From patchwork Fri Apr 6 16:35:10 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Riku Voipio X-Patchwork-Id: 151250 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 81266B7097 for ; Sat, 7 Apr 2012 05:06:10 +1000 (EST) Received: from localhost ([::1]:58473 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SGEU4-0005hs-8x for incoming@patchwork.ozlabs.org; Fri, 06 Apr 2012 15:06:08 -0400 Received: from eggs.gnu.org ([208.118.235.92]:52279) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SGCE0-0003Ds-4I for qemu-devel@nongnu.org; Fri, 06 Apr 2012 12:41:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SGCDv-00069g-S9 for qemu-devel@nongnu.org; Fri, 06 Apr 2012 12:41:23 -0400 Received: from afflict.kos.to ([92.243.29.197]:59850) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SGC89-0004wg-SZ for qemu-devel@nongnu.org; Fri, 06 Apr 2012 12:35:22 -0400 Received: by afflict.kos.to (Postfix, from userid 1000) id DA37B2653B; Fri, 6 Apr 2012 16:35:17 +0000 (UTC) From: riku.voipio@linaro.org To: qemu-devel@nongnu.org Date: Fri, 6 Apr 2012 19:35:10 +0300 Message-Id: <59e9d91c7ae1b655997aec61c08eec1685414117.1333729958.git.riku.voipio@linaro.org> X-Mailer: git-send-email 1.7.1 In-Reply-To: References: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 92.243.29.197 X-Mailman-Approved-At: Fri, 06 Apr 2012 15:05:48 -0400 Cc: Peter Maydell Subject: [Qemu-devel] [PATCH 10/17] linux-user: resolve reserved_va vma downwards X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Peter Maydell After consulting with Paul Brook, we concluded that it's best to search the VMA space downwards, so that we don't even get the chance to conflict with the brk range. This patch resolves a bunch of allocation conflicts when using -R. Signed-off-by: Alexander Graf [minor changes to get it to apply -- PMM] Signed-off-by: Riku Voipio --- linux-user/main.c | 1 + linux-user/mmap.c | 35 ++++++++++++++++++++++++----------- linux-user/qemu.h | 1 + 3 files changed, 26 insertions(+), 11 deletions(-) diff --git a/linux-user/main.c b/linux-user/main.c index 2570140..aa95db3 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -3420,6 +3420,7 @@ int main(int argc, char **argv, char **envp) guest_base = HOST_PAGE_ALIGN((unsigned long)p); } qemu_log("Reserved 0x%lx bytes of guest address space\n", reserved_va); + mmap_next_start = reserved_va; } if (reserved_va || have_guest_base) { diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 994c02b..7125d1c 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -212,7 +212,7 @@ static int mmap_frag(abi_ulong real_start, #else # define TASK_UNMAPPED_BASE 0x40000000 #endif -static abi_ulong mmap_next_start = TASK_UNMAPPED_BASE; +abi_ulong mmap_next_start = TASK_UNMAPPED_BASE; unsigned long last_brk; @@ -222,7 +222,7 @@ unsigned long last_brk; static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size) { abi_ulong addr; - abi_ulong last_addr; + abi_ulong end_addr; int prot; int looped = 0; @@ -230,25 +230,38 @@ static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size) return (abi_ulong)-1; } - last_addr = start; - for (addr = start; last_addr + size != addr; addr += qemu_host_page_size) { - if (last_addr + size >= RESERVED_VA - || (abi_ulong)(last_addr + size) < last_addr) { + size = HOST_PAGE_ALIGN(size); + end_addr = start + size; + if (end_addr > RESERVED_VA) { + end_addr = RESERVED_VA; + } + addr = end_addr - qemu_host_page_size; + + while (1) { + if (addr > end_addr) { if (looped) { return (abi_ulong)-1; } - last_addr = qemu_host_page_size; - addr = 0; + end_addr = RESERVED_VA; + addr = end_addr - qemu_host_page_size; looped = 1; continue; } prot = page_get_flags(addr); if (prot) { - last_addr = addr + qemu_host_page_size; + end_addr = addr; + } + if (addr + size == end_addr) { + break; } + addr -= qemu_host_page_size; + } + + if (start == mmap_next_start) { + mmap_next_start = addr; } - mmap_next_start = addr; - return last_addr; + + return addr; } #endif diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 6889567..dd74cc0 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -251,6 +251,7 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, abi_ulong new_addr); int target_msync(abi_ulong start, abi_ulong len, int flags); extern unsigned long last_brk; +extern abi_ulong mmap_next_start; void mmap_lock(void); void mmap_unlock(void); abi_ulong mmap_find_vma(abi_ulong, abi_ulong);