From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-il1-x12c.google.com (mail-il1-x12c.google.com [IPv6:2607:f8b0:4864:20::12c]) by sourceware.org (Postfix) with ESMTPS id AF882388883F for ; Tue, 15 Jun 2021 19:29:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AF882388883F Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=moxielogic.com Authentication-Results: sourceware.org; spf=none smtp.mailfrom=moxielogic.com Received: by mail-il1-x12c.google.com with SMTP id i17so116448ilj.11 for ; Tue, 15 Jun 2021 12:29:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=moxielogic-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RwCTPf8VuKUbzTfMpYO7KRh7isULwwUF2R/6jAI2aWU=; b=Ga5SH3fYGRXhVMkJ7TAmYmrxSjB91dJ0v6tLyHbfKyUXh8aRK7vDJWvzVHsyYkDp6q oemwzhT4kSXCnbxqGNgOh4OPJ6tIdiIuzQBo9GVM8UJrJNWgE9nwmbdEJgdYsNOtRehM z/Ugtn9GjNsDn/ks9zYBID1zcpTEOjGKI8d4kObBdCiDh6gqGK0gtT4Ml1p3SohgPR5m 7aye0e9jG7496pu7x6TdN6EcCMweGNfIRagBld0lWWJEd/hM6NgsfoILvJ/ENQ+OtqrX 5/SvBVR+v8gNwD9lBhgg0hKlqDS4WbkhWJ/3iOd5UZ5QKtgTR/CFos6G5f/1fHpIXu6u aMgQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RwCTPf8VuKUbzTfMpYO7KRh7isULwwUF2R/6jAI2aWU=; b=YQGNqHQ4pQRVfvMQtmim/nYL5nlkRhnXYiY+dAuLeIFXree9xiKAEEf4cTQtdN4+7o rjURwPCuZEM/6IVnRL7qha730c0xUb4g+Vk+zhUfJwGZykCaN1+n1y9WNCOYysmsvfne 77jUyXW7P4SnST8/zANzCXCFr6DKe0WiIv8Ju7te3bwTsUUMfbp/KnyckBxKlzWenzD+ ZpSvUK3Mtk/g/Dj2TJLDyTpVbKfm/gVYBh9jsE1daTbAuMStgOve76WROgjuxMR3Zl8c yFyr8YtDnYTr9Ne5fS9mcHVO8iyJR2AWzPuhMxLQ408tbxngPCqpLMjSztpYXjGR/DZV HJVg== X-Gm-Message-State: AOAM532QBWHnkRjhw0yiZJv6FI5OlZQOvOK5H9JlcwVdUXzgdJERyQDd NTkHUGdbTGqMXqKCazjO/z3Xn01D4P88qmcSHL5hWGOqrLTqrQ== X-Google-Smtp-Source: ABdhPJwc5vbjNcWyqZk21n4rc5tPyJ4bMeF22oZiMMHEokylfvBdqhbuXOPw1f2mHjWN2yg5YXdiNKTRpS0t8jNt30Y= X-Received: by 2002:a05:6e02:1a6a:: with SMTP id w10mr807017ilv.130.1623785396886; Tue, 15 Jun 2021 12:29:56 -0700 (PDT) MIME-Version: 1.0 References: <20210615180256.GQ7746@tucnak> <20210615190200.GR7746@tucnak> In-Reply-To: <20210615190200.GR7746@tucnak> From: Anthony Green Date: Tue, 15 Jun 2021 15:29:46 -0400 Message-ID: Subject: Re: Incorrect data detected in the nested float struct with x86/libffi on Linux/64bit To: Jakub Jelinek Cc: libffi-discuss X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, HTML_MESSAGE, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: libffi-discuss@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libffi-discuss mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Jun 2021 19:30:01 -0000 Thank you, Jakub! This has been committed. AG On Tue, Jun 15, 2021 at 3:02 PM Jakub Jelinek wrote: > On Tue, Jun 15, 2021 at 08:02:56PM +0200, Jakub Jelinek via Libffi-discuss > wrote: > > On Wed, Jun 09, 2021 at 12:50:08PM -0400, Anthony Green wrote: > > > Thank you, Cheng. Are you able to submit this test case as a github > pull > > > request? The resulting CI testing will give us a broader picture of > where > > > we have problems. > > > > Comparing gcc/config/i386/ classify_argument and libffi > classify_argument, > > I found two important differences. > > > > The first one seems the most important one, even GCC 3.2 included the bit > > offset (byte offset in libffi) in the calculation of number of words. > > And the other change is https://gcc.gnu.org/PR38781. > > > > With this patch the posted testcase works and the testsuite on > x86_64-linux > > still passes, but haven't done more testing than that. > > > > Haven't tried yet to adapt one of the > > libffi/testsuite/libffi.call/nested_struct*.c tests to cover this though. > > And here is one with a testcase (modified nested_struct2.c for it). > > I'm unsure about the current relationship between the github and gcc > copy of libffi, shall it go to both, or just one of them and be > cherry-picked from there? > > Tested on x86_64-linux. > > 2021-06-15 Jakub Jelinek > > * src/x86/ffi64.c (classify_argument): For FFI_TYPE_STRUCT set > words > to number of words needed for type->size + byte_offset bytes rather > than just type->size bytes. Compute pos before the loop and check > total size of the structure. > * testsuite/libffi.call/nested_struct12.c: New test. > > --- libffi/src/x86/ffi64.c.jj 2020-01-14 20:02:48.557583260 +0100 > +++ libffi/src/x86/ffi64.c 2021-06-15 19:50:06.059108230 +0200 > @@ -217,7 +217,8 @@ classify_argument (ffi_type *type, enum > case FFI_TYPE_STRUCT: > { > const size_t UNITS_PER_WORD = 8; > - size_t words = (type->size + UNITS_PER_WORD - 1) / UNITS_PER_WORD; > + size_t words = (type->size + byte_offset + UNITS_PER_WORD - 1) > + / UNITS_PER_WORD; > ffi_type **ptr; > int i; > enum x86_64_reg_class subclasses[MAX_CLASSES]; > @@ -241,16 +242,16 @@ classify_argument (ffi_type *type, enum > /* Merge the fields of structure. */ > for (ptr = type->elements; *ptr != NULL; ptr++) > { > - size_t num; > + size_t num, pos; > > byte_offset = ALIGN (byte_offset, (*ptr)->alignment); > > num = classify_argument (*ptr, subclasses, byte_offset % 8); > if (num == 0) > return 0; > - for (i = 0; i < num; i++) > + pos = byte_offset / 8; > + for (i = 0; i < num && (i + pos) < words; i++) > { > - size_t pos = byte_offset / 8; > classes[i + pos] = > merge_classes (subclasses[i], classes[i + pos]); > } > --- libffi/testsuite/libffi.call/nested_struct12.c.jj 2021-06-15 > 20:31:43.327144303 +0200 > +++ libffi/testsuite/libffi.call/nested_struct12.c 2021-06-15 > 20:47:13.129489263 +0200 > @@ -0,0 +1,107 @@ > +/* Area: ffi_call, closure_call > + Purpose: Check structure passing. > + Limitations: none. > + PR: none. > + Originator: and 20210609 > */ > + > +/* { dg-do run } */ > +#include "ffitest.h" > + > +typedef struct A { > + float a, b; > +} A; > + > +typedef struct B { > + float x; > + struct A y; > +} B; > + > +B B_fn(float b0, struct B b1) > +{ > + struct B result; > + > + result.x = b0 + b1.x; > + result.y.a = b0 + b1.y.a; > + result.y.b = b0 + b1.y.b; > + > + printf("%g %g %g %g: %g %g %g\n", b0, b1.x, b1.y.a, b1.y.b, > + result.x, result.y.a, result.y.b); > + > + return result; > +} > + > +static void > +B_gn(ffi_cif* cif __UNUSED__, void* resp, void** args, > + void* userdata __UNUSED__) > +{ > + float b0; > + struct B b1; > + > + b0 = *(float*)(args[0]); > + b1 = *(struct B*)(args[1]); > + > + *(B*)resp = B_fn(b0, b1); > +} > + > +int main (void) > +{ > + ffi_cif cif; > + void *code; > + ffi_closure *pcl = ffi_closure_alloc(sizeof(ffi_closure), &code); > + void* args_dbl[3]; > + ffi_type* cls_struct_fields[3]; > + ffi_type* cls_struct_fields1[3]; > + ffi_type cls_struct_type, cls_struct_type1; > + ffi_type* dbl_arg_types[3]; > + > + float e_dbl = 12.125f; > + struct B f_dbl = { 24.75f, { 31.625f, 32.25f } }; > + > + struct B res_dbl; > + > + cls_struct_type.size = 0; > + cls_struct_type.alignment = 0; > + cls_struct_type.type = FFI_TYPE_STRUCT; > + cls_struct_type.elements = cls_struct_fields; > + > + cls_struct_type1.size = 0; > + cls_struct_type1.alignment = 0; > + cls_struct_type1.type = FFI_TYPE_STRUCT; > + cls_struct_type1.elements = cls_struct_fields1; > + > + cls_struct_fields[0] = &ffi_type_float; > + cls_struct_fields[1] = &ffi_type_float; > + cls_struct_fields[2] = NULL; > + > + cls_struct_fields1[0] = &ffi_type_float; > + cls_struct_fields1[1] = &cls_struct_type; > + cls_struct_fields1[2] = NULL; > + > + > + dbl_arg_types[0] = &ffi_type_float; > + dbl_arg_types[1] = &cls_struct_type1; > + dbl_arg_types[2] = NULL; > + > + CHECK(ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 2, &cls_struct_type1, > + dbl_arg_types) == FFI_OK); > + > + args_dbl[0] = &e_dbl; > + args_dbl[1] = &f_dbl; > + args_dbl[2] = NULL; > + > + ffi_call(&cif, FFI_FN(B_fn), &res_dbl, args_dbl); > + /* { dg-output "12.125 24.75 31.625 32.25: 36.875 43.75 44.375" } */ > + CHECK( res_dbl.x == (e_dbl + f_dbl.x)); > + CHECK( res_dbl.y.a == (e_dbl + f_dbl.y.a)); > + CHECK( res_dbl.y.b == (e_dbl + f_dbl.y.b)); > + > + CHECK(ffi_prep_closure_loc(pcl, &cif, B_gn, NULL, code) == FFI_OK); > + > + res_dbl = ((B(*)(float, B))(code))(e_dbl, f_dbl); > + /* { dg-output "\n12.125 24.75 31.625 32.25: 36.875 43.75 44.375" } */ > + CHECK( res_dbl.x == (e_dbl + f_dbl.x)); > + CHECK( res_dbl.y.a == (e_dbl + f_dbl.y.a)); > + CHECK( res_dbl.y.b == (e_dbl + f_dbl.y.b)); > + > + exit(0); > +} > > > Jakub > >