Re: [PATCH v2 06/15] fuzz: Add fuzzer callbacks to DMA-read functions

[Darren Kenny]

On Wednesday, 2020-08-19 at 02:11:01 -04, Alexander Bulekov wrote:
> We should be careful to not call any functions besides fuzz_dma_read_cb.
> Without --enable-fuzzing, fuzz_dma_read_cb is an empty inlined function.
>
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>

Reviewed-by: Darren Kenny <darren.kenny@oracle.com>

> ---
>  exec.c                                | 2 ++
>  include/exec/memory.h                 | 1 +
>  include/exec/memory_ldst_cached.inc.h | 3 +++
>  memory_ldst.inc.c                     | 4 ++++
>  softmmu/memory.c                      | 1 +
>  5 files changed, 11 insertions(+)
>
> diff --git a/exec.c b/exec.c
> index 6f381f98e2..c81f41514d 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -3241,6 +3241,7 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr 
> addr,
>              stn_he_p(buf, l, val);
>          } else {
>              /* RAM case */
> +            fuzz_dma_read_cb(addr, len, mr, false);
>              ram_ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l, false);
>              memcpy(buf, ram_ptr, l);
>          }
> @@ -3601,6 +3602,7 @@ void *address_space_map(AddressSpace *as,
>      memory_region_ref(mr);
>      *plen = flatview_extend_translation(fv, addr, len, mr, xlat,
>                                          l, is_write, attrs);
> +    fuzz_dma_read_cb(addr, *plen, mr, is_write);
>      ptr = qemu_ram_ptr_length(mr->ram_block, xlat, plen, true);
>  
>      return ptr;
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index 2ec3b597f1..f8b943521a 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -2444,6 +2444,7 @@ address_space_read_cached(MemoryRegionCache *cache, 
> hwaddr addr,
>                            void *buf, hwaddr len)
>  {
>      assert(addr < cache->len && len <= cache->len - addr);
> +    fuzz_dma_read_cb(cache->xlat + addr, len, cache->mrs.mr, false);
>      if (likely(cache->ptr)) {
>          memcpy(buf, cache->ptr + addr, len);
>          return MEMTX_OK;
> diff --git a/include/exec/memory_ldst_cached.inc.h 
> b/include/exec/memory_ldst_cached.inc.h
> index fd4bbb40e7..aff574039f 100644
> --- a/include/exec/memory_ldst_cached.inc.h
> +++ b/include/exec/memory_ldst_cached.inc.h
> @@ -28,6 +28,7 @@ static inline uint32_t 
> ADDRESS_SPACE_LD_CACHED(l)(MemoryRegionCache *cache,
>      hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
>  {
>      assert(addr < cache->len && 4 <= cache->len - addr);
> +    fuzz_dma_read_cb(cache->xlat + addr, 4, cache->mrs.mr, false);
>      if (likely(cache->ptr)) {
>          return LD_P(l)(cache->ptr + addr);
>      } else {
> @@ -39,6 +40,7 @@ static inline uint64_t 
> ADDRESS_SPACE_LD_CACHED(q)(MemoryRegionCache *cache,
>      hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
>  {
>      assert(addr < cache->len && 8 <= cache->len - addr);
> +    fuzz_dma_read_cb(cache->xlat + addr, 8, cache->mrs.mr, false);
>      if (likely(cache->ptr)) {
>          return LD_P(q)(cache->ptr + addr);
>      } else {
> @@ -50,6 +52,7 @@ static inline uint32_t 
> ADDRESS_SPACE_LD_CACHED(uw)(MemoryRegionCache *cache,
>      hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
>  {
>      assert(addr < cache->len && 2 <= cache->len - addr);
> +    fuzz_dma_read_cb(cache->xlat + addr, 2, cache->mrs.mr, false);
>      if (likely(cache->ptr)) {
>          return LD_P(uw)(cache->ptr + addr);
>      } else {
> diff --git a/memory_ldst.inc.c b/memory_ldst.inc.c
> index c54aee4a95..8d45d2eeff 100644
> --- a/memory_ldst.inc.c
> +++ b/memory_ldst.inc.c
> @@ -42,6 +42,7 @@ static inline uint32_t glue(address_space_ldl_internal, 
> SUFFIX)(ARG1_DECL,
>                                          MO_32 | devend_memop(endian), attrs);
>      } else {
>          /* RAM case */
> +        fuzz_dma_read_cb(addr, 4, mr, false);
>          ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
>          switch (endian) {
>          case DEVICE_LITTLE_ENDIAN:
> @@ -110,6 +111,7 @@ static inline uint64_t glue(address_space_ldq_internal, 
> SUFFIX)(ARG1_DECL,
>                                          MO_64 | devend_memop(endian), attrs);
>      } else {
>          /* RAM case */
> +        fuzz_dma_read_cb(addr, 8, mr, false);
>          ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
>          switch (endian) {
>          case DEVICE_LITTLE_ENDIAN:
> @@ -175,6 +177,7 @@ uint32_t glue(address_space_ldub, SUFFIX)(ARG1_DECL,
>          r = memory_region_dispatch_read(mr, addr1, &val, MO_8, attrs);
>      } else {
>          /* RAM case */
> +        fuzz_dma_read_cb(addr, 1, mr, false);
>          ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
>          val = ldub_p(ptr);
>          r = MEMTX_OK;
> @@ -212,6 +215,7 @@ static inline uint32_t glue(address_space_lduw_internal, 
> SUFFIX)(ARG1_DECL,
>                                          MO_16 | devend_memop(endian), attrs);
>      } else {
>          /* RAM case */
> +        fuzz_dma_read_cb(addr, 2, mr, false);
>          ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
>          switch (endian) {
>          case DEVICE_LITTLE_ENDIAN:
> diff --git a/softmmu/memory.c b/softmmu/memory.c
> index b0c2cf2535..be87044641 100644
> --- a/softmmu/memory.c
> +++ b/softmmu/memory.c
> @@ -1405,6 +1405,7 @@ MemTxResult memory_region_dispatch_read(MemoryRegion 
> *mr,
>      unsigned size = memop_size(op);
>      MemTxResult r;
>  
> +    fuzz_dma_read_cb(addr, size, mr, false);
>      if (!memory_region_access_valid(mr, addr, size, false, attrs)) {
>          *pval = unassigned_mem_read(mr, addr, size);
>          return MEMTX_DECODE_ERROR;
> -- 
> 2.27.0