Linux allows to mmap annonymous with a file descriptor passed, FreeBSD

doesn't.  In the Linux emulation layer, ignore the fd passed when
MAP_ANON is specified.

Known application to be fixed: Xanalys/Harlequin Lispworks

Also improve debug output for mmap, now showing what the emulation
layer mapped to what (-DDEBUG).

Reviewed by:	marcel

1 files changed, 10 insertions, 2 deletions

diff --git a/sys/compat/linux/linux_misc.c b/sys/compat/linux/linux_misc.c
index bb043e4..1adea54 100644
--- a/sys/compat/linux/linux_misc.c
+++ b/sys/compat/linux/linux_misc.c
@@ -696,7 +696,7 @@ linux_mmap(struct proc *p, struct linux_mmap_args *args)
 			sizeof(linux_args))))
 	return error;
 #ifdef DEBUG
-    printf("Linux-emul(%ld): mmap(%p, %d, %d, %08x, %d, %d)\n",
+    printf("Linux-emul(%ld): mmap(%p, %d, %d, 0x%08x, %d, %d)",
 	(long)p->p_pid, (void *)linux_args.addr, linux_args.len,
 	linux_args.prot, linux_args.flags, linux_args.fd, linux_args.pos);
 #endif
@@ -756,9 +756,17 @@ linux_mmap(struct proc *p, struct linux_mmap_args *args)
     }
 
     bsd_args.prot = linux_args.prot | PROT_READ;	/* always required */
-    bsd_args.fd = linux_args.fd;
+    if (linux_args.flags & LINUX_MAP_ANON)
+	bsd_args.fd = -1;
+    else
+	bsd_args.fd = linux_args.fd;
     bsd_args.pos = linux_args.pos;
     bsd_args.pad = 0;
+#ifdef DEBUG
+    printf("-> (%p, %d, %d, 0x%08x, %d, %d)\n",
+	(void *)bsd_args.addr, bsd_args.len,
+	bsd_args.prot, bsd_args.flags, bsd_args.fd, (int)bsd_args.pos);
+#endif
     return mmap(p, &bsd_args);
 }