diff options
| author | Dmitry Vyukov <dvyukov@google.com> | 2020-09-11 12:38:07 +0200 |
|---|---|---|
| committer | Dmitry Vyukov <dvyukov@google.com> | 2020-09-12 13:03:35 +0200 |
| commit | 7b0683780a0f5f05e602bb3fe9d97c66f2c956e4 (patch) | |
| tree | 930750ec88518252bc4281c81b9aad26acb7a194 /executor | |
| parent | c38fcca50dbf789b6524280b8cf32c65d4b4e5e4 (diff) | |
executor: detect gvisor
gvisor coverage is not in the range of linux kernel coverage.
So the coverage filter does not work. Detect if running under gvisor
and skip the coverage filter.
Diffstat (limited to 'executor')
| -rw-r--r-- | executor/executor_linux.h | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/executor/executor_linux.h b/executor/executor_linux.h index fce380561..26ce9ef52 100644 --- a/executor/executor_linux.h +++ b/executor/executor_linux.h @@ -50,6 +50,8 @@ typedef char kcov_remote_arg64_size[sizeof(kcov_remote_arg64) == 24 ? 1 : -1]; #define KCOV_SUBSYSTEM_MASK (0xffull << 56) #define KCOV_INSTANCE_MASK (0xffffffffull) +static bool is_gvisor; + static inline __u64 kcov_remote_handle(__u64 subsys, __u64 inst) { if (subsys & ~KCOV_SUBSYSTEM_MASK || inst & ~KCOV_INSTANCE_MASK) @@ -58,11 +60,13 @@ static inline __u64 kcov_remote_handle(__u64 subsys, __u64 inst) } static bool detect_kernel_bitness(); +static bool detect_gvisor(); static void os_init(int argc, char** argv, char* data, size_t data_size) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); is_kernel_64_bit = detect_kernel_bitness(); + is_gvisor = detect_gvisor(); // Surround the main data mapping with PROT_NONE pages to make virtual address layout more consistent // across different configurations (static/non-static build) and C repros. // One observed case before: executor had a mapping above the data mapping (output region), @@ -221,7 +225,7 @@ static bool cover_check(uint64 pc) { #if defined(__i386__) || defined(__x86_64__) // Text/modules range for x86_64. - return pc >= 0xffffffff80000000ull && pc < 0xffffffffff000000ull; + return is_gvisor || (pc >= 0xffffffff80000000ull && pc < 0xffffffffff000000ull); #else return true; #endif @@ -249,6 +253,15 @@ static bool detect_kernel_bitness() return wide; } +static bool detect_gvisor() +{ + char buf[64] = {}; + // 3 stands for undeclared SYSLOG_ACTION_READ_ALL. + syscall(__NR_syslog, 3, buf, sizeof(buf) - 1); + // This is a first line of gvisor dmesg. + return strstr(buf, "Starting gVisor"); +} + // One does not simply exit. // _exit can in fact fail. // syzkaller did manage to generate a seccomp filter that prohibits exit_group syscall. |