Примеры ошибок, обнаруженных с помощью диагностики V784

V784. The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits.

Perl 5

V784 The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. inffast.c 296

void ZLIB_INTERNAL inflate_fast(z_streamp strm, unsigned start)
{
  ....
  unsigned long hold;         /* local strm->hold */
  unsigned bits;              /* local strm->bits */
  ....
  hold &= (1U << bits) - 1;
  ....
}

LLVM/Clang

V784 The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. RuntimeDyld.cpp 815

unsigned getStubAlignment() override {
  if (Arch == Triple::systemz)
    return 8;
  else
    return 1;
}

Expected<unsigned>
RuntimeDyldImpl::emitSection(const ObjectFile &Obj,
                             const SectionRef &Section,
                             bool IsCode) {
  ....
  uint64_t DataSize = Section.getSize();
  ....
  if (StubBufSize > 0)
    DataSize &= ~(getStubAlignment() - 1);
  ....
}

Qemu

V784 The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. cadence_gem.c 1486

typedef struct CadenceGEMState {
  ....
  uint32_t regs_ro[CADENCE_GEM_MAXREG];
}
....
static void gem_write(void *opaque, hwaddr offset, uint64_t val,
        unsigned size)
{
  ....
  val &= ~(s->regs_ro[offset]);
  ....
}

LLVM/Clang

V784 [CWE-197, CERT-INT31-C] The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. Types.h 529

uint64_t NullabilityPayload = 0;

static constexpr const unsigned NullabilityKindMask = 0x3;

void addTypeInfo(unsigned index, NullabilityKind kind) {
  ....
  NullabilityPayload &=
    ~(NullabilityKindMask << (index * NullabilityKindSize));
  ....
}

iSulad

V784 [CWE-197, CERT-INT31-C] The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. utils_fs.c 257

struct mount_option_element {
  const char *option;
  bool clear;
  int flag;
};

static void do_parse_mntopt(const char *opt, unsigned long *mflags, char **data)
{
  size_t i = 0;

  for (i = 0; i < sizeof(g_mount_options) / sizeof(g_mount_options[0]); i++) {
    if (strncmp(opt, g_mount_options[i].option,
                strlen(g_mount_options[i].option)) == 0) {
      if (g_mount_options[i].clear) {
        *mflags &= ~g_mount_options[i].flag;
  ....
}

DPDK

V784 The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. hinic_pmd_flow.c 2292

#define HINIC_MAX_Q_FILTERS  64 /* hinic just support 64 filter types */

/* Structure to store filters' info. */
struct hinic_filter_info {
  ....
  uint64_t type_mask;  /* Bit mask for every used filter */
  ....
};

static inline void
hinic_ethertype_filter_remove(struct hinic_filter_info *filter_info,
            uint8_t idx)
{
  if (idx >= HINIC_MAX_Q_FILTERS)
    return;

  filter_info->pkt_type = 0;
  filter_info->type_mask &= ~(1 << idx);
  filter_info->pkt_filters[idx].pkt_proto = (uint16_t)0;
  filter_info->pkt_filters[idx].enable = FALSE;
  filter_info->pkt_filters[idx].qid = 0;
}

Similar errors can be found in some other places:

• V784 The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. dpaa2_sec_dpseci.c 1755
• V784 The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. dpaa_sec.c 1913
• V784 The size of the bit mask is less than the size of the first operand. This will cause the loss of higher bits. dpaa_eventdev.c 104
• And 7 additional diagnostic messages.