From: Diana Craciun diana.craciun@nxp.com
commit f633a8ad636efb5d4bba1a047d4a0f1ef719aa06 upstream.
When the command line argument is present, the Spectre variant 2 mitigations are disabled.
Signed-off-by: Diana Craciun diana.craciun@nxp.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/include/asm/setup.h | 5 +++++ arch/powerpc/kernel/security.c | 21 +++++++++++++++++++++ 2 files changed, 26 insertions(+)
--- a/arch/powerpc/include/asm/setup.h +++ b/arch/powerpc/include/asm/setup.h @@ -53,6 +53,11 @@ void do_barrier_nospec_fixups_range(bool static inline void do_barrier_nospec_fixups_range(bool enable, void *start, void *end) { }; #endif
+#ifdef CONFIG_PPC_FSL_BOOK3E +void setup_spectre_v2(void); +#else +static inline void setup_spectre_v2(void) {}; +#endif void do_btb_flush_fixups(void);
#endif /* !__ASSEMBLY__ */ --- a/arch/powerpc/kernel/security.c +++ b/arch/powerpc/kernel/security.c @@ -27,6 +27,10 @@ static enum count_cache_flush_type count
bool barrier_nospec_enabled; static bool no_nospec; +static bool btb_flush_enabled; +#ifdef CONFIG_PPC_FSL_BOOK3E +static bool no_spectrev2; +#endif
static void enable_barrier_nospec(bool enable) { @@ -102,6 +106,23 @@ static __init int barrier_nospec_debugfs device_initcall(barrier_nospec_debugfs_init); #endif /* CONFIG_DEBUG_FS */
+#ifdef CONFIG_PPC_FSL_BOOK3E +static int __init handle_nospectre_v2(char *p) +{ + no_spectrev2 = true; + + return 0; +} +early_param("nospectre_v2", handle_nospectre_v2); +void setup_spectre_v2(void) +{ + if (no_spectrev2) + do_btb_flush_fixups(); + else + btb_flush_enabled = true; +} +#endif /* CONFIG_PPC_FSL_BOOK3E */ + #ifdef CONFIG_PPC_BOOK3S_64 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) {