[dpdk-dev] [PATCH v3] mk: add support for UBSAN

[Harman Kalra <hkalra@marvell.com>]

UndefinedBehaviorSanitizer (UBSan) is a fast undefined behavior
detector. UBSan modifies the program at compile-time to catch
various kinds of undefined behavior during program execution.

This patch introduces support for UBSan to the DPDK.

See: doc/guides/prog_guide/ubsan.rst for more information.

Signed-off-by: Harman Kalra <hkalra@marvell.com>
---
V2:
* Addressed review comment regarding combining two
ifeq into one.

V3:
* Added version change logs.

 config/common_base                     |   6 ++
 config/meson.build                     |  15 ++++
 doc/guides/prog_guide/index.rst        |   1 +
 doc/guides/prog_guide/ubsan.rst        | 112 +++++++++++++++++++++++++
 doc/guides/rel_notes/release_19_11.rst |   7 ++
 meson_options.txt                      |   2 +
 mk/rte.app.mk                          |   8 ++
 mk/rte.lib.mk                          |  12 +++
 mk/toolchain/clang/rte.vars.mk         |   4 +
 mk/toolchain/gcc/rte.vars.mk           |   8 ++
 10 files changed, 175 insertions(+)
 create mode 100644 doc/guides/prog_guide/ubsan.rst

diff --git a/config/common_base b/config/common_base
index 914277856..f1bb3e0b2 100644
--- a/config/common_base
+++ b/config/common_base
@@ -1098,3 +1098,9 @@ CONFIG_RTE_APP_CRYPTO_PERF=y
 # Compile the eventdev application
 #
 CONFIG_RTE_APP_EVENTDEV=y
+
+#
+# Enable undefined behavior sanitizer
+#
+CONFIG_RTE_UBSAN=n
+CONFIG_RTE_UBSAN_SANITIZE_ALL=n
diff --git a/config/meson.build b/config/meson.build
index 2b1cb92e7..a43c23f50 100644
--- a/config/meson.build
+++ b/config/meson.build
@@ -238,3 +238,18 @@ if get_option('b_lto')
 		add_project_link_arguments('-Wno-lto-type-mismatch', language: 'c')
 	endif
 endif
+
+# enable ubsan
+if get_option('enable_ubsan')
+	if cc.has_argument('-fsanitize=undefined')
+		ubsan_dep = cc.find_library('libubsan', required: false)
+		if ubsan_dep.found()
+			add_project_arguments('-fsanitize=undefined', language: 'c')
+			add_project_link_arguments('-fsanitize=undefined', language: 'c')
+		else
+			message('libubsan not found, UBSAN cannot be enabled')
+		endif
+	else
+		message('gcc version does not support UBSAN')
+	endif
+endif
diff --git a/doc/guides/prog_guide/index.rst b/doc/guides/prog_guide/index.rst
index dc4851c57..911b82a41 100644
--- a/doc/guides/prog_guide/index.rst
+++ b/doc/guides/prog_guide/index.rst
@@ -67,4 +67,5 @@ Programmer's Guide
     writing_efficient_code
     lto
     profile_app
+    ubsan
     glossary
diff --git a/doc/guides/prog_guide/ubsan.rst b/doc/guides/prog_guide/ubsan.rst
new file mode 100644
index 000000000..cb19f3bd9
--- /dev/null
+++ b/doc/guides/prog_guide/ubsan.rst
@@ -0,0 +1,112 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2019 Marvell International Ltd.
+
+The Undefined Behavior Sanitizer - UBSan
+========================================
+
+UndefinedBehaviorSanitizer (UBSan) is a runtime undefined behavior detector.
+UBSan uses compile-time instrumentation and modifies the program by adding
+some stubs which perform certain checks before operations that might cause
+undefined behaviour. If some UB detected, respective _UBSan_handle_* handlers
+(which are defined in libUBSan library) are called to prints the error message.
+
+Some examples of undefined behaviour checks:
+
+* Misaligned memory access
+* Signed integer overflow
+* Load from/store to an object with insufficient space.
+* Integer divide by zero as well as INT_MIN / -1 division
+* Out-of-bounds memory accesses.
+* Null argument declared with nonnull attribute, returned null from function
+  which never returns null, null ptr dereference
+* Variable size array with non-positive length
+
+GCC supports this feature since 4.9, however GCC 5.0 onwards has many more
+checkers implemented.
+
+Example UBSan error
+--------------------
+
+Following error was reported when UBSan was enabled:
+
+.. code-block:: console
+
+    drivers/net/octeontx2/otx2_stats.c:82:26: runtime error: left shift of
+    1 by 31 places cannot be represented in type 'int'
+
+Code responsible for this error:
+
+.. code-block:: c
+
+    if (dev->txmap[i] & (1 << 31)) {
+
+To fix this error:
+
+.. code-block:: c
+
+    if (dev->txmap[i] & (1U << 31)) {
+
+Usage
+-----
+
+make build
+^^^^^^^^^^
+
+To enable UBSan, enable following configuration:
+
+.. code-block:: console
+
+    CONFIG_RTE_UBSAN=y
+
+UBSan framework supports three modes:
+
+1. Enable UBSan on the entire DPDK source code - set following configuration:
+
+.. code-block:: console
+
+    CONFIG_RTE_UBSAN_SANITIZE_ALL=y
+
+2. Enable UBSan on a particular library or PMD - add the following line to the
+   respective Makefile of the library or PMD
+   (make sure ``CONFIG_RTE_UBSAN_SANITIZE_ALL=n``). This will instrument only
+   the library or PMD and not the entire repository.
+
+.. code-block:: console
+
+    UBSAN_SANITIZE := y
+
+3. Disable UBSan for a particular library or PMD - add the following line to
+   the respective Makefile of the library or PMD. Make sure
+   ``CONFIG_RTE_UBSAN_SANITIZE_ALL=y`` config is set. This will instrument
+   entire DPDK repository but not this specific library or PMD.
+
+.. code-block:: console
+
+    UBSAN_SANITIZE := n
+
+.. Note::
+
+  Standard DPDK applications like test, testpmd, etc. cannot be
+  chosen explicitly for UBSan check, like libraries or PMD. The reason is,
+  say UBSan is enabled for library X, and ``UBSAN_SANITIZE=y`` is not added
+  in Makefile of app Y which uses X APIs. This will lead to undefined
+  reference to _UBSan_handle_* handlers as Y is not compiled with UBSan flags.
+  Hence UBSan check is enabled for all standard DPDK applications as soon as
+  ``CONFIG_RTE_UBSAN=y`` is set.
+
+meson build
+^^^^^^^^^^^
+
+To enable UBSan in meson build system, use following meson build command:
+
+**Example usage:**
+
+.. code-block:: console
+
+ meson build -Denable_ubsan=true
+ ninja -C build
+
+.. Note::
+
+  Meson build works only in one mode i.e. UBSan can be enabled for
+  the entire DPDK sources and not individual libraries or PMD, like make build.
diff --git a/doc/guides/rel_notes/release_19_11.rst b/doc/guides/rel_notes/release_19_11.rst
index c0045a91f..61fd1bcc2 100644
--- a/doc/guides/rel_notes/release_19_11.rst
+++ b/doc/guides/rel_notes/release_19_11.rst
@@ -294,6 +294,13 @@ New Features
 
   See :doc:`../prog_guide/lto` for more information:
 
+* **Added Undefined Behavior Sanitizer framework.**
+
+  UBSan is a fast runtime undefined behavior detector which uses compile-time
+  instrumentation and modifies the program by adding some stubs that perform
+  certain checks before operations that might cause undefined behavior.
+
+  See :doc:`../prog_guide/ubsan` for more information:
 
 
 Removed Items
diff --git a/meson_options.txt b/meson_options.txt
index 89650b0e9..f3b42d2b1 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -10,6 +10,8 @@ option('enable_docs', type: 'boolean', value: false,
 	description: 'build documentation')
 option('enable_kmods', type: 'boolean', value: true,
 	description: 'build kernel modules')
+option('enable_ubsan', type: 'boolean', value: false,
+	description: 'Enables undefined behavior sanitizer')
 option('examples', type: 'string', value: '',
 	description: 'Comma-separated list of examples to build by default')
 option('flexran_sdk', type: 'string', value: '',
diff --git a/mk/rte.app.mk b/mk/rte.app.mk
index 683e3a4e3..1304227cf 100644
--- a/mk/rte.app.mk
+++ b/mk/rte.app.mk
@@ -385,6 +385,14 @@ endif
 
 MAPFLAGS = -Map=$@.map --cref
 
+#
+# If UBSAN is enabled, all application will be compiled with
+# '-fsanitize=undefined' flag
+#
+ifeq ($(CONFIG_RTE_UBSAN)$(UBSAN_ENABLE),yy)
+CFLAGS += -fsanitize=undefined
+endif
+
 .PHONY: all
 all: install
 
diff --git a/mk/rte.lib.mk b/mk/rte.lib.mk
index 4df8849a0..33f5746c8 100644
--- a/mk/rte.lib.mk
+++ b/mk/rte.lib.mk
@@ -29,6 +29,18 @@ CPU_LDFLAGS += --version-script=$(SRCDIR)/$(EXPORT_MAP)
 endif
 endif
 
+#
+# If UBSAN is enabled, lib to undergo check can be chosen
+# by setting UBSAN_SANITIZE=y in respective lib Makefile
+# else set CONFIG_RTE_UBSAN_SANITIZE_ALL=y to enforce check
+# on entire repo.
+#
+ifeq ($(CONFIG_RTE_UBSAN),y)
+ifeq ($(UBSAN_ENABLE),y)
+CFLAGS += $(if $(patsubst %n,,$(CONFIG_RTE_UBSAN_SANITIZE_ALL)$(UBSAN_SANITIZE)) \
+		, -fsanitize=undefined)
+endif
+endif
 
 _BUILD = $(LIB)
 PREINSTALL = $(SYMLINK-FILES-y)
diff --git a/mk/toolchain/clang/rte.vars.mk b/mk/toolchain/clang/rte.vars.mk
index 3c49dc568..623780106 100644
--- a/mk/toolchain/clang/rte.vars.mk
+++ b/mk/toolchain/clang/rte.vars.mk
@@ -56,5 +56,9 @@ ifeq ($(shell test $(CLANG_MAJOR_VERSION) -ge 4 && echo 1), 1)
 WERROR_FLAGS += -Wno-address-of-packed-member
 endif
 
+ifeq ($(CONFIG_RTE_UBSAN),y)
+UBSAN_ENABLE := y
+endif
+
 export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
 export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
index 9fc704193..43e7d139b 100644
--- a/mk/toolchain/gcc/rte.vars.mk
+++ b/mk/toolchain/gcc/rte.vars.mk
@@ -102,5 +102,13 @@ endif
 # disable packed member unalign warnings
 WERROR_FLAGS += -Wno-address-of-packed-member
 
+ifeq ($(CONFIG_RTE_UBSAN),y)
+ifeq ($(shell test $(GCC_VERSION) -lt 49 && echo 1), 1)
+$(warning UBSAN not supported gcc < 4.9)
+else
+UBSAN_ENABLE = y
+endif
+endif
+
 export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
 export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
-- 
2.18.0