[PATCH stable v4.9 13/35] powerpc/64: Add CONFIG_PPC_BARRIER_NOSPEC

Michael Ellerman
2019-04-11T11:46:59Z

commit 179ab1cbf883575c3a585bcfc0f2160f1d22a149 upstream.

Add a config symbol to encode which platforms support the
barrier_nospec speculation barrier. Currently this is just Book3S 64
but we will add Book3E in a future patch.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/Kconfig | 7 ++++++-
arch/powerpc/include/asm/barrier.h | 6 +++---
arch/powerpc/include/asm/setup.h | 2 +-
arch/powerpc/kernel/Makefile | 3 ++-
arch/powerpc/kernel/module.c | 4 +++-
arch/powerpc/kernel/vmlinux.lds.S | 4 +++-
arch/powerpc/lib/feature-fixups.c | 6 ++++--
7 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 0a6bb48854e3..a238698178fc 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -128,7 +128,7 @@ config PPC
select ARCH_HAS_GCOV_PROFILE_ALL
select GENERIC_SMP_IDLE_THREAD
select GENERIC_CMOS_UPDATE
- select GENERIC_CPU_VULNERABILITIES if PPC_BOOK3S_64
+ select GENERIC_CPU_VULNERABILITIES if PPC_BARRIER_NOSPEC
select GENERIC_TIME_VSYSCALL_OLD
select GENERIC_CLOCKEVENTS
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
@@ -164,6 +164,11 @@ config PPC
select HAVE_ARCH_HARDENED_USERCOPY
select HAVE_KERNEL_GZIP

+config PPC_BARRIER_NOSPEC
+ bool
+ default y
+ depends on PPC_BOOK3S_64
+
config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN

diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index a8131162104f..465a64316897 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -77,7 +77,7 @@ do { \

#define smp_mb__before_spinlock() smp_mb()

-#ifdef CONFIG_PPC_BOOK3S_64
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
/*
* Prevent execution of subsequent instructions until preceding branches have
* been fully resolved and are no longer executing speculatively.
@@ -87,10 +87,10 @@ do { \
// This also acts as a compiler barrier due to the memory clobber.
#define barrier_nospec() asm (stringify_in_c(barrier_nospec_asm) ::: "memory")

-#else /* !CONFIG_PPC_BOOK3S_64 */
+#else /* !CONFIG_PPC_BARRIER_NOSPEC */
#define barrier_nospec_asm
#define barrier_nospec()
-#endif
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */

#include <asm-generic/barrier.h>

diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 84ae150ce6a6..38525bd2ed65 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -55,7 +55,7 @@ void setup_barrier_nospec(void);
void do_barrier_nospec_fixups(bool enable);
extern bool barrier_nospec_enabled;

-#ifdef CONFIG_PPC_BOOK3S_64
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
void do_barrier_nospec_fixups_range(bool enable, void *start, void *end);
#else
static inline void do_barrier_nospec_fixups_range(bool enable, void *start, void *end) { };
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 13885786282b..d80fbf0884ff 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -44,9 +44,10 @@ obj-$(CONFIG_PPC64) += setup_64.o sys_ppc32.o \
obj-$(CONFIG_VDSO32) += vdso32/
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_ppc970.o cpu_setup_pa6t.o
-obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o security.o
+obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o
obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o
obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o
+obj-$(CONFIG_PPC_BARRIER_NOSPEC) += security.o
obj-$(CONFIG_PPC64) += vdso64/
obj-$(CONFIG_ALTIVEC) += vecemu.o
obj-$(CONFIG_PPC_970_NAP) += idle_power4.o
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index d30f0626dcd0..3b1c3bb91025 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -72,13 +72,15 @@ int module_finalize(const Elf_Ehdr *hdr,
do_feature_fixups(powerpc_firmware_features,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
+#endif /* CONFIG_PPC64 */

+#ifdef CONFIG_PPC_BARRIER_NOSPEC
sect = find_section(hdr, sechdrs, "__spec_barrier_fixup");
if (sect != NULL)
do_barrier_nospec_fixups_range(barrier_nospec_enabled,
(void *)sect->sh_addr,
(void *)sect->sh_addr + sect->sh_size);
-#endif
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */

sect = find_section(hdr, sechdrs, "__lwsync_fixup");
if (sect != NULL)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 61def0be6914..5c6cf58943b9 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -153,14 +153,16 @@ SECTIONS
*(__rfi_flush_fixup)
__stop___rfi_flush_fixup = .;
}
+#endif /* CONFIG_PPC64 */

+#ifdef CONFIG_PPC_BARRIER_NOSPEC
. = ALIGN(8);
__spec_barrier_fixup : AT(ADDR(__spec_barrier_fixup) - LOAD_OFFSET) {
__start___barrier_nospec_fixup = .;
*(__barrier_nospec_fixup)
__stop___barrier_nospec_fixup = .;
}
-#endif
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */

EXCEPTION_TABLE(0)

diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index a1222c441df5..5df57f7bae0a 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -304,6 +304,9 @@ void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_
printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
}

+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
void do_barrier_nospec_fixups(bool enable)
{
void *start, *end;
@@ -313,8 +316,7 @@ void do_barrier_nospec_fixups(bool enable)

do_barrier_nospec_fixups_range(enable, start, end);
}
-
-#endif /* CONFIG_PPC_BOOK3S_64 */
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */

void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
{
--
2.20.1