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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 16:44:12 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 16:44:12 +0000
commitcda5d340e78555d2542be9264137319c5308e798 (patch)
tree7bc11f3311859ceee697bba8b60a5cb79a03473b /lib/replace/tests/incoherent_mmap.c
parentInitial commit. (diff)
downloadtalloc-upstream.tar.xz
talloc-upstream.zip
Adding upstream version 2.4.2.upstream/2.4.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/replace/tests/incoherent_mmap.c')
-rw-r--r--lib/replace/tests/incoherent_mmap.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/lib/replace/tests/incoherent_mmap.c b/lib/replace/tests/incoherent_mmap.c
new file mode 100644
index 0000000..ee288fd
--- /dev/null
+++ b/lib/replace/tests/incoherent_mmap.c
@@ -0,0 +1,83 @@
+/* In OpenBSD, if you write to a file, another process doesn't see it
+ * in its mmap. Returns with exit status 0 if that is the case, 1 if
+ * it's coherent, and other if there's a problem. */
+#include <err.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#define DATA "coherent.mmap"
+
+int main(int argc, char *argv[])
+{
+ int tochild[2], toparent[2];
+ int fd;
+ volatile unsigned char *map;
+ unsigned char *page;
+ const char *fname = argv[1];
+ char c = 0;
+
+ if (pipe(tochild) != 0 || pipe(toparent) != 0)
+ err(2, "Creating pipe");
+
+ if (!fname)
+ fname = DATA;
+
+ fd = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0600);
+ if (fd < 0)
+ err(2, "opening %s", fname);
+ unlink(fname);
+
+ switch (fork()) {
+ case -1:
+ err(2, "Fork");
+ case 0:
+ close(tochild[1]);
+ close(toparent[0]);
+
+ /* Wait for parent to create file. */
+ if (read(tochild[0], &c, 1) != 1)
+ err(2, "reading from parent");
+
+ /* Alter first byte. */
+ pwrite(fd, &c, 1, 0);
+
+ if (write(toparent[1], &c, 1) != 1)
+ err(2, "writing to parent");
+ exit(0);
+
+ default:
+ close(tochild[0]);
+ close(toparent[1]);
+
+ /* Create a file and mmap it. */
+ page = malloc(getpagesize());
+ memset(page, 0x42, getpagesize());
+ if (write(fd, page, getpagesize()) != getpagesize())
+ err(2, "writing first page");
+ map = mmap(NULL, getpagesize(), PROT_READ|PROT_WRITE,
+ MAP_SHARED, fd, 0);
+ if (map == MAP_FAILED)
+ err(2, "mapping file");
+
+ if (*map != 0x42)
+ errx(2, "first byte isn't 0x42!");
+
+ /* Tell child to alter file. */
+ if (write(tochild[1], &c, 1) != 1)
+ err(2, "writing to child");
+
+ if (read(toparent[0], &c, 1) != 1)
+ err(2, "reading from child");
+
+ if (*map)
+ errx(0, "mmap incoherent: first byte isn't 0.");
+
+ exit(1);
+ }
+}