diff options
| -rw-r--r-- | compiler-rt/lib/lsan/lsan_common.cc | 13 | ||||
| -rw-r--r-- | compiler-rt/test/lsan/TestCases/guard-page.c | 60 |
2 files changed, 71 insertions, 2 deletions
diff --git a/compiler-rt/lib/lsan/lsan_common.cc b/compiler-rt/lib/lsan/lsan_common.cc index 0385c37ac51..e88853cab05 100644 --- a/compiler-rt/lib/lsan/lsan_common.cc +++ b/compiler-rt/lib/lsan/lsan_common.cc @@ -221,9 +221,18 @@ static void ProcessThreads(SuspendedThreadsList const &suspended_threads, LOG_THREADS("Stack at %p-%p (SP = %p).\n", stack_begin, stack_end, sp); if (sp < stack_begin || sp >= stack_end) { // SP is outside the recorded stack range (e.g. the thread is running a - // signal handler on alternate stack). Again, consider the entire stack - // range to be reachable. + // signal handler on alternate stack, or swapcontext was used). + // Again, consider the entire stack range to be reachable. LOG_THREADS("WARNING: stack pointer not in stack range.\n"); + uptr page_size = GetPageSizeCached(); + int skipped = 0; + while (stack_begin < stack_end && + !IsAccessibleMemoryRange(stack_begin, 1)) { + skipped++; + stack_begin += page_size; + } + LOG_THREADS("Skipped %d guard page(s) to obtain stack %p-%p.\n", + skipped, stack_begin, stack_end); } else { // Shrink the stack range to ignore out-of-scope values. stack_begin = sp; diff --git a/compiler-rt/test/lsan/TestCases/guard-page.c b/compiler-rt/test/lsan/TestCases/guard-page.c new file mode 100644 index 00000000000..5c70a9f08ac --- /dev/null +++ b/compiler-rt/test/lsan/TestCases/guard-page.c @@ -0,0 +1,60 @@ +// Check that if LSan finds that SP doesn't point into thread stack (e.g. +// if swapcontext is used), LSan will not hit the guard page. +// RUN: %clang_lsan %s -o %t && %run %t +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <pthread.h> +#include <ucontext.h> + +pthread_cond_t cond = PTHREAD_COND_INITIALIZER; +pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; +int ctxfunc_started = 0; + +static void die(const char* msg, int err) { + if (err == 0) + err = errno; + fprintf(stderr, "%s: %s\n", msg, strerror(err)); + exit(EXIT_FAILURE); +} + +static void ctxfunc() { + pthread_mutex_lock(&mutex); + ctxfunc_started = 1; + pthread_cond_signal(&cond); + pthread_mutex_unlock(&mutex); + // Leave this context alive when the program exits. + for (;;); +} + +static void* thread(void* arg) { + (void)arg; + ucontext_t ctx; + void* stack; + + if (getcontext(&ctx) < 0) + die("getcontext", 0); + stack = malloc(1 << 10); + if (stack == NULL) + die("malloc", 0); + ctx.uc_stack.ss_sp = stack; + ctx.uc_stack.ss_size = 1 << 10; + makecontext(&ctx, ctxfunc, 0); + setcontext(&ctx); + die("setcontext", 0); + return NULL; +} + +int main() { + pthread_t tid; + int i; + + pthread_mutex_lock(&mutex); + i = pthread_create(&tid, NULL, thread, NULL); + if (i != 0) + die("pthread_create", i); + while (!ctxfunc_started) pthread_cond_wait(&cond, &mutex); + pthread_mutex_unlock(&mutex); + return 0; +} |
