From 250c40799dd5e3bf1d7ebead8ddd894b8cb8c528 Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Sat, 19 May 2012 04:13:47 -0700 Subject: [PATCH] Syscalls: warn when the length argument to mmap is excessive. If the length argument to mmap is larger than the arbitrary but reasonable limit of 4GB, there's a good chance that the value is nonsense and not intentional. Rather than attempting to satisfy the mmap anyway, this change makes gem5 warn to make it more apparent what's going wrong. --- src/sim/syscall_emul.hh | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh index 504add35f..87899abca 100644 --- a/src/sim/syscall_emul.hh +++ b/src/sim/syscall_emul.hh @@ -1004,6 +1004,9 @@ mmapFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc) int tgt_fd = p->getSyscallArg(tc, index); // int offset = p->getSyscallArg(tc, index); + if (length > 0x100000000ULL) + warn("mmap length argument %#x is unreasonably large.\n", length); + if (!(flags & OS::TGT_MAP_ANONYMOUS)) { Process::FdMap *fd_map = p->sim_fd_obj(tgt_fd); if (!fd_map || fd_map->fd < 0) { -- 2.30.2