latent_entropy: raise CONFIG_FRAME_WARN by default

When building with the latent_entropy plugin, set the default
CONFIG_FRAME_WARN to 2048, since some __init functions have many basic
blocks that, when instrumented by the latent_entropy plugin, grow beyond
1024 byte stack size on 32-bit builds.

Link: http://lkml.kernel.org/r/20161018211216.GA39687@beast
Signed-off-by: Kees Cook <[email protected]>
Reported-by: kbuild test robot <[email protected]>
Cc: Emese Revfy <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Michal Marek <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Nikolay Aleksandrov <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 33bc56cf60d71fc81f5f5981100406e1c7a91b10..b01e547d4d04475e19590aad8f16c403076f7eb6 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -198,6 +198,7 @@ config FRAME_WARN
        int "Warn for stack frames larger than (needs gcc 4.4)"
        range 0 8192
        default 0 if KASAN
+       default 2048 if GCC_PLUGIN_LATENT_ENTROPY
        default 1024 if !64BIT
        default 2048 if 64BIT
        help