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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2015-08-27 16:44:04 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.com>2015-08-28 10:42:07 -0300
commitd3573f61aca67a398de7eaa7593d3973cb5fd154 (patch)
treeae2d3f6feeb9c8109da990bbd9c93dcb0291e769 /posix
parent8c17cb1f6455c7a5fd6a1d05a2394129dbce012b (diff)
downloadglibc-d3573f61aca67a398de7eaa7593d3973cb5fd154.tar.gz
Fix wordsize-32 mmap offset for negative value (BZ#18877)
This patch fixes the default wordsize-32 mmap implementation offset calculation for negative values. Current code uses signed shift operation to calculate the multiple size to use with syscall and it is implementation defined. Change it to use a division base on mmap page size (default being as before, 4096). Tested on armv7hf. [BZ #18877] * posix/Makefile (tests): Add tst-mmap-offset. * posix/tst-mmap.c: New file. * sysdeps/unix/sysv/linux/generic/wordsize-32/mmap.c (__mmap): Fix offset calculation for negative values.
Diffstat (limited to 'posix')
-rw-r--r--posix/Makefile2
-rw-r--r--posix/tst-mmap-offset.c67
2 files changed, 68 insertions, 1 deletions
diff --git a/posix/Makefile b/posix/Makefile
index 15e8818787..39423a99b5 100644
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -64,7 +64,7 @@ routines := \
aux := init-posix environ
tests := tstgetopt testfnm runtests runptests \
tst-preadwrite tst-preadwrite64 test-vfork regexbug1 \
- tst-mmap tst-getaddrinfo tst-truncate \
+ tst-mmap tst-mmap-offset tst-getaddrinfo tst-truncate \
tst-truncate64 tst-fork tst-fnmatch tst-regexloc tst-dir \
tst-chmod bug-regex1 bug-regex2 bug-regex3 bug-regex4 \
tst-gnuglob tst-regex bug-regex5 bug-regex6 bug-regex7 \
diff --git a/posix/tst-mmap-offset.c b/posix/tst-mmap-offset.c
new file mode 100644
index 0000000000..2af8a671c3
--- /dev/null
+++ b/posix/tst-mmap-offset.c
@@ -0,0 +1,67 @@
+/* BZ #18877 mmap offset test.
+
+ Copyright (C) 2015 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+static int
+printmsg (int rc, const char *msg)
+{
+ printf ("%s failed: %m\n", msg);
+ return rc;
+}
+
+/* Check if negative offsets are handled correctly by mmap. */
+static int
+do_test (void)
+{
+ const int prot = PROT_READ | PROT_WRITE;
+ const int flags = MAP_SHARED;
+ const unsigned long length = 0x10000;
+ const unsigned long offset = 0xace00000;
+ const unsigned long size = offset + length;
+ void *addr;
+ int fd;
+ char fname[] = "tst-mmap-offset-XXXXXX";
+
+ fd = mkstemp64 (fname);
+ if (fd < 0)
+ return printmsg (1, "mkstemp");
+
+ if (unlink (fname))
+ return printmsg (1, "unlink");
+
+ if (ftruncate64 (fd, size))
+ return printmsg (0, "ftruncate64");
+
+ addr = mmap (NULL, length, prot, flags, fd, offset);
+ if (MAP_FAILED == addr)
+ return printmsg (1, "mmap");
+
+ /* This memcpy is likely to SIGBUS if mmap has messed up with offset. */
+ memcpy (addr, fname, sizeof (fname));
+
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"