From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1792) id 24E813858412; Sun, 2 Jul 2023 23:38:24 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 24E813858412 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1688341104; bh=XsQdXJq6qOCfaXxMcCb+A6dQFFQ/7yEWLvlIPuucWpQ=; h=From:To:Subject:Date:From; b=GurXRsMcp/gfavCxoVyQ2iMzd9f09eygDVOGFeDUjlYtIOGNuw104y1zyrPy4ZCc9 K1Xqd27yESLOnZQA6QNcI3btc+Wc+3ZlxzhSLUdfK6KhxuXQTOLPNdlSfo8+ko/Es0 qTqCbanJmsV169rNBXGuzfXDDOUv54yhg4SirlJI= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Samuel Thibault To: glibc-cvs@sourceware.org Subject: [glibc] htl: Let Mach place thread stacks X-Act-Checkin: glibc X-Git-Author: Sergey Bugaev X-Git-Refname: refs/heads/master X-Git-Oldrev: efdb85183aca7634d61a413c55d63e519d89d162 X-Git-Newrev: 019b0bbc84e2048556ac1a6b6df3a61e45fc1e17 Message-Id: <20230702233824.24E813858412@sourceware.org> Date: Sun, 2 Jul 2023 23:38:24 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=019b0bbc84e2048556ac1a6b6df3a61e45fc1e17 commit 019b0bbc84e2048556ac1a6b6df3a61e45fc1e17 Author: Sergey Bugaev Date: Mon Jun 26 02:17:47 2023 +0300 htl: Let Mach place thread stacks Instead of trying to allocate a thread stack at a specific address, looping over the address space, just set the ANYWHERE flag in vm_allocate (). The previous behavior: - defeats ASLR (for Mach versions that support ASLR), - is particularly slow if the lower 4 GB of the address space are mapped inaccessible, as we're planning to do on 64-bit Hurd, - is just silly. Signed-off-by: Sergey Bugaev Message-Id: <20230625231751.404120-1-bugaevc@gmail.com> Diff: --- sysdeps/mach/htl/pt-stack-alloc.c | 35 ++++++----------------------------- 1 file changed, 6 insertions(+), 29 deletions(-) diff --git a/sysdeps/mach/htl/pt-stack-alloc.c b/sysdeps/mach/htl/pt-stack-alloc.c index 429ac2d9f7..97e6b4455b 100644 --- a/sysdeps/mach/htl/pt-stack-alloc.c +++ b/sysdeps/mach/htl/pt-stack-alloc.c @@ -19,14 +19,9 @@ #include #include -#include #include -/* The next address to use for stack allocation. */ -static vm_address_t next_stack_base = VM_MIN_ADDRESS; - - /* Allocate a new stack of size STACKSIZE. If successful, store the address of the newly allocated stack in *STACKADDR and return 0. Otherwise return an error code (EINVAL for an invalid stack size, @@ -35,30 +30,12 @@ static vm_address_t next_stack_base = VM_MIN_ADDRESS; int __pthread_stack_alloc (void **stackaddr, size_t stacksize) { - vm_offset_t base; - int i = 0; - -get_stack: - i++; - for (base = next_stack_base; - base < VM_MAX_ADDRESS - && __vm_allocate (__mach_task_self (), &base, - stacksize, FALSE) != KERN_SUCCESS; base += stacksize) - ; - - if (base >= VM_MAX_ADDRESS) - { - if (i == 1) - { - next_stack_base = VM_MIN_ADDRESS; - goto get_stack; - } - else - return EAGAIN; - } + error_t err; - next_stack_base = base + stacksize; + err = __vm_allocate (__mach_task_self (), (vm_offset_t *) stackaddr, + stacksize, TRUE); - (*stackaddr) = (void *) base; - return 0; + if (err == KERN_NO_SPACE) + err = EAGAIN; + return err; }