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1// RUN: %clang_dfsan -fno-sanitize=dataflow -O2 -fPIE -DCALLBACKS -c %s -o %t-callbacks.o2// RUN: %clang_dfsan -fsanitize-ignorelist=%S/Inputs/flags_abilist.txt -O2 -mllvm -dfsan-conditional-callbacks %s %t-callbacks.o -o %t3// RUN: %run %t FooBarBaz 2>&1 | FileCheck %s4 5#include <assert.h>6#include <sanitizer/dfsan_interface.h>7#include <signal.h>8#include <stdio.h>9#include <string.h>10#include <sys/types.h>11#include <unistd.h>12 13#ifdef CALLBACKS14// Compile this code without DFSan to avoid recursive instrumentation.15 16void my_dfsan_conditional_callback(dfsan_label Label, dfsan_origin Origin) {17 assert(Label != 0);18 assert(Origin == 0);19 20 static int Count = 0;21 switch (Count++) {22 case 0:23 assert(Label == 1);24 break;25 case 1:26 assert(Label == 4);27 break;28 default:29 break;30 }31 32 fprintf(stderr, "Label %u used as condition\n", Label);33}34 35#else36// Compile this code with DFSan and -dfsan-conditional-callbacks to insert the37// callbacks.38 39extern void my_dfsan_conditional_callback(dfsan_label Label,40 dfsan_origin Origin);41 42volatile int x = 0;43volatile int y = 1;44volatile int z = 0;45 46void SignalHandler(int signo) {47 assert(dfsan_get_label(x) == 0);48 assert(dfsan_get_label(y) != 0);49 assert(dfsan_get_label(z) != 0);50 // Running the conditional callback from a signal handler is risky,51 // because the code must be written with signal handler context in mind.52 // Instead dfsan_get_labels_in_signal_conditional() will indicate labels53 // used in conditions inside signal handlers.54 // CHECK-NOT: Label 8 used as condition55 if (z != 0) {56 x = y;57 }58}59 60int main(int Argc, char *Argv[]) {61 assert(Argc >= 1);62 int unknown = (Argv[0][0] != 0) ? 1 : 0;63 dfsan_set_label(1, &unknown, sizeof(unknown));64 65 dfsan_set_conditional_callback(my_dfsan_conditional_callback);66 67 // CHECK: Label 1 used as condition68 if (unknown) {69 z = 42;70 }71 72 assert(dfsan_get_labels_in_signal_conditional() == 0);73 dfsan_set_label(4, (void *)&y, sizeof(y));74 dfsan_set_label(8, (void *)&z, sizeof(z));75 76 struct sigaction sa = {};77 sa.sa_handler = SignalHandler;78 int r = sigaction(SIGHUP, &sa, NULL);79 assert(dfsan_get_label(r) == 0);80 81 kill(getpid(), SIGHUP);82 signal(SIGHUP, SIG_DFL);83 84 assert(dfsan_get_labels_in_signal_conditional() == 8);85 assert(x == 1);86 // CHECK: Label 4 used as condition87 if (x != 0) {88 z = 123;89 }90 // Flush should clear the conditional signals seen.91 dfsan_flush();92 assert(dfsan_get_labels_in_signal_conditional() == 0);93 return 0;94}95 96#endif // #ifdef CALLBACKS97