mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-29 05:44:11 +00:00
Code Issues Releases Wiki Activity

selftests/bpf: test case for relaxed prunning of active_lock.id

Browse source 
Check that verifier.c:states_equal() uses check_ids() to match
consistent active_lock/map_value configurations. This allows to prune
states with active spin locks even if numerical values of
active_lock ids do not match across compared states.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20221209135733.28851-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Eduard Zingerman 2022-12-09 15:57:33 +02:00 committed by Alexei Starovoitov
parent 2026f2062d
commit efd6286ff7
1 changed files with 75 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

75
tools/testing/selftests/bpf/verifier/spin_lock.c
View file

@ -370,3 +370,78 @@
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.flags = BPF_F_TEST_STATE_FREQ,
},
/* Make sure that regsafe() compares ids for spin lock records using
* check_ids():
* 1: r9 = map_lookup_elem(...) ; r9.id == 1
* 2: r8 = map_lookup_elem(...) ; r8.id == 2
* 3: r7 = ktime_get_ns()
* 4: r6 = ktime_get_ns()
* 5: if r6 > r7 goto <9>
* 6: spin_lock(r8)
* 7: r9 = r8
* 8: goto <10>
* 9: spin_lock(r9)
* 10: spin_unlock(r9) ; r9.id == 1 || r9.id == 2 and lock is active,
* ; second visit to (10) should be considered safe
* ; if check_ids() is used.
* 11: exit(0)
*/
{
"spin_lock: regsafe() check_ids() similar id mappings",
.insns = {
BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
/* r9 = map_lookup_elem(...) */
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
BPF_LD_MAP_FD(BPF_REG_1,
0),
BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 24),
BPF_MOV64_REG(BPF_REG_9, BPF_REG_0),
/* r8 = map_lookup_elem(...) */
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
BPF_LD_MAP_FD(BPF_REG_1,
0),
BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 18),
BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),
/* r7 = ktime_get_ns() */
BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
/* r6 = ktime_get_ns() */
BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
/* if r6 > r7 goto +5 ; no new information about the state is derived from
* ; this check, thus produced verifier states differ
* ; only in 'insn_idx'
* spin_lock(r8)
* r9 = r8
* goto unlock
*/
BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 5),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 4),
BPF_EMIT_CALL(BPF_FUNC_spin_lock),
BPF_MOV64_REG(BPF_REG_9, BPF_REG_8),
BPF_JMP_A(3),
/* spin_lock(r9) */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_9),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 4),
BPF_EMIT_CALL(BPF_FUNC_spin_lock),
/* spin_unlock(r9) */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_9),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 4),
BPF_EMIT_CALL(BPF_FUNC_spin_unlock),
/* exit(0) */
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_spin_lock = { 3, 10 },
.result = VERBOSE_ACCEPT,
.errstr = "28: safe",
.result_unpriv = REJECT,
.errstr_unpriv = "",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
.flags = BPF_F_TEST_STATE_FREQ,
},