From patchwork Sat May 24 03:02:33 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 1131 Received: (qmail 26021 invoked by alias); 24 May 2014 03:02:49 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 25991 invoked by uid 89); 24 May 2014 03:02:46 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL, BAYES_00, FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=no version=3.3.2 X-HELO: mail-qg0-f42.google.com X-Received: by 10.224.129.66 with SMTP id n2mr12733706qas.55.1400900563628; Fri, 23 May 2014 20:02:43 -0700 (PDT) From: Richard Henderson To: libc-alpha@sourceware.org Cc: roland@hack.frob.com Subject: [PATCH v2 1/2] Only support ifunc in nptl/pt-vfork.c Date: Fri, 23 May 2014 20:02:33 -0700 Message-Id: <1400900554-5347-2-git-send-email-rth@twiddle.net> In-Reply-To: <1400900554-5347-1-git-send-email-rth@twiddle.net> References: <1400900554-5347-1-git-send-email-rth@twiddle.net> * nptl/pt-vfork.c: Error if !HAVE_IFUNC. [!HAVE_IFUNC] (vfork_compat): Remove. [!HAVE_IFUNC] (DEFINE_VFORK): Remove. --- nptl/pt-vfork.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/nptl/pt-vfork.c b/nptl/pt-vfork.c index 81d1b71..eaffe48 100644 --- a/nptl/pt-vfork.c +++ b/nptl/pt-vfork.c @@ -28,13 +28,24 @@ vfork symbols in libpthread.so; so we define them using IFUNC to redirect to the libc function. */ +/* Note! If the architecture doesn't support IFUNC, then we need an + alternate target-specific mechanism to implement this. So we just + assume IFUNC here and require that the target override this file + if necessary. + + If the architecture can assume all supported versions of gcc will + produce a tail-call to __libc_vfork, consider including the version + in sysdeps/unix/sysv/linux/aarch64/pt-vfork.c. */ + +#if !HAVE_IFUNC +# error "must write pt-vfork for this machine or get IFUNC support" +#endif + #if (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \ || SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)) extern __typeof (vfork) __libc_vfork; /* Defined in libc. */ -# ifdef HAVE_IFUNC - attribute_hidden __attribute__ ((used)) __typeof (vfork) * vfork_ifunc (void) @@ -42,29 +53,16 @@ vfork_ifunc (void) return &__libc_vfork; } -# ifdef HAVE_ASM_SET_DIRECTIVE -# define DEFINE_VFORK(name) \ +# ifdef HAVE_ASM_SET_DIRECTIVE +# define DEFINE_VFORK(name) \ asm (".set " #name ", vfork_ifunc\n" \ ".globl " #name "\n" \ ".type " #name ", %gnu_indirect_function"); -# else -# define DEFINE_VFORK(name) \ +# else +# define DEFINE_VFORK(name) \ asm (#name " = vfork_ifunc\n" \ ".globl " #name "\n" \ ".type " #name ", %gnu_indirect_function"); -# endif - -# else - -attribute_hidden -pid_t -vfork_compat (void) -{ - return __libc_vfork (); -} - -# define DEFINE_VFORK(name) weak_alias (vfork_compat, name) - # endif #endif