diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/verifier_raw_tp_writable.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_raw_tp_writable.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_raw_tp_writable.c b/tools/testing/selftests/bpf/progs/verifier_raw_tp_writable.c new file mode 100644 index 000000000000..14a0172e2141 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/verifier_raw_tp_writable.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Converted from tools/testing/selftests/bpf/verifier/raw_tp_writable.c */ + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include "bpf_misc.h" + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 1); + __type(key, long long); + __type(value, long long); +} map_hash_8b SEC(".maps"); + +SEC("raw_tracepoint.w") +__description("raw_tracepoint_writable: reject variable offset") +__failure +__msg("R6 invalid variable buffer offset: off=0, var_off=(0x0; 0xffffffff)") +__flag(BPF_F_ANY_ALIGNMENT) +__naked void tracepoint_writable_reject_variable_offset(void) +{ + asm volatile (" \ + /* r6 is our tp buffer */ \ + r6 = *(u64*)(r1 + 0); \ + r1 = %[map_hash_8b] ll; \ + /* move the key (== 0) to r10-8 */ \ + w0 = 0; \ + r2 = r10; \ + r2 += -8; \ + *(u64*)(r2 + 0) = r0; \ + /* lookup in the map */ \ + call %[bpf_map_lookup_elem]; \ + /* exit clean if null */ \ + if r0 != 0 goto l0_%=; \ + exit; \ +l0_%=: /* shift the buffer pointer to a variable location */\ + r0 = *(u32*)(r0 + 0); \ + r6 += r0; \ + /* clobber whatever's there */ \ + r7 = 4242; \ + *(u64*)(r6 + 0) = r7; \ + r0 = 0; \ + exit; \ +" : + : __imm(bpf_map_lookup_elem), + __imm_addr(map_hash_8b) + : __clobber_all); +} + +char _license[] SEC("license") = "GPL"; |