// 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";