cmake: Enable undefined behavior sanitizer on all targets

GCC and Clang support the undefined behavior sanitizer in any
configuration, the only restriction is that if you want to get nice
messages printed, then you need the ubsan library routines which are only
present for posix architecture or when using picolibc.

This patch adds three new compiler properties:

 * sanitizer_undefined. Enables the undefined behavior sanitizer.
 * sanitizer_undefined_library. Calls ubsan library routines on fault.
 * sanitizer_undefined_trap. Invokes __builtin_trap() on fault.

Overhead for using the trapping sanitizer is fairly low and should be
considered for use in CI once all of the undefined behavior faults in
Zephyr are fixed.

Signed-off-by: Keith Packard <keithp@keithp.com>

CMakeLists.txt

@@ -344,6 +344,18 @@ if (CONFIG_PICOLIBC AND NOT CONFIG_PICOLIBC_IO_FLOAT)
   zephyr_compile_options($<$<COMPILE_LANGUAGE:C>:$<TARGET_PROPERTY:compiler,no_printf_return_value>>)
 endif()
 
+if(CONFIG_UBSAN)
+  zephyr_compile_options($<$<COMPILE_LANGUAGE:C>:$<TARGET_PROPERTY:compiler,sanitizer_undefined>>)
+  zephyr_link_libraries($<TARGET_PROPERTY:linker,sanitizer_undefined>)
+  if(CONFIG_UBSAN_LIBRARY)
+    zephyr_compile_options($<$<COMPILE_LANGUAGE:C>:$<TARGET_PROPERTY:compiler,sanitizer_undefined_library>>)
+    zephyr_link_libraries($<TARGET_PROPERTY:linker,sanitizer_undefined_library>)
+  elseif(CONFIG_UBSAN_TRAP)
+    zephyr_compile_options($<$<COMPILE_LANGUAGE:C>:$<TARGET_PROPERTY:compiler,sanitizer_undefined_trap>>)
+    zephyr_link_libraries($<TARGET_PROPERTY:linker,sanitizer_undefined_trap>)
+  endif()
+endif()
+
 # @Intent: Set compiler specific flag for tentative definitions, no-common
 zephyr_compile_options($<TARGET_PROPERTY:compiler,no_common>)
 

arch/Kconfig

@@ -327,6 +327,7 @@ config PRIVILEGED_STACK_SIZE
 
 config KOBJECT_TEXT_AREA
 	int "Size of kobject text area"
+	default 1024 if UBSAN
 	default 512 if COVERAGE_GCOV
 	default 512 if NO_OPTIMIZATIONS
 	default 512 if STACK_CANARIES && RISCV

arch/arm64/core/Kconfig

@@ -126,6 +126,7 @@ config PRIVILEGED_STACK_SIZE
 	default 4096
 
 config KOBJECT_TEXT_AREA
+	default 1024 if UBSAN
 	default 512 if TEST
 
 config WAIT_AT_RESET_VECTOR

cmake/compiler/gcc/compiler_flags.cmake

@@ -197,6 +197,10 @@ if(NOT CONFIG_NO_OPTIMIZATIONS)
   set_compiler_property(PROPERTY security_fortify_run_time _FORTIFY_SOURCE=2)
 endif()
 
+check_set_compiler_property(PROPERTY sanitizer_undefined -fsanitize=undefined)
+check_set_compiler_property(PROPERTY sanitizer_undefined_trap -fsanitize-undefined-trap-on-error)
+check_set_compiler_property(PROPERTY sanitizer_undefined_library)
+
 # gcc flag for a hosted (no-freestanding) application
 check_set_compiler_property(APPEND PROPERTY hosted -fno-freestanding)
 

cmake/linker/ld/linker_flags.cmake

@@ -24,6 +24,10 @@ check_set_linker_property(TARGET linker PROPERTY orphan_error
 
 check_set_linker_property(TARGET linker PROPERTY memusage "${LINKERFLAGPREFIX},--print-memory-usage")
 
+check_set_linker_property(TARGET linker PROPERTY sanitizer_undefined -fsanitize=undefined)
+check_set_linker_property(TARGET linker PROPERTY sanitizer_undefined_trap -fsanitize-undefined-trap-on-error)
+check_set_linker_property(TARGET linker PROPERTY sanitizer_undefined_library)
+
 # -no-pie is not supported until binutils 2.37.
 # If -no-pie is passed to old binutils <= 2.36, it is parsed
 # as separate arguments -n and -o, which results in output file

subsys/debug/Kconfig

@@ -67,12 +67,35 @@ config ASAN_NOP_DLCLOSE
 
 config UBSAN
 	bool "Build with undefined behavior sanitizer"
-	depends on ARCH_POSIX
 	help
-	  Builds Zephyr with Undefined Behavior Sanitizer enabled.
-	  This is currently only supported by boards based on the posix
-	  architecture, and requires a recent-ish compiler with the
-	  ``-fsanitize=undefined`` command line option.
+	  Builds Zephyr with Undefined Behavior Sanitizer enabled.  This
+	  requires a recent-ish compiler with the ``-fsanitize=undefined``
+	  command line option.
+
+choice UBSAN_MODE
+	prompt "Undefined behavior sanitizer mode"
+	depends on UBSAN
+	default UBSAN_LIBRARY
+
+config UBSAN_LIBRARY
+	bool "Call ubsan routines"
+	depends on ARCH_POSIX || PICOLIBC
+	help
+	  Call ubsan library routines when undefined behavior is detected
+	  at runtime. This provides information about the faulting
+	  condition along with the source filename, line number, types and
+	  values involved.  This is currently only supported by boards
+	  based on the posix architecture or when building with picolibc.
+
+config UBSAN_TRAP
+	bool "Call __builtin_trap"
+	help
+	  When undefined behavior is detected, invoke __builtin_trap to
+	  cause an exception to be raised. This can be used on any target,
+	  but the lack of information makes figuring out the triggering
+	  code difficult.
+
+endchoice
 
 config MSAN
 	bool "Build with memory sanitizer"