diff options
Diffstat (limited to 'malloc')
| -rw-r--r-- | malloc/Makefile | 2 | ||||
| -rw-r--r-- | malloc/malloc.c | 2 | ||||
| -rw-r--r-- | malloc/tst-malloc-stats-cancellation.c | 216 |
3 files changed, 219 insertions, 1 deletions
diff --git a/malloc/Makefile b/malloc/Makefile index 17873e67c4..7d54bad866 100644 --- a/malloc/Makefile +++ b/malloc/Makefile @@ -37,6 +37,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \ tst-malloc-tcache-leak \ tst-malloc_info \ tst-malloc-too-large \ + tst-malloc-stats-cancellation \ tests-static := \ tst-interpose-static-nothread \ @@ -96,6 +97,7 @@ $(objpfx)tst-malloc-backtrace: $(shared-thread-library) $(objpfx)tst-malloc-thread-exit: $(shared-thread-library) $(objpfx)tst-malloc-thread-fail: $(shared-thread-library) $(objpfx)tst-malloc-fork-deadlock: $(shared-thread-library) +$(objpfx)tst-malloc-stats-cancellation: $(shared-thread-library) # Export the __malloc_initialize_hook variable to libc.so. LDFLAGS-tst-mallocstate = -rdynamic diff --git a/malloc/malloc.c b/malloc/malloc.c index f8e7250f70..3224b3a899 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -5009,7 +5009,7 @@ __malloc_stats (void) fprintf (stderr, "max mmap regions = %10u\n", (unsigned int) mp_.max_n_mmaps); fprintf (stderr, "max mmap bytes = %10lu\n", (unsigned long) mp_.max_mmapped_mem); - ((_IO_FILE *) stderr)->_flags2 |= old_flags2; + ((_IO_FILE *) stderr)->_flags2 = old_flags2; _IO_funlockfile (stderr); } diff --git a/malloc/tst-malloc-stats-cancellation.c b/malloc/tst-malloc-stats-cancellation.c new file mode 100644 index 0000000000..9a8f475830 --- /dev/null +++ b/malloc/tst-malloc-stats-cancellation.c @@ -0,0 +1,216 @@ +/* Bug 22830: malloc_stats fails to re-enable cancellation on exit. + Copyright (C) 2018 Free Software Foundation. + Copying and distribution of this file, with or without modification, + are permitted in any medium without royalty provided the copyright + notice and this notice are preserved. This file is offered as-is, + without any warranty. */ + +#include <errno.h> +#include <stdio.h> +#include <string.h> + +#include <pthread.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <fcntl.h> +#include <unistd.h> + +#include <malloc.h> + +static void * +test_threadproc (void *gatep) +{ + /* When we are released from the barrier, there is a cancellation + request pending for this thread. N.B. pthread_barrier_wait is + not itself a cancellation point (oddly enough). */ + pthread_barrier_wait ((pthread_barrier_t *)gatep); + malloc_stats (); + fputs ("this call should trigger cancellation\n", stderr); + return 0; +} + +/* We cannot replace stderr with a memstream because writes to memstreams + do not trigger cancellation. Instead, main swaps out fd 2 to point to + a pipe, and this thread reads from the pipe and writes to a memstream + until EOF, then returns the data accumulated in the memstream. main + can't do that itself because, when the test thread gets cancelled, + it doesn't close the pipe. */ + +struct buffer_tp_args +{ + int ifd; + FILE *real_stderr; +}; + +static void * +buffer_threadproc (void *argp) +{ + struct buffer_tp_args *args = argp; + int ifd = args->ifd; + char block[BUFSIZ], *p; + ssize_t nread; + size_t nwritten; + + char *obuf = 0; + size_t obufsz = 0; + FILE *ofp = open_memstream (&obuf, &obufsz); + if (!ofp) + { + fprintf (args->real_stderr, + "buffer_threadproc: open_memstream: %s\n", strerror (errno)); + return 0; + } + + while ((nread = read (ifd, block, BUFSIZ)) > 0) + { + p = block; + do + { + nwritten = fwrite_unlocked (p, 1, nread, ofp); + if (nwritten == 0) + { + fprintf (args->real_stderr, + "buffer_threadproc: fwrite_unlocked: %s\n", + strerror (errno)); + return 0; + } + nread -= nwritten; + p += nwritten; + } + while (nread > 0); + } + if (nread == -1) + { + fprintf (args->real_stderr, "buffer_threadproc: read: %s\n", + strerror (errno)); + return 0; + } + close (ifd); + fclose (ofp); + return obuf; +} + + +int +main (void) +{ + int result = 0, err, real_stderr_fd, bufpipe[2]; + pthread_t t_thr, b_thr; + pthread_barrier_t gate; + void *rv; + FILE *real_stderr; + char *obuf; + void *obuf_v; + struct buffer_tp_args b_args; + + real_stderr_fd = dup (2); + if (real_stderr_fd == -1) + { + perror ("dup"); + return 2; + } + real_stderr = fdopen(real_stderr_fd, "w"); + if (!real_stderr) + { + perror ("fdopen"); + return 2; + } + if (setvbuf (real_stderr, 0, _IOLBF, 0)) + { + perror ("setvbuf(real_stderr)"); + return 2; + } + + if (pipe (bufpipe)) + { + perror ("pipe"); + return 2; + } + + /* Below this point, nobody other than the test_threadproc should use + the normal stderr. */ + if (dup2 (bufpipe[1], 2) == -1) + { + fprintf (real_stderr, "dup2: %s\n", strerror (errno)); + return 2; + } + close (bufpipe[1]); + + b_args.ifd = bufpipe[0]; + b_args.real_stderr = real_stderr; + err = pthread_create (&b_thr, 0, buffer_threadproc, &b_args); + if (err) + { + fprintf (real_stderr, "pthread_create(buffer_thr): %s\n", + strerror (err)); + return 2; + } + + err = pthread_barrier_init (&gate, 0, 2); + if (err) + { + fprintf (real_stderr, "pthread_barrier_init: %s\n", strerror (err)); + return 2; + } + + err = pthread_create (&t_thr, 0, test_threadproc, &gate); + if (err) + { + fprintf (real_stderr, "pthread_create(test_thr): %s\n", strerror (err)); + return 2; + } + + err = pthread_cancel (t_thr); + if (err) + { + fprintf (real_stderr, "pthread_cancel: %s\n", strerror (err)); + return 2; + } + + pthread_barrier_wait (&gate); /* cannot fail */ + + err = pthread_join (t_thr, &rv); + if (err) + { + fprintf (real_stderr, "pthread_join(test_thr): %s\n", strerror (err)); + return 2; + } + + /* Closing the normal stderr releases the buffer_threadproc from its + loop. */ + fclose (stderr); + err = pthread_join (b_thr, &obuf_v); + if (err) + { + fprintf (real_stderr, "pthread_join(buffer_thr): %s\n", strerror (err)); + return 2; + } + obuf = obuf_v; + if (obuf == 0) + return 2; /* error within buffer_threadproc, already reported */ + + if (rv != PTHREAD_CANCELED) + { + fputs ("FAIL: thread was not cancelled\n", real_stderr); + result = 1; + } + /* obuf should have received all of the text printed by malloc_stats, + but not the text printed by the final call to fputs. */ + if (!strstr (obuf, "max mmap bytes")) + { + fputs ("FAIL: malloc_stats output incomplete\n", real_stderr); + result = 1; + } + if (strstr (obuf, "this call should trigger cancellation")) + { + fputs ("FAIL: fputs produced output\n", real_stderr); + result = 1; + } + + if (result == 1) + { + fputs ("--- output from thread below ---\n", real_stderr); + fputs (obuf, real_stderr); + } + return result; +} |