On Thu, Jul 23, 2015 at 02:24:40PM -0700, Alex Gartrell wrote: > mov %rsp, %r1 ; r1 = rsp > add $-8, %r1 ; r1 = rsp - 8 > store_q $123, -8(%rsp) ; *(u64*)r1 = 123 <- valid > store_q $123, (%r1) ; *(u64*)r1 = 123 <- previously invalid > mov $0, %r0 > exit ; Always need to exit > > And we'd get the following error: > > 0: (bf) r1 = r10 > 1: (07) r1 += -8 > 2: (7a) *(u64 *)(r10 -8) = 999 > 3: (7a) *(u64 *)(r1 +0) = 999 > R1 invalid mem access 'fp' > > Unable to load program > > We already know that a register is a stack address and the appropriate > offset, so we should be able to validate those references as well. > > Signed-off-by: Alex Gartrell <agartr...@fb.com> > --- > kernel/bpf/verifier.c | 6 ++++- > samples/bpf/test_verifier.c | 59 > +++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 64 insertions(+), 1 deletion(-)
Looks good. Acked-by: Alexei Starovoitov <a...@plumgrid.com> > + BPF_ST_MEM(BPF_DW, BPF_REG_1, 2, 0xfaceb00c), nice constants :) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
