I did some research and found that this bug is present since 2003: - 2003/05/13: https://github.com/qemu/qemu/commit/54936004fddc52c321cb3f9a9a51140e782bed5d#diff-2bf4728e0473404c39c97190bd02b2f8 - https://github.com/qemu/qemu/blob/54936004fddc52c321cb3f9a9a51140e782bed5d/linux-user/mmap.c#L182-L183 - 2008/06/02: https://github.com/qemu/qemu/commit/c8a706fe6242a553960ccc3071a4e75ceba6f3d2#diff-2bf4728e0473404c39c97190bd02b2f8 - https://github.com/qemu/qemu/blob/c8a706fe6242a553960ccc3071a4e75ceba6f3d2/linux-user/mmap.c#L284-L285 - https://github.com/qemu/qemu/blob/c8a706fe6242a553960ccc3071a4e75ceba6f3d2/linux-user/mmap.c#L400-L410
It is present in versions 2.11.2, 2.12.0 and master: - https://github.com/qemu/qemu/blob/v2.11.2/linux-user/mmap.c#L401-L402 - https://github.com/qemu/qemu/blob/v2.12.0/linux-user/mmap.c#L401-L402 - https://github.com/qemu/qemu/blob/master/linux-user/mmap.c#L400-L401 I think that a possible fix is: @@ -397,8 +397,10 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, } len = TARGET_PAGE_ALIGN(len); - if (len == 0) - goto the_end; + if (len == 0) { + errno = EINVAL; + goto fail; + } real_start = start & qemu_host_page_mask; host_offset = offset & qemu_host_page_mask; -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1783362 Title: qemu-user-aarch64: mmap returns success (NULL, 0) instead of failure (MAP_FAILED, -1) with len==0 Status in QEMU: New Status in qemu package in Ubuntu: New Bug description: As shown in https://github.com/beehive- lab/mambo/issues/19#issuecomment-407420602, with len==0 mmap returns success (NULL, 0) instead of failure (MAP_FAILED, -1) in a x86_64 host executing a ELF 64-bit LSB executable, ARM aarch64 binary. Steps to reproduce the bug: - (cross-)compile the attached source file: $ aarch64-linux-gnu-gcc -static -std=gnu99 -lpthread test/mmap_qemu.c -o mmap_qemu - Execute in a x86_64 host with qemu-user and qemu-user-binfmt: $ ./mmap_qemu alloc: 0 MAP_FAILED: -1 errno: 0 mmap_qemu: test/mmap_qemu.c:15: main: Assertion `alloc == MAP_FAILED' failed. qemu: uncaught target signal 6 (Aborted) - core dumped Aborted (core dumped) - Execute in a ARM host without any additional dependecy: $ ./mmap_qemu alloc: -1 MAP_FAILED: -1 errno: 22 The bug is present in Fedora: $ qemu-aarch64 --version qemu-aarch64 version 2.11.2(qemu-2.11.2-1.fc28) Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers $ uname -r 4.17.7-200.fc28.x86_64 And also in Ubuntu: $ qemu-aarch64 --version qemu-aarch64 version 2.12.0 (Debian 1:2.12+dfsg-3ubuntu3) Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers $ uname -r 4.15.0-23-generic Possibly related to: - https://lists.freebsd.org/pipermail/freebsd-hackers/2009-July/029109.html - https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=203852 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1783362/+subscriptions
