On Wednesday, December 20, 2017 10:16:58 AM Nathan Whitehorn wrote: > > On 12/20/17 09:14, John Baldwin wrote: > > On Wednesday, December 20, 2017 09:59:26 AM David Chisnall wrote: > >> On 16 Dec 2017, at 18:05, John Baldwin <j...@freebsd.org> wrote: > >>> When I build a FreeBSD/mips64 kernel with clang, > >>> _any_ simple NFS op triggers a kernel stack overflow. Kernels compiled > >>> with GCC do not. > >> That is not my experience. I haven’t tried a MIPS64 kernel built with > >> clang, but with in-tree gcc I get kernel panics as soon as I try to use > >> NFS, unless I use Stacey’s patches that increase the kernel stack size. > > I have primarily been using modern GCC for GCC once that was working, but at > > least when running a MALTA64 kernel under qemu I was not triggering panics > > even with old GCC. With the in-tree clang 5.0 or with CHERI clang, just > > doing an 'ls' of a NFS directory or even a tab-complete of a path that > > is on NFS reliably triggers a kernel stack overflow for MALTA64 in qemu. > > > > With Stacey's kstack pages, a clang kernel does survive, but those are not > > in stock FreeBSD which is where I have been testing this. > > > > With GCC 4, it takes a little while, but trying to build ports over NFS > is a sure-fire way to bring down the kernel. I haven't tried any other > compilers.
Ah, I have only done things like run binaries over NFS and compile simple test programs over NFS with GCC 4 (I do run a gdb binary over NFS against itself which probably involves a bit of I/O due to debug symbols, etc. but still not as onerous as building lots of ports. I cross-build the GDB on the host due to qemu being too slow). clang insta-panics for even trivial things like 'ls' and tab-completion though. It's definitely much worse than either version of GCC. -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
