Update malloc tracing utility.

Change head pointer to be total calls; adjust users to modulo after
incrementing.

Use mmap() instead of sbrk().

Split environment variables so count and file can be specified.

Export trace hooks so mtrace-ctl can be built against libc.so.

Allow NULL to be passed to __mtrace_get_trace_buffer.

Add some error handling to mtrace-ctl.

1 files changed, 4 insertions, 0 deletions

diff --git a/malloc/Versions b/malloc/Versions
index f3c3d8a093..43cb90938a 100644
--- a/malloc/Versions
+++ b/malloc/Versions
@@ -72,5 +72,9 @@ libc {
     __libc_scratch_buffer_grow;
     __libc_scratch_buffer_grow_preserve;
     __libc_scratch_buffer_set_array_size;
+
+    # malloc trace hooks for mtrace-ctl
+    __malloc_set_trace_buffer;
+    __malloc_get_trace_buffer;
   }
 }