Hi folks, I've got an odd regression with the v4.2 rc kernel, and I wondered if anyone else could reproduce it.
The problem occurs with a seccomp-bpf filter program that's set up to return an errno value -- an errno of 1 is always returned instead of what's in the filter, plus other oddities (selftest output below). The problem seems to need a combination of circumstances to occur: - The seccomp-bpf userspace program needs to be 32-bit, running against a 64-bit kernel -- I'm testing with seccomp_bpf from tools/testing/selftests/seccomp/, built via 'CFLAGS=-m32 make'. - The kernel needs to be running as a VM guest -- it occurs inside my VMware Fusion host, but not if I run on bare metal. Kees tells me he cannot repro with a kvm guest though. Bisecting indicates that the commit that induces the problem is 3f5159a9221f19b0, "x86/asm/entry/32: Update -ENOSYS handling to match the 64-bit logic", included in all the v4.2-rc* candidates. Apologies if I've just got something odd with my local setup, but the bisection was unequivocal enough that I thought it worth reporting... Thanks, David seccomp_bpf failure outputs: seccomp_bpf.c:533:global.ERRNO_valid:Expected 7 (7) == (*__errno_location ()) (1) seccomp_bpf.c:560:global.ERRNO_zero:Expected 0 (0) == read(0, ((void *)0), 0) (4294967295) seccomp_bpf.c:587:global.ERRNO_capped:Expected 4095 (4095) == (*__errno_location ()) (1) seccomp_bpf.c:905:precedence.errno_is_third:Expected 0 (0) == syscall(20) (4294967295) seccomp_bpf.c:925:precedence.errno_is_third_in_any_order:Expected 0 (0) == syscall(20) (4294967295) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
