github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-26 16:12:59 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

selftests/bpf: Add a test for ids=0 to verifier_scalar_ids test

Browse Source 
Test that two registers with their id=0 (unlinked) in the cached state
can be mapped to a single id (linked) in the current state.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20260203165102.2302462-6-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Puranjay Mohan 2026-02-03 08:51:01 -08:00 committed by Alexei Starovoitov
parent b0388bafa4
commit f6ef5584cc
1 changed files with 45 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
tools/testing/selftests/bpf/progs/verifier_scalar_ids.c
View File

@ -715,6 +715,51 @@ __naked void ignore_unique_scalar_ids_old(void)
: __clobber_all);
}
/* Check that two registers with 0 scalar IDs in a verified state can be mapped
* to the same scalar ID in current state.
*/
SEC("socket")
__success __log_level(2)
/* The states should be equivalent on reaching insn 12.
*/
__msg("12: safe")
__msg("processed 17 insns")
__flag(BPF_F_TEST_STATE_FREQ)
__naked void two_nil_old_ids_one_cur_id(void)
{
asm volatile (
/* Give unique scalar IDs to r{6,7} */
"call %[bpf_ktime_get_ns];"
"r0 &= 0xff;"
"r6 = r0;"
"r6 *= 1;"
"call %[bpf_ktime_get_ns];"
"r0 &= 0xff;"
"r7 = r0;"
"r7 *= 1;"
"r0 = 0;"
/* Maybe make r{6,7} IDs identical */
"if r6 > r7 goto l0_%=;"
"goto l1_%=;"
"l0_%=:"
"r6 = r7;"
"l1_%=:"
/* Mark r{6,7} precise.
* Get here in two states:
* - first: r6{.id=0}, r7{.id=0} (cached state)
* - second: r6{.id=A}, r7{.id=A}
* Verifier considers such states equivalent.
* Thus "exit;" would be verified only once.
*/
"r2 = r10;"
"r2 += r6;"
"r2 += r7;"
"exit;"
:
: __imm(bpf_ktime_get_ns)
: __clobber_all);
}
/* Check that two different scalar IDs in a verified state can't be
* mapped to the same scalar ID in current state.
*/