Use strerror_r(3) for the printf family %m.

There's TLS space used for unknown errno values, and a call to printf
shouldn't clobber that. No-one will ever hit this in real life, but
since it's easily fixed...

Bug: http://b/112776560
Test: ran tests
Change-Id: I8c2437f2e5214e652119791d4e162a197b049d5b

1 files changed, 2 insertions, 1 deletions

diff --git a/libc/stdio/vfwprintf.cpp b/libc/stdio/vfwprintf.cpp
index 19cce17e6..dd51eec4a 100644
--- a/libc/stdio/vfwprintf.cpp
+++ b/libc/stdio/vfwprintf.cpp
@@ -439,7 +439,8 @@ int FUNCTION_NAME(FILE* fp, const CHAR_TYPE* fmt0, va_list ap) {
         __fortify_fatal("%%n not allowed on Android");
       case 'm':
         free(convbuf);
-        convbuf = helpers::mbsconv(strerror(caller_errno), prec);
+        convbuf = helpers::mbsconv(strerror_r(caller_errno,
+                                              reinterpret_cast<char*>(buf), sizeof(buf)), prec);
         if (convbuf == nullptr) {
             fp->_flags |= __SERR;
             goto error;