51 lines
1.3 KiB
C
51 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Converted from tools/testing/selftests/bpf/verifier/raw_tp_writable.c */
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include "bpf_misc.h"
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struct {
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__uint(type, BPF_MAP_TYPE_HASH);
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__uint(max_entries, 1);
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__type(key, long long);
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__type(value, long long);
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} map_hash_8b SEC(".maps");
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SEC("raw_tracepoint.w")
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__description("raw_tracepoint_writable: reject variable offset")
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__failure
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__msg("R6 invalid variable buffer offset: off=0, var_off=(0x0; 0xffffffff)")
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__flag(BPF_F_ANY_ALIGNMENT)
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__naked void tracepoint_writable_reject_variable_offset(void)
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{
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asm volatile (" \
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/* r6 is our tp buffer */ \
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r6 = *(u64*)(r1 + 0); \
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r1 = %[map_hash_8b] ll; \
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/* move the key (== 0) to r10-8 */ \
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w0 = 0; \
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r2 = r10; \
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r2 += -8; \
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*(u64*)(r2 + 0) = r0; \
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/* lookup in the map */ \
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call %[bpf_map_lookup_elem]; \
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/* exit clean if null */ \
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if r0 != 0 goto l0_%=; \
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exit; \
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l0_%=: /* shift the buffer pointer to a variable location */\
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r0 = *(u32*)(r0 + 0); \
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r6 += r0; \
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/* clobber whatever's there */ \
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r7 = 4242; \
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*(u64*)(r6 + 0) = r7; \
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r0 = 0; \
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exit; \
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" :
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: __imm(bpf_map_lookup_elem),
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__imm_addr(map_hash_8b)
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: __clobber_all);
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}
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char _license[] SEC("license") = "GPL";
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