Date: Thu, 15 Sep 2005 11:30:58 -0400 From: John Baldwin <jhb@FreeBSD.org> To: "Christian S.J. Peron" <csjp@FreeBSD.org> Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern imgact_elf.c vfs_lookup.c vfs_syscalls.c Message-ID: <200509151131.00450.jhb@FreeBSD.org> In-Reply-To: <200509151503.j8FF3m5i086438@repoman.freebsd.org> References: <200509151503.j8FF3m5i086438@repoman.freebsd.org>
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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 > 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 Why not just use mtx_assert() to do locking assertions? if (!(cnp->cn_flags & MPSAFE)) mtx_assert(&Giant, MA_OWNED); Also, note that assertions only depend on INVARIANTS, not on WITNESS. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org
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