diff options
Diffstat (limited to 'tests/qtest/fuzz/generic_fuzz.c')
| -rw-r--r-- | tests/qtest/fuzz/generic_fuzz.c | 119 |
1 files changed, 27 insertions, 92 deletions
diff --git a/tests/qtest/fuzz/generic_fuzz.c b/tests/qtest/fuzz/generic_fuzz.c index 7326f68..c525d22 100644 --- a/tests/qtest/fuzz/generic_fuzz.c +++ b/tests/qtest/fuzz/generic_fuzz.c @@ -18,7 +18,6 @@ #include "tests/qtest/libqtest.h" #include "tests/qtest/libqos/pci-pc.h" #include "fuzz.h" -#include "fork_fuzz.h" #include "string.h" #include "exec/memory.h" #include "exec/ramblock.h" @@ -29,6 +28,8 @@ #include "generic_fuzz_configs.h" #include "hw/mem/sparse-mem.h" +static void pci_enum(gpointer pcidev, gpointer bus); + /* * SEPARATOR is used to separate "operations" in the fuzz input */ @@ -47,10 +48,10 @@ enum cmds { OP_CLOCK_STEP, }; -#define DEFAULT_TIMEOUT_US 100000 #define USEC_IN_SEC 1000000000 #define MAX_DMA_FILL_SIZE 0x10000 +#define MAX_TOTAL_DMA_SIZE 0x10000000 #define PCI_HOST_BRIDGE_CFG 0xcf8 #define PCI_HOST_BRIDGE_DATA 0xcfc @@ -60,9 +61,8 @@ typedef struct { 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; +size_t dma_bytes_written; MemoryRegion *sparse_mem_mr; @@ -196,6 +196,7 @@ void fuzz_dma_read_cb(size_t addr, size_t len, MemoryRegion *mr) */ if (dma_patterns->len == 0 || len == 0 + || dma_bytes_written + len > MAX_TOTAL_DMA_SIZE || (mr != current_machine->ram && mr != sparse_mem_mr)) { return; } @@ -268,6 +269,7 @@ void fuzz_dma_read_cb(size_t addr, size_t len, MemoryRegion *mr) fflush(stderr); } qtest_memwrite(qts_global, addr, buf, l); + dma_bytes_written += l; } len -= l; buf += l; @@ -589,30 +591,6 @@ 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 @@ -669,64 +647,33 @@ static void generic_fuzz(QTestState *s, const unsigned char *Data, size_t Size) size_t cmd_len; uint8_t op; - if (fork() == 0) { - struct sigaction sact; - struct itimerval timer; - sigset_t set; - /* - * 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 for each command to avoid hurting - * performance, too much - */ - if (timeout) { - - sigemptyset(&sact.sa_mask); - sact.sa_flags = SA_NODEFER; - sact.sa_handler = handle_timeout; - sigaction(SIGALRM, &sact, NULL); + op_clear_dma_patterns(s, NULL, 0); + pci_disabled = false; + dma_bytes_written = 0; - sigemptyset(&set); - sigaddset(&set, SIGALRM); - pthread_sigmask(SIG_UNBLOCK, &set, NULL); - - memset(&timer, 0, sizeof(timer)); - timer.it_value.tv_sec = timeout / USEC_IN_SEC; - timer.it_value.tv_usec = timeout % USEC_IN_SEC; - } - - op_clear_dma_patterns(s, NULL, 0); - pci_disabled = false; - - while (cmd && Size) { - /* Reset the timeout, each time we run a new command */ - if (timeout) { - setitimer(ITIMER_REAL, &timer, NULL); - } + QPCIBus *pcibus = qpci_new_pc(s, NULL); + g_ptr_array_foreach(fuzzable_pci_devices, pci_enum, pcibus); + qpci_free_pc(pcibus); - /* Get the length until the next command or end of input */ - nextcmd = memmem(cmd, Size, SEPARATOR, strlen(SEPARATOR)); - cmd_len = nextcmd ? nextcmd - cmd : Size; + 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); + 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); + /* Run the main loop */ + flush_events(s); } - _Exit(0); - } else { - flush_events(s); - wait(0); + /* 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); } + fuzz_reset(s); } static void usage(void) @@ -738,8 +685,6 @@ static void usage(void) 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); } @@ -825,7 +770,6 @@ static void generic_pre_fuzz(QTestState *s) { GHashTableIter iter; MemoryRegion *mr; - QPCIBus *pcibus; char **result; GString *name_pattern; @@ -838,9 +782,6 @@ static void generic_pre_fuzz(QTestState *s) 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; /* @@ -883,12 +824,6 @@ static void generic_pre_fuzz(QTestState *s) 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(); } /* |