cvs commit: src/sys/kern imgact_elf.c vfs_lookup.c
jhb at FreeBSD.org
Thu Sep 15 08:29:59 PDT 2005
On Thursday 15 September 2005 11:03 am, Christian S.J. Peron wrote:
> csjp 2005-09-15 15:03:48 UTC
> FreeBSD src repository
> Modified files:
> sys/kern imgact_elf.c vfs_lookup.c vfs_syscalls.c
> 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
> 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
Why not just use mtx_assert() to do locking assertions?
if (!(cnp->cn_flags & MPSAFE))
Also, note that assertions only depend on INVARIANTS, not on WITNESS.
John Baldwin <jhb at FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve" = http://www.FreeBSD.org
More information about the cvs-src