From: Paul H. Hargrove (PHHargrove_at_lbl_dot_gov)
Date: Wed Aug 13 2008 - 10:38:32 PDT
As the manpage says, POSIX and other standards don't specify whether the "base" group is part of the list returned by getgroups(). IIRC, getgroups() under Linux returns exactly the list set by setgroups(), so the difference comes down to user-space tools, like login and/or PAM, that setup your session. So, this is probably a distro-specific difference between the i386 and ARM platforms, not a kernel difference. -Paul mukti jain wrote: > I checked on i386 and arm, > getgroups when run by a user(included in one group only) returns > zero supplementary groups on arm and 1 on i386. > in the manpage of getgroups it is said that > "It is unspecified whether the effective group ID of the calling > process is included in the returned list." > > Can someone throw more light on this? > > On Wed, Aug 13, 2008 at 2:27 PM, mukti jain <muktijn_at_gmail_dot_com > <mailto:muktijn_at_gmail_dot_com>> wrote: > > We have not seen the issue on x86 with the same application, > why is this problem arm specific? > > > On Tue, Aug 12, 2008 at 12:04 AM, Paul H. Hargrove > <PHHargrove_at_lbl_dot_gov <mailto:PHHargrove_at_lbl_dot_gov>> wrote: > > It seems the ENOMEM problem reported by Manish Dwivedi > recently is due to having zero supplementary group ids. > When BLCR goes to save the group ids, this results in > vmalloc(0) which rightly returns NULL. BLCR, however, > interprets the NULL return as an out of memory condition. > Mukti Jain has observed that the same exists on the > corresponding restore path. > > Attached is a patch that should resolve these problems > (works in my limited testing). > > I had planned to release 0.7.3 today, but will probably > delay that until I've gotten confirmation from Manish > and/or Mukti that this patch solves the problem, or until > somebody finds a problem with this patch. > > -Paul > > -- > Paul H. Hargrove > PHHargrove_at_lbl_dot_gov <mailto:PHHargrove_at_lbl_dot_gov> > Future Technologies Group > HPC Research Department Tel: +1-510-495-2352 > Lawrence Berkeley National Laboratory Fax: +1-510-486-6900 > > [snip... patch removed] > > -- Paul H. Hargrove PHHargrove_at_lbl_dot_gov Future Technologies Group HPC Research Department Tel: +1-510-495-2352 Lawrence Berkeley National Laboratory Fax: +1-510-486-6900