diff options
| author | Siddharth Chintamaneni <sidchintamaneni@gmail.com> | 2026-09-02 17:14:14 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-12 10:26:05 -0700 |
| commit | ac781acaef4904b9be64a7b5755c778e5d76ede6 (patch) | |
| tree | d79ef915aaa4644c13caee6388685ee811e42ad8 /tools/testing/selftests/bpf | |
| parent | 0d7823cd4cda35f2060a685fa276ff7709915abc (diff) | |
selftests/bpf: Test terminal gotox instructions
Add tests that place gotox at the end of the main program and a
subprogram, with each jump-table target preceding the gotox instruction.
This tests gotox as a valid non-fallthrough terminal instruction.
Signed-off-by: Siddharth Chintamaneni <sidchintamaneni@gmail.com>
Reviewed-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20260902171414.96165-2-sidchintamaneni@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_gotox.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_gotox.c b/tools/testing/selftests/bpf/progs/verifier_gotox.c index 5b18c9a27717..0e27c2c79c57 100644 --- a/tools/testing/selftests/bpf/progs/verifier_gotox.c +++ b/tools/testing/selftests/bpf/progs/verifier_gotox.c @@ -47,6 +47,54 @@ DEFINE_SIMPLE_JUMP_TABLE_PROG(reserved_field_src_reg, BPF_REG_1, 0, 0, __fa DEFINE_SIMPLE_JUMP_TABLE_PROG(reserved_field_non_zero_off, BPF_REG_0, 1, 0, __failure __msg("BPF_JA|BPF_X uses reserved fields")) DEFINE_SIMPLE_JUMP_TABLE_PROG(reserved_field_non_zero_imm, BPF_REG_0, 0, 1, __failure __msg("BPF_JA|BPF_X uses reserved fields")) +#define DEFINE_TERMINAL_GOTOX_PROG(NAME, BASE) \ + __naked void NAME(void) \ + { \ + asm volatile (" \ + .pushsection .jumptables,\"\",@progbits; \ +jt0_%=: \ + .quad ret0_%= - " BASE "; \ + .size jt0_%=, 8; \ + .global jt0_%=; \ + .popsection; \ + \ + r0 = jt0_%= ll; \ + r0 = *(u64 *)(r0 + 0); \ + goto end_%=; \ +ret0_%=: \ + r0 = 0; \ + exit; \ +end_%=: \ + .8byte %[gotox_r0]; \ +" : \ + : __imm_insn(gotox_r0, BPF_RAW_INSN(BPF_JMP | BPF_JA | BPF_X, \ + BPF_REG_0, 0, 0, 0)) \ + : __clobber_all); \ + } + +SEC("socket") +__success __retval(0) +DEFINE_TERMINAL_GOTOX_PROG(jump_table_terminal_gotox, "socket") + +static __noinline __used +DEFINE_TERMINAL_GOTOX_PROG(terminal_gotox_subprog1, ".text") + +static __noinline __used int terminal_gotox_subprog2(void) +{ + return 0; +} + +SEC("socket") +__success __retval(0) +__naked void jump_table_terminal_gotox_subprog(void) +{ + asm volatile (" \ + call terminal_gotox_subprog1; \ + call terminal_gotox_subprog2; \ + exit; \ +" ::: __clobber_all); +} + /* * Gotox is forbidden when there is no jump table loaded * which points to the sub-function where the gotox is used |