I've been using PAM 0.75 since I installed Linux From Scratch on one of my workstation, and recently tried to upgrade gdm (>=2.2.4.0) since it has nested servers feature. However, PAM refuses to "setcred" for gdm login. With some digging up the source codes what I found was that gdm now separated authentification and open session w/ setcred in different functions with some reasons related to setgid, etc. I tried to make a simple program mimicking the structure of gdm w/ some sample codes in the PAM sources: The main point is the first routine containing authentification ends with pam_end call. Now this program promtly failed at the second function which tried to setcred after pam_start call. The error code was 6 (I think it is NO PERMISSION?) I ran this program on a RH 7.1 which use PAM 0.74, and it succeeded. I downgraded my PAM installation on the LFS machine to 0.74, and the program works. So my conclusion is that PAM 0.74 does some kind of memory preservation or disk cache, but 0.75 doesn't. I post this problem in gdm bug list, it seems the responder doesn't have much clue on the internal working of PAM nor experience with 0.75. Does anybody have an idea how to solve this problem? If my assessment is correct, many distros will encounter this problem when they want to upgrade Gnome and PAM at the same time... Regards.
