cvs commit: src/sys/kern imgact_elf.c vfs_lookup.c vfs_syscalls.c

[Christian S.J. Peron]

csjp        2005-09-15 15:03:48 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             imgact_elf.c vfs_lookup.c vfs_syscalls.c 
  Log:
  Improve the MP safeness associated with the creation of symbolic
  links and the execution of ELF binaries. Two problems were found:
  
  1) The link path wasn't tagged as being MP safe and thus was not properly
     protected.
  2) The ELF interpreter vnode wasnt being locked in namei(9) and thus was
     insufficiently protected.
  
  This commit makes the following changes:
  
  -Sets the MPSAFE flag in NDINIT for symbolic link paths
  -Sets the MPSAFE flag in NDINIT and introduce a vfslocked variable which
   will be used to instruct VFS_UNLOCK_GIANT to unlock Giant if it has been
   picked up.
  -Drop in an assertion into vfs_lookup which ensures that if the MPSAFE
   flag is NOT set, that we have picked up giant. If not panic (if WITNESS
   compiled into the kernel). This should help us find conditions where vnode
   operations are in-sufficiently protected.
  
  This is a RELENG_6 candidate.
  
  Discussed with: jeff
  MFC after:      4 days
  
  Revision  Changes    Path
  1.163     +7 -3      src/sys/kern/imgact_elf.c
  1.82      +2 -0      src/sys/kern/vfs_lookup.c
  1.394     +1 -1      src/sys/kern/vfs_syscalls.c