ta_dev_kit.mk: define ENABLE_MDBG when CFG_TEE_TA_MALLOC_DEBUG is set

In order to use the memory leak detection code, a user-mode TA needs
two things:
- A version of libutils.a that was built with malloc debug code. This
is taken care of by ta/ta.mk which sets ENABLE_MDBG=1 when
CFG_TEE_TA_MALLOC_DEBUG is 'y'.
- The proper declarations for mdbg_malloc(), mdbg_free(), mdbg_check()
etc. as well as the macro redefinitions for malloc(), free() etc. in
the header files when the TA is built. This patch adds the
missing definition of ENABLE_MDBG in ta/mk/ta_dev_kit.mk when
CFG_TEE_TA_MALLOC_DEBUG is 'y'.

In addition, the usage of CFG_TEE_TA_MALLOC_DEBUG and
CFG_TEE_CORE_MALLOC_DEBUG is better documented in mk/conf.mk.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/mk/config.mk b/mk/config.mk
index 1ffa20de..738b6d10 100644
--- a/mk/config.mk
+++ b/mk/config.mk
@@ -64,7 +64,16 @@ CFG_TEE_CORE_TA_TRACE ?= y
 # feature.
 CFG_TEE_CORE_USER_MEM_DEBUG ?= 1
 
-# If y, enable memory leak detection feature in bget memory allocator.
+# If y, enable the memory leak detection feature in the bget memory allocator.
+# When this feature is enabled, calling mdbg_check(1) will print a list of all
+# the currently allocated buffers and the location of the allocation (file and
+# line number).
+# Note: make sure the log level is high enough for the messages to show up on
+# the secure console! For instance:
+# - To debug user-mode (TA) allocations: build OP-TEE *and* the TA with:
+#   $ make CFG_TEE_TA_MALLOC_DEBUG=y CFG_TEE_TA_LOG_LEVEL=3
+# - To debug TEE core allocations: build OP-TEE with:
+#   $ make CFG_TEE_CORE_MALLOC_DEBUG=y CFG_TEE_CORE_LOG_LEVEL=3
 CFG_TEE_CORE_MALLOC_DEBUG ?= n
 CFG_TEE_TA_MALLOC_DEBUG ?= n