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authorKees Cook <keescook@chromium.org>2020-04-06 20:12:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-07 10:43:44 -0700
commit0887a7ebc97770c7870abf3075a2e8cd502a7f52 (patch)
tree252f41ece044990e2a10a1c58e5b9575a498deec /lib/Makefile
parent7baf219982281034f8c3a806869873bf098fb611 (diff)
ubsan: add trap instrumentation option
Patch series "ubsan: Split out bounds checker", v5. This splits out the bounds checker so it can be individually used. This is enabled in Android and hopefully for syzbot. Includes LKDTM tests for behavioral corner-cases (beyond just the bounds checker), and adjusts ubsan and kasan slightly for correct panic handling. This patch (of 6): The Undefined Behavior Sanitizer can operate in two modes: warning reporting mode via lib/ubsan.c handler calls, or trap mode, which uses __builtin_trap() as the handler. Using lib/ubsan.c means the kernel image is about 5% larger (due to all the debugging text and reporting structures to capture details about the warning conditions). Using the trap mode, the image size changes are much smaller, though at the loss of the "warning only" mode. In order to give greater flexibility to system builders that want minimal changes to image size and are prepared to deal with kernel code being aborted and potentially destabilizing the system, this introduces CONFIG_UBSAN_TRAP. The resulting image sizes comparison: text data bss dec hex filename 19533663 6183037 18554956 44271656 2a38828 vmlinux.stock 19991849 7618513 18874448 46484810 2c54d4a vmlinux.ubsan 19712181 6284181 18366540 44362902 2a4ec96 vmlinux.ubsan-trap CONFIG_UBSAN=y: image +4.8% (text +2.3%, data +18.9%) CONFIG_UBSAN_TRAP=y: image +0.2% (text +0.9%, data +1.6%) Additionally adjusts the CONFIG_UBSAN Kconfig help for clarity and removes the mention of non-existing boot param "ubsan_handle". Suggested-by: Elena Petrova <lenaptr@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Link: http://lkml.kernel.org/r/20200227193516.32566-2-keescook@chromium.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/Makefile')
-rw-r--r--lib/Makefile2
1 files changed, 2 insertions, 0 deletions
diff --git a/lib/Makefile b/lib/Makefile
index 3fc06399295d..685aee60de1d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -286,7 +286,9 @@ quiet_cmd_build_OID_registry = GEN $@
clean-files += oid_registry_data.c
obj-$(CONFIG_UCS2_STRING) += ucs2_string.o
+ifneq ($(CONFIG_UBSAN_TRAP),y)
obj-$(CONFIG_UBSAN) += ubsan.o
+endif
UBSAN_SANITIZE_ubsan.o := n
KASAN_SANITIZE_ubsan.o := n