| // RUN: %clang_dfsan -fno-sanitize=dataflow -O2 -fPIE -DCALLBACKS -c %s -o %t-callbacks.o |
| // RUN: %clang_dfsan -fsanitize-ignorelist=%S/Inputs/flags_abilist.txt -O2 -mllvm -dfsan-conditional-callbacks %s %t-callbacks.o -o %t |
| // RUN: %run %t FooBarBaz 2>&1 | FileCheck %s |
| // |
| // REQUIRES: x86_64-target-arch |
| |
| #include <assert.h> |
| #include <sanitizer/dfsan_interface.h> |
| #include <signal.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #ifdef CALLBACKS |
| // Compile this code without DFSan to avoid recursive instrumentation. |
| |
| void my_dfsan_conditional_callback(dfsan_label Label, dfsan_origin Origin) { |
| assert(Label != 0); |
| assert(Origin == 0); |
| |
| static int Count = 0; |
| switch (Count++) { |
| case 0: |
| assert(Label == 1); |
| break; |
| case 1: |
| assert(Label == 4); |
| break; |
| default: |
| break; |
| } |
| |
| fprintf(stderr, "Label %u used as condition\n", Label); |
| } |
| |
| #else |
| // Compile this code with DFSan and -dfsan-conditional-callbacks to insert the |
| // callbacks. |
| |
| extern void my_dfsan_conditional_callback(dfsan_label Label, |
| dfsan_origin Origin); |
| |
| volatile int x = 0; |
| volatile int y = 1; |
| volatile int z = 0; |
| |
| void SignalHandler(int signo) { |
| assert(dfsan_get_label(x) == 0); |
| assert(dfsan_get_label(y) != 0); |
| assert(dfsan_get_label(z) != 0); |
| // Running the conditional callback from a signal handler is risky, |
| // because the code must be written with signal handler context in mind. |
| // Instead dfsan_get_labels_in_signal_conditional() will indicate labels |
| // used in conditions inside signal handlers. |
| // CHECK-NOT: Label 8 used as condition |
| if (z != 0) { |
| x = y; |
| } |
| } |
| |
| int main(int Argc, char *Argv[]) { |
| assert(Argc >= 1); |
| int unknown = (Argv[0][0] != 0) ? 1 : 0; |
| dfsan_set_label(1, &unknown, sizeof(unknown)); |
| |
| dfsan_set_conditional_callback(my_dfsan_conditional_callback); |
| |
| // CHECK: Label 1 used as condition |
| if (unknown) { |
| z = 42; |
| } |
| |
| assert(dfsan_get_labels_in_signal_conditional() == 0); |
| dfsan_set_label(4, (void *)&y, sizeof(y)); |
| dfsan_set_label(8, (void *)&z, sizeof(z)); |
| |
| struct sigaction sa = {}; |
| sa.sa_handler = SignalHandler; |
| int r = sigaction(SIGHUP, &sa, NULL); |
| assert(dfsan_get_label(r) == 0); |
| |
| kill(getpid(), SIGHUP); |
| signal(SIGHUP, SIG_DFL); |
| |
| assert(dfsan_get_labels_in_signal_conditional() == 8); |
| assert(x == 1); |
| // CHECK: Label 4 used as condition |
| if (x != 0) { |
| z = 123; |
| } |
| // Flush should clear the conditional signals seen. |
| dfsan_flush(); |
| assert(dfsan_get_labels_in_signal_conditional() == 0); |
| return 0; |
| } |
| |
| #endif // #ifdef CALLBACKS |