tools/testing/selftests/bpf/progs/verifier_xadd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Converted from tools/testing/selftests/bpf/verifier/xadd.c */
   3
   4 #include <linux/bpf.h>
   5 #include <bpf/bpf_helpers.h>
   6 #include "bpf_misc.h"
   7
   8 struct {
   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
  15 SEC("tc")
  16 __description("xadd/w check unaligned stack")
  17 __failure __msg("misaligned stack access off")
  18 __naked void xadd_w_check_unaligned_stack(void)
  19 {
  20         asm volatile ("                                 \
  21         r0 = 1;                                         \
  22         *(u64*)(r10 - 8) = r0;                          \
  23         lock *(u32 *)(r10 - 7) += w0;                   \
  24         r0 = *(u64*)(r10 - 8);                          \
  25         exit;                                           \
  26 "       ::: __clobber_all);
  27 }
  28
  29 SEC("tc")
  30 __description("xadd/w check unaligned map")
  31 __failure __msg("misaligned value access off")
  32 __naked void xadd_w_check_unaligned_map(void)
  33 {
  34         asm volatile ("                                 \
  35         r1 = 0;                                         \
  36         *(u64*)(r10 - 8) = r1;                          \
  37         r2 = r10;                                       \
  38         r2 += -8;                                       \
  39         r1 = %[map_hash_8b] ll;                         \
  40         call %[bpf_map_lookup_elem];                    \
  41         if r0 != 0 goto l0_%=;                          \
  42         exit;                                           \
  43 l0_%=:  r1 = 1;                                         \
  44         lock *(u32 *)(r0 + 3) += w1;                    \
  45         r0 = *(u32*)(r0 + 3);                           \
  46         exit;                                           \
  47 "       :
  48         : __imm(bpf_map_lookup_elem),
  49           __imm_addr(map_hash_8b)
  50         : __clobber_all);
  51 }
  52
  53 SEC("xdp")
  54 __description("xadd/w check unaligned pkt")
  55 __failure __msg("BPF_ATOMIC stores into R2 pkt is not allowed")
  56 __flag(BPF_F_ANY_ALIGNMENT)
  57 __naked void xadd_w_check_unaligned_pkt(void)
  58 {
  59         asm volatile ("                                 \
  60         r2 = *(u32*)(r1 + %[xdp_md_data]);              \
  61         r3 = *(u32*)(r1 + %[xdp_md_data_end]);          \
  62         r1 = r2;                                        \
  63         r1 += 8;                                        \
  64         if r1 < r3 goto l0_%=;                          \
  65         r0 = 99;                                        \
  66         goto l1_%=;                                     \
  67 l0_%=:  r0 = 1;                                         \
  68         r1 = 0;                                         \
  69         *(u32*)(r2 + 0) = r1;                           \
  70         r1 = 0;                                         \
  71         *(u32*)(r2 + 3) = r1;                           \
  72         lock *(u32 *)(r2 + 1) += w0;                    \
  73         lock *(u32 *)(r2 + 2) += w0;                    \
  74         r0 = *(u32*)(r2 + 1);                           \
  75 l1_%=:  exit;                                           \
  76 "       :
  77         : __imm_const(xdp_md_data, offsetof(struct xdp_md, data)),
  78           __imm_const(xdp_md_data_end, offsetof(struct xdp_md, data_end))
  79         : __clobber_all);
  80 }
  81
  82 SEC("tc")
  83 __description("xadd/w check whether src/dst got mangled, 1")
  84 __success __retval(3)
  85 __naked void src_dst_got_mangled_1(void)
  86 {
  87         asm volatile ("                                 \
  88         r0 = 1;                                         \
  89         r6 = r0;                                        \
  90         r7 = r10;                                       \
  91         *(u64*)(r10 - 8) = r0;                          \
  92         lock *(u64 *)(r10 - 8) += r0;                   \
  93         lock *(u64 *)(r10 - 8) += r0;                   \
  94         if r6 != r0 goto l0_%=;                         \
  95         if r7 != r10 goto l0_%=;                        \
  96         r0 = *(u64*)(r10 - 8);                          \
  97         exit;                                           \
  98 l0_%=:  r0 = 42;                                        \
  99         exit;                                           \
 100 "       ::: __clobber_all);
 101 }
 102
 103 SEC("tc")
 104 __description("xadd/w check whether src/dst got mangled, 2")
 105 __success __retval(3)
 106 __naked void src_dst_got_mangled_2(void)
 107 {
 108         asm volatile ("                                 \
 109         r0 = 1;                                         \
 110         r6 = r0;                                        \
 111         r7 = r10;                                       \
 112         *(u32*)(r10 - 8) = r0;                          \
 113         lock *(u32 *)(r10 - 8) += w0;                   \
 114         lock *(u32 *)(r10 - 8) += w0;                   \
 115         if r6 != r0 goto l0_%=;                         \
 116         if r7 != r10 goto l0_%=;                        \
 117         r0 = *(u32*)(r10 - 8);                          \
 118         exit;                                           \
 119 l0_%=:  r0 = 42;                                        \
 120         exit;                                           \
 121 "       ::: __clobber_all);
 122 }
 123
 124 char _license[] SEC("license") = "GPL";