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: 38addce8b600 ("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>

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 1e64cfe22a83e09b763c156720127ca7b030861b..bf19c5514d6c2660a400e29278017cae941b92dc 100644 (file)
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -15,6 +15,7 @@ CFLAGS_prom_init.o      += -fPIC
 CFLAGS_btext.o         += -fPIC
 endif
 
+CFLAGS_setup_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)

diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 670286808928344f8484faf75a25d7f7df1a3e15..36f91308442940b83d6a3c0d7c82f187e2626f75 100644 (file)
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -10,6 +10,9 @@ ccflags-$(CONFIG_PPC64)       := $(NO_MINIMAL_TOC)
 CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
 
+CFLAGS_code-patching.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
+CFLAGS_feature-fixups.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
+
 obj-y += string.o alloc.o code-patching.o feature-fixups.o
 
 obj-$(CONFIG_PPC32)    += div64.o copy_32.o crtsavres.o strlen_32.o