diff options
Diffstat (limited to 'executor/executor.cc')
| -rw-r--r-- | executor/executor.cc | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/executor/executor.cc b/executor/executor.cc index e4034310d..5f19c079f 100644 --- a/executor/executor.cc +++ b/executor/executor.cc @@ -67,7 +67,6 @@ typedef unsigned char uint8; // Some common_OS.h files know about this constant for RLIMIT_NOFILE. const int kMaxFd = 250; const int kMaxThreads = 32; -const int kPreMmapCoverThreads = 3; // the number of kcov instances to mmap during init const int kInPipeFd = kMaxFd - 1; // remapped from stdin const int kOutPipeFd = kMaxFd - 2; // remapped from stdout const int kCoverFd = kOutPipeFd - kMaxThreads; @@ -76,6 +75,11 @@ const int kMaxArgs = 9; const int kCoverSize = 256 << 10; const int kFailStatus = 67; +// Two approaches of dealing with kcov memory. +const int kCoverOptimizedCount = 12; // the number of kcov instances to be opened inside main() +const int kCoverOptimizedPreMmap = 3; // this many will be mmapped inside main(), others - when needed. +const int kCoverDefaultCount = 5; // otherwise we only init kcov instances inside main() + // Logical error (e.g. invalid input program), use as an assert() alternative. // If such error happens 10+ times in a row, it will be detected as a bug by syz-fuzzer. // syz-fuzzer will fail and syz-manager will create a bug for this. @@ -167,6 +171,7 @@ static bool flag_close_fds; static bool flag_devlink_pci; static bool flag_vhci_injection; static bool flag_wifi; +static bool flag_delay_kcov_mmap; static bool flag_collect_cover; static bool flag_dedup_cover; @@ -469,10 +474,17 @@ int main(int argc, char** argv) receive_execute(); #endif if (flag_coverage) { - for (int i = 0; i < kMaxThreads; i++) { + int create_count = kCoverDefaultCount, mmap_count = create_count; + if (flag_delay_kcov_mmap) { + create_count = kCoverOptimizedCount; + mmap_count = kCoverOptimizedPreMmap; + } + if (create_count > kMaxThreads) + create_count = kMaxThreads; + for (int i = 0; i < create_count; i++) { threads[i].cov.fd = kCoverFd + i; cover_open(&threads[i].cov, false); - if (i < kPreMmapCoverThreads) { + if (i < mmap_count) { // Pre-mmap coverage collection for some threads. This should be enough for almost // all programs, for the remaning few ones coverage will be set up when it's needed. thread_mmap_cover(&threads[i]); @@ -600,6 +612,7 @@ void parse_env_flags(uint64 flags) flag_devlink_pci = flags & (1 << 11); flag_vhci_injection = flags & (1 << 12); flag_wifi = flags & (1 << 13); + flag_delay_kcov_mmap = flags & (1 << 14); } #if SYZ_EXECUTOR_USES_FORK_SERVER @@ -1193,8 +1206,11 @@ void thread_create(thread_t* th, int id, bool need_coverage) th->executing = false; // Lazily set up coverage collection. // It is assumed that actually it's already initialized - with a few rare exceptions. - if (need_coverage) + if (need_coverage) { + if (!th->cov.fd) + fail("out of opened kcov threads"); thread_mmap_cover(th); + } event_init(&th->ready); event_init(&th->done); event_set(&th->done); @@ -1206,6 +1222,8 @@ void thread_mmap_cover(thread_t* th) { if (th->cov.data != NULL) return; + if (!flag_delay_kcov_mmap) + fail("out of mmapped kcov threads"); cover_mmap(&th->cov); cover_protect(&th->cov); } |