From e7d3222e2e07e2a1a0aac979ef1fa5e8ef59f02c Mon Sep 17 00:00:00 2001 From: Alexander Bulekov Date: Fri, 23 Oct 2020 11:07:34 -0400 Subject: [PATCH] fuzz: Declare DMA Read callback function This patch declares the fuzz_dma_read_cb function and uses the preprocessor and linker(weak symbols) to handle these cases: When we build softmmu/all with --enable-fuzzing, there should be no strong symbol defined for fuzz_dma_read_cb, and we link against a weak stub function. When we build softmmu/fuzz with --enable-fuzzing, we link against the strong symbol in generic_fuzz.c When we build softmmu/all without --enable-fuzzing, fuzz_dma_read_cb is an empty, inlined function. As long as we don't call any other functions when building the arguments, there should be no overhead. Signed-off-by: Alexander Bulekov Reviewed-by: Darren Kenny Message-Id: <20201023150746.107063-6-alxndr@bu.edu> Signed-off-by: Thomas Huth --- include/exec/memory.h | 8 ++++++++ softmmu/memory.c | 13 +++++++++++++ 2 files changed, 21 insertions(+) diff --git a/include/exec/memory.h b/include/exec/memory.h index 93d27bff26..4aaf578ce6 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -47,6 +47,14 @@ void fuzz_dma_read_cb(size_t addr, size_t len, MemoryRegion *mr, bool is_write); +#else +static inline void fuzz_dma_read_cb(size_t addr, + size_t len, + MemoryRegion *mr, + bool is_write) +{ + /* Do Nothing */ +} #endif extern bool global_dirty_log; diff --git a/softmmu/memory.c b/softmmu/memory.c index a5d1641820..cec0e0f743 100644 --- a/softmmu/memory.c +++ b/softmmu/memory.c @@ -3246,6 +3246,19 @@ void memory_region_init_rom_device(MemoryRegion *mr, vmstate_register_ram(mr, owner_dev); } +/* + * Support softmmu builds with CONFIG_FUZZ using a weak symbol and a stub for + * the fuzz_dma_read_cb callback + */ +#ifdef CONFIG_FUZZ +void __attribute__((weak)) fuzz_dma_read_cb(size_t addr, + size_t len, + MemoryRegion *mr, + bool is_write) +{ +} +#endif + static const TypeInfo memory_region_info = { .parent = TYPE_OBJECT, .name = TYPE_MEMORY_REGION,