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// 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
#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
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