Okay, let's tackle this. The user is reporting a bug in QEMU-user related to how it handles the MADV_DONTNEED flag in the madvise syscall. The code in QEMU has a comment saying it's okay to ignore this hint, but the user argues that according to the Linux man pages, MADV_DONTNEED does affect memory semantics, specifically that after the call, accessing the memory should result in zero-filled pages for private mappings. The test case shows that when running under QEMU, the assertion fails because the memory isn't cleared, but it works on native Linux. So the issue is that QEMU's user-mode emulation is not properly handling the MADV_DONTNEED advice. The problem is in the syscall handling because the madvise system call is being processed incorrectly. The comment in the code treats it as a hint and ignores it, but the actual Linux behavior requires that the memory be invalidated in a way that affects subsequent accesses. Since the application relies on this behavior and QEMU isn't emulating it correctly, this is a syscall-related issue. The error occurs during the execution of the syscall, leading to incorrect program behavior. Therefore, the category should be syscall. syscall