/* * Generic Virtual-Device Fuzzing Target * * Copyright Red Hat Inc., 2020 * * Authors: * Alexander Bulekov * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. */ #include "qemu/osdep.h" #include #include "hw/core/cpu.h" #include "tests/qtest/libqos/libqtest.h" #include "tests/qtest/libqos/pci-pc.h" #include "fuzz.h" #include "fork_fuzz.h" #include "exec/address-spaces.h" #include "string.h" #include "exec/memory.h" #include "exec/ramblock.h" #include "exec/address-spaces.h" #include "hw/qdev-core.h" #include "hw/pci/pci.h" #include "hw/boards.h" #include "generic_fuzz_configs.h" #include "hw/mem/sparse-mem.h" /* * SEPARATOR is used to separate "operations" in the fuzz input */ #define SEPARATOR "FUZZ" enum cmds { OP_IN, OP_OUT, OP_READ, OP_WRITE, OP_PCI_READ, OP_PCI_WRITE, OP_DISABLE_PCI, OP_ADD_DMA_PATTERN, OP_CLEAR_DMA_PATTERNS, OP_CLOCK_STEP, }; #define DEFAULT_TIMEOUT_US 100000 #define USEC_IN_SEC 1000000000 #define MAX_DMA_FILL_SIZE 0x10000 #define PCI_HOST_BRIDGE_CFG 0xcf8 #define PCI_HOST_BRIDGE_DATA 0xcfc typedef struct { ram_addr_t addr; ram_addr_t size; /* The number of bytes until the end of the I/O region */ } address_range; static useconds_t timeout = DEFAULT_TIMEOUT_US; static bool qtest_log_enabled; MemoryRegion *sparse_mem_mr; /* * A pattern used to populate a DMA region or perform a memwrite. This is * useful for e.g. populating tables of unique addresses. * Example {.index = 1; .stride = 2; .len = 3; .data = "\x00\x01\x02"} * Renders as: 00 01 02 00 03 02 00 05 02 00 07 02 ... */ typedef struct { uint8_t index; /* Index of a byte to increment by stride */ uint8_t stride; /* Increment each index'th byte by this amount */ size_t len; const uint8_t *data; } pattern; /* Avoid filling the same DMA region between MMIO/PIO commands ? */ static bool avoid_double_fetches; static QTestState *qts_global; /* Need a global for the DMA callback */ /* * List of memory regions that are children of QOM objects specified by the * user for fuzzing. */ static GHashTable *fuzzable_memoryregions; static GPtrArray *fuzzable_pci_devices; struct get_io_cb_info { int index; int found; address_range result; }; static int get_io_address_cb(Int128 start, Int128 size, const MemoryRegion *mr, void *opaque) { struct get_io_cb_info *info = opaque; if (g_hash_table_lookup(fuzzable_memoryregions, mr)) { if (info->index == 0) { info->result.addr = (ram_addr_t)start; info->result.size = (ram_addr_t)size; info->found = 1; return 1; } info->index--; } return 0; } /* * List of dma regions populated since the last fuzzing command. Used to ensure * that we only write to each DMA address once, to avoid race conditions when * building reproducers. */ static GArray *dma_regions; static GArray *dma_patterns; static int dma_pattern_index; static bool pci_disabled; /* * Allocate a block of memory and populate it with a pattern. */ static void *pattern_alloc(pattern p, size_t len) { int i; uint8_t *buf = g_malloc(len); uint8_t sum = 0; for (i = 0; i < len; ++i) { buf[i] = p.data[i % p.len]; if ((i % p.len) == p.index) { buf[i] += sum; sum += p.stride; } } return buf; } static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr) { unsigned access_size_max = mr->ops->valid.max_access_size; /* * Regions are assumed to support 1-4 byte accesses unless * otherwise specified. */ if (access_size_max == 0) { access_size_max = 4; } /* Bound the maximum access by the alignment of the address. */ if (!mr->ops->impl.unaligned) { unsigned align_size_max = addr & -addr; if (align_size_max != 0 && align_size_max < access_size_max) { access_size_max = align_size_max; } } /* Don't attempt accesses larger than the maximum. */ if (l > access_size_max) { l = access_size_max; } l = pow2floor(l); return l; } /* * Call-back for functions that perform DMA reads from guest memory. Confirm * that the region has not already been populated since the last loop in * generic_fuzz(), avoiding potential race-conditions, which we don't have * a good way for reproducing right now. */ void fuzz_dma_read_cb(size_t addr, size_t len, MemoryRegion *mr) { /* Are we in the generic-fuzzer or are we using another fuzz-target? */ if (!qts_global) { return; } /* * Return immediately if: * - We have no DMA patterns defined * - The length of the DMA read request is zero * - The DMA read is hitting an MR other than the machine's main RAM * - The DMA request hits past the bounds of our RAM */ if (dma_patterns->len == 0 || len == 0 || (mr != current_machine->ram && mr != sparse_mem_mr)) { return; } /* * If we overlap with any existing dma_regions, split the range and only * populate the non-overlapping parts. */ address_range region; bool double_fetch = false; for (int i = 0; i < dma_regions->len && (avoid_double_fetches || qtest_log_enabled); ++i) { region = g_array_index(dma_regions, address_range, i); if (addr < region.addr + region.size && addr + len > region.addr) { double_fetch = true; if (addr < region.addr && avoid_double_fetches) { fuzz_dma_read_cb(addr, region.addr - addr, mr); } if (addr + len > region.addr + region.size && avoid_double_fetches) { fuzz_dma_read_cb(region.addr + region.size, addr + len - (region.addr + region.size), mr); } return; } } /* Cap the length of the DMA access to something reasonable */ len = MIN(len, MAX_DMA_FILL_SIZE); address_range ar = {addr, len}; g_array_append_val(dma_regions, ar); pattern p = g_array_index(dma_patterns, pattern, dma_pattern_index); void *buf_base = pattern_alloc(p, ar.size); void *buf = buf_base; hwaddr l, addr1; MemoryRegion *mr1; while (len > 0) { l = len; mr1 = address_space_translate(first_cpu->as, addr, &addr1, &l, true, MEMTXATTRS_UNSPECIFIED); if (!(memory_region_is_ram(mr1) || memory_region_is_romd(mr1)) && mr1 != sparse_mem_mr) { l = memory_access_size(mr1, l, addr1); } else { /* ROM/RAM case */ if (qtest_log_enabled) { /* * With QTEST_LOG, use a normal, slow QTest memwrite. Prefix the log * that will be written by qtest.c with a DMA tag, so we can reorder * the resulting QTest trace so the DMA fills precede the last PIO/MMIO * command. */ fprintf(stderr, "[DMA] "); if (double_fetch) { fprintf(stderr, "[DOUBLE-FETCH] "); } fflush(stderr); } qtest_memwrite(qts_global, addr, buf, l); } len -= l; buf += l; addr += l; } g_free(buf_base); /* Increment the index of the pattern for the next DMA access */ dma_pattern_index = (dma_pattern_index + 1) % dma_patterns->len; } /* * Here we want to convert a fuzzer-provided [io-region-index, offset] to * a physical address. To do this, we iterate over all of the matched * MemoryRegions. Check whether each region exists within the particular io * space. Return the absolute address of the offset within the index'th region * that is a subregion of the io_space and the distance until the end of the * memory region. */ static bool get_io_address(address_range *result, AddressSpace *as, uint8_t index, uint32_t offset) { FlatView *view; view = as->current_map; g_assert(view); struct get_io_cb_info cb_info = {}; cb_info.index = index; /* * Loop around the FlatView until we match "index" number of * fuzzable_memoryregions, or until we know that there are no matching * memory_regions. */ do { flatview_for_each_range(view, get_io_address_cb , &cb_info); } while (cb_info.index != index && !cb_info.found); *result = cb_info.result; if (result->size) { offset = offset % result->size; result->addr += offset; result->size -= offset; } return cb_info.found; } static bool get_pio_address(address_range *result, uint8_t index, uint16_t offset) { /* * PIO BARs can be set past the maximum port address (0xFFFF). Thus, result * can contain an addr that extends past the PIO space. When we pass this * address to qtest_in/qtest_out, it is cast to a uint16_t, so we might end * up fuzzing a completely different MemoryRegion/Device. Therefore, check * that the address here is within the PIO space limits. */ bool found = get_io_address(result, &address_space_io, index, offset); return result->addr <= 0xFFFF ? found : false; } static bool get_mmio_address(address_range *result, uint8_t index, uint32_t offset) { return get_io_address(result, &address_space_memory, index, offset); } static void op_in(QTestState *s, const unsigned char * data, size_t len) { enum Sizes {Byte, Word, Long, end_sizes}; struct { uint8_t size; uint8_t base; uint16_t offset; } a; address_range abs; if (len < sizeof(a)) { return; } memcpy(&a, data, sizeof(a)); if (get_pio_address(&abs, a.base, a.offset) == 0) { return; } switch (a.size %= end_sizes) { case Byte: qtest_inb(s, abs.addr); break; case Word: if (abs.size >= 2) { qtest_inw(s, abs.addr); } break; case Long: if (abs.size >= 4) { qtest_inl(s, abs.addr); } break; } } static void op_out(QTestState *s, const unsigned char * data, size_t len) { enum Sizes {Byte, Word, Long, end_sizes}; struct { uint8_t size; uint8_t base; uint16_t offset; uint32_t value; } a; address_range abs; if (len < sizeof(a)) { return; } memcpy(&a, data, sizeof(a)); if (get_pio_address(&abs, a.base, a.offset) == 0) { return; } switch (a.size %= end_sizes) { case Byte: qtest_outb(s, abs.addr, a.value & 0xFF); break; case Word: if (abs.size >= 2) { qtest_outw(s, abs.addr, a.value & 0xFFFF); } break; case Long: if (abs.size >= 4) { qtest_outl(s, abs.addr, a.value); } break; } } static void op_read(QTestState *s, const unsigned char * data, size_t len) { enum Sizes {Byte, Word, Long, Quad, end_sizes}; struct { uint8_t size; uint8_t base; uint32_t offset; } a; address_range abs; if (len < sizeof(a)) { return; } memcpy(&a, data, sizeof(a)); if (get_mmio_address(&abs, a.base, a.offset) == 0) { return; } switch (a.size %= end_sizes) { case Byte: qtest_readb(s, abs.addr); break; case Word: if (abs.size >= 2) { qtest_readw(s, abs.addr); } break; case Long: if (abs.size >= 4) { qtest_readl(s, abs.addr); } break; case Quad: if (abs.size >= 8) { qtest_readq(s, abs.addr); } break; } } static void op_write(QTestState *s, const unsigned char * data, size_t len) { enum Sizes {Byte, Word, Long, Quad, end_sizes}; struct { uint8_t size; uint8_t base; uint32_t offset; uint64_t value; } a; address_range abs; if (len < sizeof(a)) { return; } memcpy(&a, data, sizeof(a)); if (get_mmio_address(&abs, a.base, a.offset) == 0) { return; } switch (a.size %= end_sizes) { case Byte: qtest_writeb(s, abs.addr, a.value & 0xFF); break; case Word: if (abs.size >= 2) { qtest_writew(s, abs.addr, a.value & 0xFFFF); } break; case Long: if (abs.size >= 4) { qtest_writel(s, abs.addr, a.value & 0xFFFFFFFF); } break; case Quad: if (abs.size >= 8) { qtest_writeq(s, abs.addr, a.value); } break; } } static void op_pci_read(QTestState *s, const unsigned char * data, size_t len) { enum Sizes {Byte, Word, Long, end_sizes}; struct { uint8_t size; uint8_t base; uint8_t offset; } a; if (len < sizeof(a) || fuzzable_pci_devices->len == 0 || pci_disabled) { return; } memcpy(&a, data, sizeof(a)); PCIDevice *dev = g_ptr_array_index(fuzzable_pci_devices, a.base % fuzzable_pci_devices->len); int devfn = dev->devfn; qtest_outl(s, PCI_HOST_BRIDGE_CFG, (1U << 31) | (devfn << 8) | a.offset); switch (a.size %= end_sizes) { case Byte: qtest_inb(s, PCI_HOST_BRIDGE_DATA); break; case Word: qtest_inw(s, PCI_HOST_BRIDGE_DATA); break; case Long: qtest_inl(s, PCI_HOST_BRIDGE_DATA); break; } } static void op_pci_write(QTestState *s, const unsigned char * data, size_t len) { enum Sizes {Byte, Word, Long, end_sizes}; struct { uint8_t size; uint8_t base; uint8_t offset; uint32_t value; } a; if (len < sizeof(a) || fuzzable_pci_devices->len == 0 || pci_disabled) { return; } memcpy(&a, data, sizeof(a)); PCIDevice *dev = g_ptr_array_index(fuzzable_pci_devices, a.base % fuzzable_pci_devices->len); int devfn = dev->devfn; qtest_outl(s, PCI_HOST_BRIDGE_CFG, (1U << 31) | (devfn << 8) | a.offset); switch (a.size %= end_sizes) { case Byte: qtest_outb(s, PCI_HOST_BRIDGE_DATA, a.value & 0xFF); break; case Word: qtest_outw(s, PCI_HOST_BRIDGE_DATA, a.value & 0xFFFF); break; case Long: qtest_outl(s, PCI_HOST_BRIDGE_DATA, a.value & 0xFFFFFFFF); break; } } static void op_add_dma_pattern(QTestState *s, const unsigned char *data, size_t len) { struct { /* * index and stride can be used to increment the index-th byte of the * pattern by the value stride, for each loop of the pattern. */ uint8_t index; uint8_t stride; } a; if (len < sizeof(a) + 1) { return; } memcpy(&a, data, sizeof(a)); pattern p = {a.index, a.stride, len - sizeof(a), data + sizeof(a)}; p.index = a.index % p.len; g_array_append_val(dma_patterns, p); return; } static void op_clear_dma_patterns(QTestState *s, const unsigned char *data, size_t len) { g_array_set_size(dma_patterns, 0); dma_pattern_index = 0; } static void op_clock_step(QTestState *s, const unsigned char *data, size_t len) { qtest_clock_step_next(s); } static void op_disable_pci(QTestState *s, const unsigned char *data, size_t len) { pci_disabled = true; } static void handle_timeout(int sig) { if (qtest_log_enabled) { fprintf(stderr, "[Timeout]\n"); fflush(stderr); } /* * If there is a crash, libfuzzer/ASAN forks a child to run an * "llvm-symbolizer" process for printing out a pretty stacktrace. It * communicates with this child using a pipe. If we timeout+Exit, while * libfuzzer is still communicating with the llvm-symbolizer child, we will * be left with an orphan llvm-symbolizer process. Sometimes, this appears * to lead to a deadlock in the forkserver. Use waitpid to check if there * are any waitable children. If so, exit out of the signal-handler, and * let libfuzzer finish communicating with the child, and exit, on its own. */ if (waitpid(-1, NULL, WNOHANG) == 0) { return; } _Exit(0); } /* * Here, we interpret random bytes from the fuzzer, as a sequence of commands. * Some commands can be variable-width, so we use a separator, SEPARATOR, to * specify the boundaries between commands. SEPARATOR is used to separate * "operations" in the fuzz input. Why use a separator, instead of just using * the operations' length to identify operation boundaries? * 1. This is a simple way to support variable-length operations * 2. This adds "stability" to the input. * For example take the input "AbBcgDefg", where there is no separator and * Opcodes are capitalized. * Simply, by removing the first byte, we end up with a very different * sequence: * BbcGdefg... * By adding a separator, we avoid this problem: * Ab SEP Bcg SEP Defg -> B SEP Bcg SEP Defg * Since B uses two additional bytes as operands, the first "B" will be * ignored. The fuzzer actively tries to reduce inputs, so such unused * bytes are likely to be pruned, eventually. * * SEPARATOR is trivial for the fuzzer to discover when using ASan. Optionally, * SEPARATOR can be manually specified as a dictionary value (see libfuzzer's * -dict), though this should not be necessary. * * As a result, the stream of bytes is converted into a sequence of commands. * In a simplified example where SEPARATOR is 0xFF: * 00 01 02 FF 03 04 05 06 FF 01 FF ... * becomes this sequence of commands: * 00 01 02 -> op00 (0102) -> in (0102, 2) * 03 04 05 06 -> op03 (040506) -> write (040506, 3) * 01 -> op01 (-,0) -> out (-,0) * ... * * Note here that it is the job of the individual opcode functions to check * that enough data was provided. I.e. in the last command out (,0), out needs * to check that there is not enough data provided to select an address/value * for the operation. */ static void generic_fuzz(QTestState *s, const unsigned char *Data, size_t Size) { void (*ops[]) (QTestState *s, const unsigned char* , size_t) = { [OP_IN] = op_in, [OP_OUT] = op_out, [OP_READ] = op_read, [OP_WRITE] = op_write, [OP_PCI_READ] = op_pci_read, [OP_PCI_WRITE] = op_pci_write, [OP_DISABLE_PCI] = op_disable_pci, [OP_ADD_DMA_PATTERN] = op_add_dma_pattern, [OP_CLEAR_DMA_PATTERNS] = op_clear_dma_patterns, [OP_CLOCK_STEP] = op_clock_step, }; const unsigned char *cmd = Data; const unsigned char *nextcmd; size_t cmd_len; uint8_t op; if (fork() == 0) { /* * Sometimes the fuzzer will find inputs that take quite a long time to * process. Often times, these inputs do not result in new coverage. * Even if these inputs might be interesting, they can slow down the * fuzzer, overall. Set a timeout to avoid hurting performance, too much */ if (timeout) { struct sigaction sact; struct itimerval timer; sigemptyset(&sact.sa_mask); sact.sa_flags = SA_NODEFER; sact.sa_handler = handle_timeout; sigaction(SIGALRM, &sact, NULL); memset(&timer, 0, sizeof(timer)); timer.it_value.tv_sec = timeout / USEC_IN_SEC; timer.it_value.tv_usec = timeout % USEC_IN_SEC; setitimer(ITIMER_VIRTUAL, &timer, NULL); } op_clear_dma_patterns(s, NULL, 0); pci_disabled = false; while (cmd && Size) { /* Get the length until the next command or end of input */ nextcmd = memmem(cmd, Size, SEPARATOR, strlen(SEPARATOR)); cmd_len = nextcmd ? nextcmd - cmd : Size; if (cmd_len > 0) { /* Interpret the first byte of the command as an opcode */ op = *cmd % (sizeof(ops) / sizeof((ops)[0])); ops[op](s, cmd + 1, cmd_len - 1); /* Run the main loop */ flush_events(s); } /* Advance to the next command */ cmd = nextcmd ? nextcmd + sizeof(SEPARATOR) - 1 : nextcmd; Size = Size - (cmd_len + sizeof(SEPARATOR) - 1); g_array_set_size(dma_regions, 0); } _Exit(0); } else { flush_events(s); wait(0); } } static void usage(void) { printf("Please specify the following environment variables:\n"); printf("QEMU_FUZZ_ARGS= the command line arguments passed to qemu\n"); printf("QEMU_FUZZ_OBJECTS= " "a space separated list of QOM type names for objects to fuzz\n"); printf("Optionally: QEMU_AVOID_DOUBLE_FETCH= " "Try to avoid racy DMA double fetch bugs? %d by default\n", avoid_double_fetches); printf("Optionally: QEMU_FUZZ_TIMEOUT= Specify a custom timeout (us). " "0 to disable. %d by default\n", timeout); exit(0); } static int locate_fuzz_memory_regions(Object *child, void *opaque) { const char *name; MemoryRegion *mr; if (object_dynamic_cast(child, TYPE_MEMORY_REGION)) { mr = MEMORY_REGION(child); if ((memory_region_is_ram(mr) || memory_region_is_ram_device(mr) || memory_region_is_rom(mr)) == false) { name = object_get_canonical_path_component(child); /* * We don't want duplicate pointers to the same MemoryRegion, so * try to remove copies of the pointer, before adding it. */ g_hash_table_insert(fuzzable_memoryregions, mr, (gpointer)true); } } return 0; } static int locate_fuzz_objects(Object *child, void *opaque) { char *pattern = opaque; if (g_pattern_match_simple(pattern, object_get_typename(child))) { /* Find and save ptrs to any child MemoryRegions */ object_child_foreach_recursive(child, locate_fuzz_memory_regions, NULL); /* * We matched an object. If its a PCI device, store a pointer to it so * we can map BARs and fuzz its config space. */ if (object_dynamic_cast(OBJECT(child), TYPE_PCI_DEVICE)) { /* * Don't want duplicate pointers to the same PCIDevice, so remove * copies of the pointer, before adding it. */ g_ptr_array_remove_fast(fuzzable_pci_devices, PCI_DEVICE(child)); g_ptr_array_add(fuzzable_pci_devices, PCI_DEVICE(child)); } } else if (object_dynamic_cast(OBJECT(child), TYPE_MEMORY_REGION)) { if (g_pattern_match_simple(pattern, object_get_canonical_path_component(child))) { MemoryRegion *mr; mr = MEMORY_REGION(child); if ((memory_region_is_ram(mr) || memory_region_is_ram_device(mr) || memory_region_is_rom(mr)) == false) { g_hash_table_insert(fuzzable_memoryregions, mr, (gpointer)true); } } } return 0; } static void pci_enum(gpointer pcidev, gpointer bus) { PCIDevice *dev = pcidev; QPCIDevice *qdev; int i; qdev = qpci_device_find(bus, dev->devfn); g_assert(qdev != NULL); for (i = 0; i < 6; i++) { if (dev->io_regions[i].size) { qpci_iomap(qdev, i, NULL); } } qpci_device_enable(qdev); g_free(qdev); } static void generic_pre_fuzz(QTestState *s) { GHashTableIter iter; MemoryRegion *mr; QPCIBus *pcibus; char **result; if (!getenv("QEMU_FUZZ_OBJECTS")) { usage(); } if (getenv("QTEST_LOG")) { qtest_log_enabled = 1; } if (getenv("QEMU_AVOID_DOUBLE_FETCH")) { avoid_double_fetches = 1; } if (getenv("QEMU_FUZZ_TIMEOUT")) { timeout = g_ascii_strtoll(getenv("QEMU_FUZZ_TIMEOUT"), NULL, 0); } qts_global = s; /* * Create a special device that we can use to back DMA buffers at very * high memory addresses */ sparse_mem_mr = sparse_mem_init(0, UINT64_MAX); dma_regions = g_array_new(false, false, sizeof(address_range)); dma_patterns = g_array_new(false, false, sizeof(pattern)); fuzzable_memoryregions = g_hash_table_new(NULL, NULL); fuzzable_pci_devices = g_ptr_array_new(); result = g_strsplit(getenv("QEMU_FUZZ_OBJECTS"), " ", -1); for (int i = 0; result[i] != NULL; i++) { printf("Matching objects by name %s\n", result[i]); object_child_foreach_recursive(qdev_get_machine(), locate_fuzz_objects, result[i]); } g_strfreev(result); printf("This process will try to fuzz the following MemoryRegions:\n"); g_hash_table_iter_init(&iter, fuzzable_memoryregions); while (g_hash_table_iter_next(&iter, (gpointer)&mr, NULL)) { printf(" * %s (size %lx)\n", object_get_canonical_path_component(&(mr->parent_obj)), (uint64_t)mr->size); } if (!g_hash_table_size(fuzzable_memoryregions)) { printf("No fuzzable memory regions found...\n"); exit(1); } pcibus = qpci_new_pc(s, NULL); g_ptr_array_foreach(fuzzable_pci_devices, pci_enum, pcibus); qpci_free_pc(pcibus); counter_shm_init(); } /* * When libfuzzer gives us two inputs to combine, return a new input with the * following structure: * * Input 1 (data1) * SEPARATOR * Clear out the DMA Patterns * SEPARATOR * Disable the pci_read/write instructions * SEPARATOR * Input 2 (data2) * * The idea is to collate the core behaviors of the two inputs. * For example: * Input 1: maps a device's BARs, sets up three DMA patterns, and triggers * device functionality A * Input 2: maps a device's BARs, sets up one DMA pattern, and triggers device * functionality B * * This function attempts to produce an input that: * Ouptut: maps a device's BARs, set up three DMA patterns, triggers * functionality A device, replaces the DMA patterns with a single * patten, and triggers device functionality B. */ static size_t generic_fuzz_crossover(const uint8_t *data1, size_t size1, const uint8_t *data2, size_t size2, uint8_t *out, size_t max_out_size, unsigned int seed) { size_t copy_len = 0, size = 0; /* Check that we have enough space for data1 and at least part of data2 */ if (max_out_size <= size1 + strlen(SEPARATOR) * 3 + 2) { return 0; } /* Copy_Len in the first input */ copy_len = size1; memcpy(out + size, data1, copy_len); size += copy_len; max_out_size -= copy_len; /* Append a separator */ copy_len = strlen(SEPARATOR); memcpy(out + size, SEPARATOR, copy_len); size += copy_len; max_out_size -= copy_len; /* Clear out the DMA Patterns */ copy_len = 1; if (copy_len) { out[size] = OP_CLEAR_DMA_PATTERNS; } size += copy_len; max_out_size -= copy_len; /* Append a separator */ copy_len = strlen(SEPARATOR); memcpy(out + size, SEPARATOR, copy_len); size += copy_len; max_out_size -= copy_len; /* Disable PCI ops. Assume data1 took care of setting up PCI */ copy_len = 1; if (copy_len) { out[size] = OP_DISABLE_PCI; } size += copy_len; max_out_size -= copy_len; /* Append a separator */ copy_len = strlen(SEPARATOR); memcpy(out + size, SEPARATOR, copy_len); size += copy_len; max_out_size -= copy_len; /* Copy_Len over the second input */ copy_len = MIN(size2, max_out_size); memcpy(out + size, data2, copy_len); size += copy_len; max_out_size -= copy_len; return size; } static GString *generic_fuzz_cmdline(FuzzTarget *t) { GString *cmd_line = g_string_new(TARGET_NAME); if (!getenv("QEMU_FUZZ_ARGS")) { usage(); } g_string_append_printf(cmd_line, " -display none \ -machine accel=qtest, \ -m 512M %s ", getenv("QEMU_FUZZ_ARGS")); return cmd_line; } static GString *generic_fuzz_predefined_config_cmdline(FuzzTarget *t) { gchar *args; const generic_fuzz_config *config; g_assert(t->opaque); config = t->opaque; setenv("QEMU_AVOID_DOUBLE_FETCH", "1", 1); if (config->argfunc) { args = config->argfunc(); setenv("QEMU_FUZZ_ARGS", args, 1); g_free(args); } else { g_assert_nonnull(config->args); setenv("QEMU_FUZZ_ARGS", config->args, 1); } setenv("QEMU_FUZZ_OBJECTS", config->objects, 1); return generic_fuzz_cmdline(t); } static void register_generic_fuzz_targets(void) { fuzz_add_target(&(FuzzTarget){ .name = "generic-fuzz", .description = "Fuzz based on any qemu command-line args. ", .get_init_cmdline = generic_fuzz_cmdline, .pre_fuzz = generic_pre_fuzz, .fuzz = generic_fuzz, .crossover = generic_fuzz_crossover }); GString *name; const generic_fuzz_config *config; for (int i = 0; i < sizeof(predefined_configs) / sizeof(generic_fuzz_config); i++) { config = predefined_configs + i; name = g_string_new("generic-fuzz"); g_string_append_printf(name, "-%s", config->name); fuzz_add_target(&(FuzzTarget){ .name = name->str, .description = "Predefined generic-fuzz config.", .get_init_cmdline = generic_fuzz_predefined_config_cmdline, .pre_fuzz = generic_pre_fuzz, .fuzz = generic_fuzz, .crossover = generic_fuzz_crossover, .opaque = (void *)config }); } } fuzz_target_init(register_generic_fuzz_targets);