diff options
Diffstat (limited to 'executor/executor.cc')
| -rw-r--r-- | executor/executor.cc | 92 |
1 files changed, 65 insertions, 27 deletions
diff --git a/executor/executor.cc b/executor/executor.cc index 52275b185..c49f6e248 100644 --- a/executor/executor.cc +++ b/executor/executor.cc @@ -11,6 +11,7 @@ #include <linux/futex.h> #include <linux/reboot.h> #include <pthread.h> +#include <setjmp.h> #include <signal.h> #include <stdarg.h> #include <stddef.h> @@ -120,6 +121,9 @@ struct thread_t { thread_t threads[kMaxThreads]; char sandbox_stack[1 << 20]; +int skip_segv; +jmp_buf segv_env; + __attribute__((noreturn)) void fail(const char* msg, ...); __attribute__((noreturn)) void error(const char* msg, ...); __attribute__((noreturn)) void exitf(const char* msg, ...); @@ -150,6 +154,7 @@ void cover_enable(thread_t* th); void cover_reset(thread_t* th); uint64_t cover_read(thread_t* th); uint64_t cover_dedup(thread_t* th, uint64_t n); +void handle_segv(int sig, siginfo_t* info, void* uctx); int main(int argc, char** argv) { @@ -195,6 +200,12 @@ int main(int argc, char** argv) syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handle_segv; + sa.sa_flags = SA_NODEFER | SA_SIGINFO; + sigaction(SIGSEGV, &sa, NULL); + sigaction(SIGBUS, &sa, NULL); + int pid = -1; switch (flag_sandbox) { case sandbox_none: @@ -450,7 +461,11 @@ retry: break; } case arg_data: { - memcpy(addr, input_pos, size); + __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); + if (_setjmp(segv_env) == 0) { + memcpy(addr, input_pos, size); + } + __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); // Read out the data. for (uint64_t i = 0; i < (size + 7) / 8; i++) read_input(&input_pos); @@ -832,40 +847,63 @@ uint64_t cover_dedup(thread_t* th, uint64_t n) return w; } +void handle_segv(int sig, siginfo_t* info, void* uctx) +{ + if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED)) { + debug("caught signal %d during copyin/copyout, ignoring\n", sig); + _longjmp(segv_env, 1); + } + exitf("caught signal %d, exiting", sig); +} + void copyin(char* addr, uint64_t val, uint64_t size) { - switch (size) { - case 1: - *(uint8_t*)addr = val; - break; - case 2: - *(uint16_t*)addr = val; - break; - case 4: - *(uint32_t*)addr = val; - break; - case 8: - *(uint64_t*)addr = val; - break; - default: - fail("copyin: bad argument size %lu", size); + __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); + if (_setjmp(segv_env) == 0) { + switch (size) { + case 1: + *(uint8_t*)addr = val; + break; + case 2: + *(uint16_t*)addr = val; + break; + case 4: + *(uint32_t*)addr = val; + break; + case 8: + *(uint64_t*)addr = val; + break; + default: + fail("copyin: bad argument size %lu", size); + } } + __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); } uint64_t copyout(char* addr, uint64_t size) { - switch (size) { - case 1: - return *(uint8_t*)addr; - case 2: - return *(uint16_t*)addr; - case 4: - return *(uint32_t*)addr; - case 8: - return *(uint64_t*)addr; - default: - fail("copyout: bad argument size %lu", size); + uint64_t res = default_value; + __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); + if (_setjmp(segv_env) == 0) { + switch (size) { + case 1: + res = *(uint8_t*)addr; + break; + case 2: + res = *(uint16_t*)addr; + break; + case 4: + res = *(uint32_t*)addr; + break; + case 8: + res = *(uint64_t*)addr; + break; + default: + fail("copyout: bad argument size %lu", size); + } } + __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); + return res; } uint64_t read_arg(uint64_t** input_posp) |