA7yczOcE5PEwt4valN9alfRNe0WjhiRKo+27zwJ5IkdrTpq0D5J ejuehmTKs1lR1Y00tx6zDuafvBW59sRMLlBQ8DGniEkWI3bJ2PQ03uCX1VkqUKhxkU aBQH50Pun6WphvphzrdHGHqK3YFNiav+jE8+6Jjs= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id B93A838A140C for ; Tue, 11 Jan 2022 10:06:49 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org B93A838A140C Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-515-IE2cSuO_P2SNrIqUNkGThA-1; Tue, 11 Jan 2022 05:06:48 -0500 X-MC-Unique: IE2cSuO_P2SNrIqUNkGThA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 37D1081EE60; Tue, 11 Jan 2022 10:06:47 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.102]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E8F0B1F431; Tue, 11 Jan 2022 10:06:45 +0000 (UTC) To: libc-alpha@sourceware.org Subject: [PATCH 1/2] i386: Always treat %ebx as an allocatable register In-Reply-To: References: X-From-Line: e5609b0199e5f16f9b1c1178ea642ff0a3724152 Mon Sep 17 00:00:00 2001 Message-Id: Date: Tue, 11 Jan 2022 11:06:44 +0100 User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Florian Weimer via Libc-alpha From: Florian Weimer Reply-To: Florian Weimer Cc: Jakub Jelinek Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" !CAN_USE_REGISTER_ASM_EBP also disables the direct use of %ebx in system calls, but that is not actually needed anymore. --- sysdeps/unix/sysv/linux/i386/sysdep.h | 192 ++++---------------------- 1 file changed, 25 insertions(+), 167 deletions(-) diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h index 66c2833a49..fcd78e3157 100644 --- a/sysdeps/unix/sysv/linux/i386/sysdep.h +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h @@ -239,35 +239,6 @@ extern int __syscall_error (int) attribute_hidden __attribute__ ((__regparm__ (1))); #ifndef OPTIMIZE_FOR_GCC_5 -/* We need some help from the assembler to generate optimal code. We - define some macros here which later will be used. */ -asm (".L__X'%ebx = 1\n\t" - ".L__X'%ecx = 2\n\t" - ".L__X'%edx = 2\n\t" - ".L__X'%eax = 3\n\t" - ".L__X'%esi = 3\n\t" - ".L__X'%edi = 3\n\t" - ".L__X'%ebp = 3\n\t" - ".L__X'%esp = 3\n\t" - ".macro bpushl name reg\n\t" - ".if 1 - \\name\n\t" - ".if 2 - \\name\n\t" - "error\n\t" - ".else\n\t" - "xchgl \\reg, %ebx\n\t" - ".endif\n\t" - ".endif\n\t" - ".endm\n\t" - ".macro bpopl name reg\n\t" - ".if 1 - \\name\n\t" - ".if 2 - \\name\n\t" - "error\n\t" - ".else\n\t" - "xchgl \\reg, %ebx\n\t" - ".endif\n\t" - ".endif\n\t" - ".endm\n\t"); - /* Six-argument syscalls use an out-of-line helper, because an inline asm using all registers apart from %esp cannot work reliably and the assembler does not support describing an asm that saves and @@ -379,187 +350,74 @@ struct libc_do_syscall_args (int) resultvar; }) #if I386_USE_SYSENTER -# ifdef OPTIMIZE_FOR_GCC_5 -# ifdef PIC -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ +# ifdef PIC +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "call *%%gs:%P2" \ : "=a" (resultvar) \ : "a" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ ASMARGS_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "call *%%gs:%P2" \ : "=a" (resultvar) \ : "a" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ ASMARGS_##nr(args) : "memory", "cc") -# else -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ +# else /* I386_USE_SYSENTER && !PIC */ +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "call *_dl_sysinfo" \ : "=a" (resultvar) \ : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "call *_dl_sysinfo" \ : "=a" (resultvar) \ : "a" (name) ASMARGS_##nr(args) : "memory", "cc") -# endif -# else /* GCC 5 */ -# ifdef PIC -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "movl %1, %%eax\n\t" \ - "call *%%gs:%P2\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "i" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ - ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "call *%%gs:%P2\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "0" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ - ASMFMT_##nr(args) : "memory", "cc") -# else -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "movl %1, %%eax\n\t" \ - "call *_dl_sysinfo\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "call *_dl_sysinfo\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "0" (name) ASMFMT_##nr(args) : "memory", "cc") -# endif -# endif /* GCC 5 */ -#else -# ifdef OPTIMIZE_FOR_GCC_5 -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ +# endif /* I386_USE_SYSENTER && !PIC */ +#else /* !I386_USE_SYSENTER */ +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "int $0x80" \ : "=a" (resultvar) \ : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "int $0x80" \ : "=a" (resultvar) \ : "a" (name) ASMARGS_##nr(args) : "memory", "cc") -# else /* GCC 5 */ -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "movl %1, %%eax\n\t" \ - "int $0x80\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "int $0x80\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "0" (name) ASMFMT_##nr(args) : "memory", "cc") -# endif /* GCC 5 */ -#endif +#endif /* !I386_USE_SYSENTER */ -#define LOADARGS_0 -#ifdef __PIC__ -# if I386_USE_SYSENTER && defined PIC -# define LOADARGS_1 \ - "bpushl .L__X'%k3, %k3\n\t" -# define LOADARGS_5 \ - "movl %%ebx, %4\n\t" \ - "movl %3, %%ebx\n\t" -# else -# define LOADARGS_1 \ - "bpushl .L__X'%k2, %k2\n\t" -# define LOADARGS_5 \ - "movl %%ebx, %3\n\t" \ - "movl %2, %%ebx\n\t" -# endif -# define LOADARGS_2 LOADARGS_1 -# define LOADARGS_3 \ - "xchgl %%ebx, %%edi\n\t" -# define LOADARGS_4 LOADARGS_3 -#else -# define LOADARGS_1 -# define LOADARGS_2 -# define LOADARGS_3 -# define LOADARGS_4 -# define LOADARGS_5 -#endif - -#define RESTOREARGS_0 -#ifdef __PIC__ -# if I386_USE_SYSENTER && defined PIC -# define RESTOREARGS_1 \ - "bpopl .L__X'%k3, %k3\n\t" -# define RESTOREARGS_5 \ - "movl %4, %%ebx" -# else -# define RESTOREARGS_1 \ - "bpopl .L__X'%k2, %k2\n\t" -# define RESTOREARGS_5 \ - "movl %3, %%ebx" -# endif -# define RESTOREARGS_2 RESTOREARGS_1 -# define RESTOREARGS_3 \ - "xchgl %%edi, %%ebx\n\t" -# define RESTOREARGS_4 RESTOREARGS_3 -#else -# define RESTOREARGS_1 -# define RESTOREARGS_2 -# define RESTOREARGS_3 -# define RESTOREARGS_4 -# define RESTOREARGS_5 -#endif - -#ifdef OPTIMIZE_FOR_GCC_5 -# define LOADREGS_0() -# define ASMARGS_0() -# define LOADREGS_1(arg1) \ +#define LOADREGS_0() +#define ASMARGS_0() +#define LOADREGS_1(arg1) \ LOADREGS_0 () -# define ASMARGS_1(arg1) \ +#define ASMARGS_1(arg1) \ ASMARGS_0 (), "b" ((unsigned int) (arg1)) -# define LOADREGS_2(arg1, arg2) \ +#define LOADREGS_2(arg1, arg2) \ LOADREGS_1 (arg1) -# define ASMARGS_2(arg1, arg2) \ +#define ASMARGS_2(arg1, arg2) \ ASMARGS_1 (arg1), "c" ((unsigned int) (arg2)) -# define LOADREGS_3(arg1, arg2, arg3) \ +#define LOADREGS_3(arg1, arg2, arg3) \ LOADREGS_2 (arg1, arg2) -# define ASMARGS_3(arg1, arg2, arg3) \ +#define ASMARGS_3(arg1, arg2, arg3) \ ASMARGS_2 (arg1, arg2), "d" ((unsigned int) (arg3)) -# define LOADREGS_4(arg1, arg2, arg3, arg4) \ +#define LOADREGS_4(arg1, arg2, arg3, arg4) \ LOADREGS_3 (arg1, arg2, arg3) -# define ASMARGS_4(arg1, arg2, arg3, arg4) \ +#define ASMARGS_4(arg1, arg2, arg3, arg4) \ ASMARGS_3 (arg1, arg2, arg3), "S" ((unsigned int) (arg4)) -# define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \ +#define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \ LOADREGS_4 (arg1, arg2, arg3, arg4) -# define ASMARGS_5(arg1, arg2, arg3, arg4, arg5) \ +#define ASMARGS_5(arg1, arg2, arg3, arg4, arg5) \ ASMARGS_4 (arg1, arg2, arg3, arg4), "D" ((unsigned int) (arg5)) + +#ifdef OPTIMIZE_FOR_GCC_5 # define LOADREGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \ register unsigned int _a6 asm ("ebp") = (unsigned int) (arg6); \ LOADREGS_5 (arg1, arg2, arg3, arg4, arg5)