diff options
| author | Diana Craciun <diana.craciun@nxp.com> | 2019-04-11 21:46:18 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-17 08:36:42 +0200 |
| commit | d91460f2d0efc0fe6a197fc739e30edab6070456 (patch) | |
| tree | f8b159803a00736195ee0541c23a523df01188b4 /arch/powerpc/include | |
| parent | ae361096d6857727275631d1d64bcd8fec2d8f25 (diff) | |
powerpc/fsl: Add infrastructure to fixup branch predictor flush
commit 76a5eaa38b15dda92cd6964248c39b5a6f3a4e9d upstream.
In order to protect against speculation attacks (Spectre
variant 2) on NXP PowerPC platforms, the branch predictor
should be flushed when the privillege level is changed.
This patch is adding the infrastructure to fixup at runtime
the code sections that are performing the branch predictor flush
depending on a boot arg parameter which is added later in a
separate patch.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/feature-fixups.h | 12 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/setup.h | 2 |
2 files changed, 14 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/feature-fixups.h b/arch/powerpc/include/asm/feature-fixups.h index afd3efd38938..175128e19025 100644 --- a/arch/powerpc/include/asm/feature-fixups.h +++ b/arch/powerpc/include/asm/feature-fixups.h @@ -221,6 +221,17 @@ void setup_feature_keys(void); FTR_ENTRY_OFFSET 953b-954b; \ .popsection; +#define START_BTB_FLUSH_SECTION \ +955: \ + +#define END_BTB_FLUSH_SECTION \ +956: \ + .pushsection __btb_flush_fixup,"a"; \ + .align 2; \ +957: \ + FTR_ENTRY_OFFSET 955b-957b; \ + FTR_ENTRY_OFFSET 956b-957b; \ + .popsection; #ifndef __ASSEMBLY__ @@ -229,6 +240,7 @@ extern long __start___stf_entry_barrier_fixup, __stop___stf_entry_barrier_fixup; extern long __start___stf_exit_barrier_fixup, __stop___stf_exit_barrier_fixup; extern long __start___rfi_flush_fixup, __stop___rfi_flush_fixup; extern long __start___barrier_nospec_fixup, __stop___barrier_nospec_fixup; +extern long __start__btb_flush_fixup, __stop__btb_flush_fixup; #endif diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h index d3e9da62d029..23ee67e279ae 100644 --- a/arch/powerpc/include/asm/setup.h +++ b/arch/powerpc/include/asm/setup.h @@ -65,6 +65,8 @@ void do_barrier_nospec_fixups_range(bool enable, void *start, void *end); static inline void do_barrier_nospec_fixups_range(bool enable, void *start, void *end) { }; #endif +void do_btb_flush_fixups(void); + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_POWERPC_SETUP_H */ |