[PATCH] malloc: Simplify implementation of __malloc_assert

[Florian Weimer]

It is prudent not to run too much code after detecting heap
corruption, and __fxprintf is really complex.  The line number
and file name do not carry much information, so it is not included
in the error message.  (__libc_message only supports %s formatting.)
The function name and assertion should provide some context.

Tested on i686-linux-gnu and x86_64-linux-gnu.  Also emulated the
__libc_message call using GDB, and it produced the expected output.

Thanks,
Florian
---
 malloc/malloc.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/malloc/malloc.c b/malloc/malloc.c
index 12908b8f97..bd3c76ed31 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -292,19 +292,14 @@
 # define __assert_fail(assertion, file, line, function)			\
 	 __malloc_assert(assertion, file, line, function)
 
-extern const char *__progname;
-
-static void
+_Noreturn static void
 __malloc_assert (const char *assertion, const char *file, unsigned int line,
 		 const char *function)
 {
-  (void) __fxprintf (NULL, "%s%s%s:%u: %s%sAssertion `%s' failed.\n",
-		     __progname, __progname[0] ? ": " : "",
-		     file, line,
-		     function ? function : "", function ? ": " : "",
-		     assertion);
-  fflush (stderr);
-  abort ();
+  __libc_message (do_abort, "\
+Fatal glibc error: malloc assertion failure in %s: %s\n",
+		  function, assertion);
+  __builtin_unreachable ();
 }
 #endif
 #endif