For some reasons ls -l /proc/$$/exe doesnt work all time for me,
with 2.6.8.1 on ppc64. Sometimes it does, sometimes not. No pattern.
A few printks show that this check in proc_pid_readlink() triggers
an -EACCES:

	current->fsuid != inode->i_uid

proc_pid_readlink(755) error -13 ntptrace(11408) fsuid 100 i_uid 0 0
sys_readlink(281) ntptrace(11408) error -13 readlink
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>