Commit 7e945394 authored Dec 22, 2021 by Christophe Leroy Committed by Greg Kroah-Hartman Feb 01, 2022

powerpc/32: Fix boot failure with GCC latent entropy plugin



commit bba496656a73fc1d1330b49c7f82843836e9feb1 upstream.

Boot fails with GCC latent entropy plugin enabled.

This is due to early boot functions trying to access 'latent_entropy'
global data while the kernel is not relocated at its final
destination yet.

As there is no way to tell GCC to use PTRRELOC() to access it,
disable latent entropy plugin in early_32.o and feature-fixups.o and
code-patching.o

Fixes: 38addce8 ("gcc-plugins: Add latent_entropy plugin")
Cc: stable@vger.kernel.org # v4.9+
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215217
Link: https://lore.kernel.org/r/2bac55483b8daf5b1caa163a45fa5f9cdbe18be4.1640178426.git.christophe.leroy@csgroup.eu


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ff19d70b

arch/powerpc/kernel/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -13,6 +13,7 @@ CFLAGS_prom_init.o += -fPIC
		CFLAGS_btext.o += -fPIC
		endif

		CFLAGS_early_32.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
		CFLAGS_cputable.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
		CFLAGS_prom_init.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
		CFLAGS_btext.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)

arch/powerpc/lib/Makefile

+3 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,9 @@ CFLAGS_code-patching.o += -DDISABLE_BRANCH_PROFILING
		CFLAGS_feature-fixups.o += -DDISABLE_BRANCH_PROFILING
		endif

		CFLAGS_code-patching.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
		CFLAGS_feature-fixups.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)

		obj-y += alloc.o code-patching.o feature-fixups.o pmem.o

		ifndef CONFIG_KASAN