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1// SPDX-License-Identifier: GPL-2.02/* Converted from tools/testing/selftests/bpf/verifier/raw_tp_writable.c */3 4#include <linux/bpf.h>5#include <bpf/bpf_helpers.h>6#include "bpf_misc.h"7 8struct {9 __uint(type, BPF_MAP_TYPE_HASH);10 __uint(max_entries, 1);11 __type(key, long long);12 __type(value, long long);13} map_hash_8b SEC(".maps");14 15SEC("raw_tracepoint.w")16__description("raw_tracepoint_writable: reject variable offset")17__failure18__msg("R6 invalid variable buffer offset: off=0, var_off=(0x0; 0xffffffff)")19__flag(BPF_F_ANY_ALIGNMENT)20__naked void tracepoint_writable_reject_variable_offset(void)21{22 asm volatile (" \23 /* r6 is our tp buffer */ \24 r6 = *(u64*)(r1 + 0); \25 r1 = %[map_hash_8b] ll; \26 /* move the key (== 0) to r10-8 */ \27 w0 = 0; \28 r2 = r10; \29 r2 += -8; \30 *(u64*)(r2 + 0) = r0; \31 /* lookup in the map */ \32 call %[bpf_map_lookup_elem]; \33 /* exit clean if null */ \34 if r0 != 0 goto l0_%=; \35 exit; \36l0_%=: /* shift the buffer pointer to a variable location */\37 r0 = *(u32*)(r0 + 0); \38 r6 += r0; \39 /* clobber whatever's there */ \40 r7 = 4242; \41 *(u64*)(r6 + 0) = r7; \42 r0 = 0; \43 exit; \44" :45 : __imm(bpf_map_lookup_elem),46 __imm_addr(map_hash_8b)47 : __clobber_all);48}49 50char _license[] SEC("license") = "GPL";51