Commit 92956786 authored May 06, 2024 by Cupertino Miranda Committed by Alexei Starovoitov May 06, 2024

selftests/bpf: MUL range computation tests.



Added a test for bound computation in MUL when non constant
values are used and both registers have bounded ranges.

Signed-off-by: Cupertino Miranda <cupertino.miranda@oracle.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: David Faust <david.faust@oracle.com>
Cc: Jose Marchesi <jose.marchesi@oracle.com>
Cc: Elena Zannoni <elena.zannoni@oracle.com>
Link: https://lore.kernel.org/r/20240506141849.185293-7-cupertino.miranda@oracle.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>

parent 41d047a8

tools/testing/selftests/bpf/progs/verifier_bounds.c

+21 −0

Original line number	Diff line number	Diff line
		@@ -927,6 +927,27 @@ __naked void non_const_or_src_dst(void)
		: __clobber_all);
		}

		SEC("socket")
		__description("bounds check for non const mul regs")
		__success __log_level(2)
		__msg("5: (2f) r0 *= r6 ; R0_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=3825,var_off=(0x0; 0xfff))")
		__naked void non_const_mul_regs(void)
		{
		asm volatile (" \
		call %[bpf_get_prandom_u32]; \
		r6 = r0; \
		call %[bpf_get_prandom_u32]; \
		r6 &= 0xff; \
		r0 &= 0x0f; \
		r0 *= r6; \
		exit; \
		" :
		: __imm(bpf_map_lookup_elem),
		__imm_addr(map_hash_8b),
		__imm(bpf_get_prandom_u32)
		: __clobber_all);
		}

		SEC("socket")
		__description("bounds checks after 32-bit truncation. test 1")
		__success __failure_unpriv __msg_unpriv("R0 leaks addr")