On Mon, Mar 15, 2010 at 04:08:46PM +0100, Jan-Simon Möller wrote: > Am Montag, 15. März 2010 15:48:03 schrieb Riku Voipio: > > On Mon, Mar 15, 2010 at 01:46:10PM +0100, Jan-Simon Möller wrote: > > > r...@frodo:/# qemu-arm -strace /sbin/ldconfig.real > > > 16359 uname(0x403fef78) = 0 > > > 16359 brk(NULL) = 0x000a9000 > > > 16359 brk(0x000a9d08) = 0x000a9d08 > > > 16359 open("/dev/urandom",O_RDONLY) = 3 > > > 16359 read(3,0x403ff27d,3) = 3 > > > 16359 close(3) = 0 > > > [...] > > > 16359 stat64("/usr/lib/libgettextlib.so",0x403fdf28) = 0 > > > 16359 stat64("/usr/lib/libgettextpo.so.0",0x403fdec0) = 0 > > > 16359 stat64("/usr/lib/libgettextpo.so.0.4.0",0x403fdf28) = 0 > > > 16359 stat64("/usr/lib/libpython2.6.so.1.0",0x403fdec0) = 0 > > > 16359 stat64("/usr/lib/libpython2.6.so.1.0",0x403fdf28) = 0 > > > 16359 open("/etc/ld.so.cache~",O_WRONLY|O_CREAT|O_NOFOLLOW|O_TRUNC,0600) > > > = 3 16359 write(3,0xb03d0,1288) = 1288 > > > 16359 write(3,0x403ff0a0,0) = -1 errno=14 (Bad address) > > A zero sized write. According to manpage ok. > > In qemu we do a lock_user to to get the string to write. Richards change > > changes the access checks the get called by lock_user:
> > page_check_range: > > > > - if (start + len < start) > > - /* we've wrapped around */ > > ... > > + if (start + len - 1 < start) { > > + /* We've wrapped around. */ > > > > This now blows up with len = 0; > Confirmed. A quick test with if (len > 0) around and ldconfig.real runs. Richard, would you be ok with that change? Or should we rather have explicit if (len == 0) return 0; ?