Merge "Document various libc behavior changes."
am: 4486e57c7d

Change-Id: I84cbca01019da241f30315ec40c9d01a4c336129
diff --git a/docs/status.md b/docs/status.md
index 85f9b60..0cbcb47 100644
--- a/docs/status.md
+++ b/docs/status.md
@@ -49,6 +49,11 @@
   * `popen` now always uses `O_CLOEXEC`, not just with the `e` extension
   * Bug fixes to handling of UTF-8 U+fffe/U+ffff and code points above U+10ffff
   * `aligned_alloc` correctly verifies that `size` is a multiple of `alignment`
+  * Using `%n` with the printf family is now reported as a FORTIFY failure.
+    Previous versions of Android would ignore the `%n` but not consume the
+    corresponding pointer argument, leading to obscure errors. The scanf family
+    is unchanged.
+  * [fdsan](fdsan.md) detects common file descriptor errors at runtime.
 
 New libc functions in P (API level 28):
   * `aligned_alloc`
@@ -72,6 +77,10 @@
   * `%C` and `%S` support in the printf family (previously only the wprintf family supported these)
   * `%mc`/`%ms`/`%m[` support in the scanf family
   * `%s` support in strptime (strftime already supported it)
+  * Using a `pthread_mutex_t` after it's been destroyed will be detected at
+    runtime and reported as a FORTIFY failure.
+  * Passing a null `FILE*` or `DIR*` to libc is now detected at runtime and
+    reported as a FORTIFY failure.
 
 New libc functions in O (API level 26):
   * `sendto` FORTIFY support
@@ -96,6 +105,11 @@
   * `strtod_l`/`strtof_l`/`strtol_l`/`strtoul_l`
   * <wctype.h> `towctrans`/`towctrans_l`/`wctrans`/`wctrans_l`
 
+New libc behavior in O (API level 26):
+  * Passing an invalid `pthread_t` to libc is now detected at runtime and
+    reported as a FORTIFY failure. Most commonly this is a result of confusing
+    `pthread_t` and `pid_t`.
+
 New libc functions in N (API level 24):
   * more FORTIFY support functions (`fread`/`fwrite`/`getcwd`/`pwrite`/`write`)
   * all remaining `_FILE_OFFSET_BITS=64` functions, completing `_FILE_OFFSET_BITS=64` support in bionic (8)
@@ -108,6 +122,9 @@
   * GNU extensions `fileno_unlocked`/`strchrnul`
   * 32-bit `prlimit`
 
+New libc behavior in N (API level 24):
+  * `sem_wait` now returns EINTR when interrupted by a signal.
+
 New libc functions in M (API level 23):
   * <dirent.h> `telldir`, `seekdir`.
   * <malloc.h> `malloc_info`.