powerpc/kasan: Fix stack overflow by increasing THREAD_SHIFT

[ Upstream commit edbadaf0671072298e506074128b64e003c5812c ]

When CONFIG_KASAN is selected, the stack usage is increased.

In the same way as x86 and arm64 architectures, increase
THREAD_SHIFT when CONFIG_KASAN is selected.

Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support")
Reported-by: <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=207129
Link: https://lore.kernel.org/r/2c50f3b1c9bbaa4217c9a98f3044bd2a36c46a4f.1586361277.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 62aca9efbbbed0a5f95a911225d9a22f9b9525fe..310957b988e31dbf790aff5b406cb9e0a89bf66d 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -773,6 +773,7 @@ config THREAD_SHIFT
        range 13 15
        default "15" if PPC_256K_PAGES
        default "14" if PPC64
+       default "14" if KASAN
        default "13"
        help
          Used to define the stack size. The default is almost always what you