[PATCH 05/11] powerpc/fsl: Add nospectre_v2 command line argument
From: Diana Craciun <hidden>
Date: 2018-12-12 14:05:57
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
When the command line argument is present, the Spectre variant 2 mitigations are disabled. Signed-off-by: Diana Craciun <redacted> --- arch/powerpc/include/asm/setup.h | 5 +++++ arch/powerpc/kernel/security.c | 21 +++++++++++++++++++++ 2 files changed, 26 insertions(+)
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index c941c8c..65676e2 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h@@ -67,6 +67,11 @@ 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 +#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__ */
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 1b395b8..4393a38 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c@@ -26,6 +26,10 @@ static enum count_cache_flush_type count_cache_flush_type = COUNT_CACHE_FLUSH_NO 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) {
@@ -101,6 +105,23 @@ static __init int barrier_nospec_debugfs_init(void) 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) {
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2.5.5