From 4c2280b10e50c7964bd72c893994b9ad92fe01d7 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 30 Sep 2018 17:22:52 -0400 Subject: ARM: spectre-v2: harden branch predictor on context switches Commit 06c23f5ffe7ad45b908d0fff604dae08a7e334b9 upstream. Required manual merge of arch/arm/mm/proc-v7.S. Harden the branch predictor against Spectre v2 attacks on context switches for ARMv7 and later CPUs. We do this by: Cortex A9, A12, A17, A73, A75: invalidating the BTB. Cortex A15, Brahma B15: invalidating the instruction cache. Cortex A57 and Cortex A72 are not addressed in this patch. Cortex R7 and Cortex R8 are also not addressed as we do not enforce memory protection on these cores. Signed-off-by: Russell King Boot-tested-by: Tony Lindgren Reviewed-by: Tony Lindgren Acked-by: Marc Zyngier Signed-off-by: David A. Long --- arch/arm/mm/proc-v7.S | 125 ++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 96 insertions(+), 29 deletions(-) (limited to 'arch/arm/mm/proc-v7.S') diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index 8e1ea433c3f1..c2950317c7c2 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -87,6 +87,17 @@ ENTRY(cpu_v7_dcache_clean_area) ret lr ENDPROC(cpu_v7_dcache_clean_area) +ENTRY(cpu_v7_iciallu_switch_mm) + mov r3, #0 + mcr p15, 0, r3, c7, c5, 0 @ ICIALLU + b cpu_v7_switch_mm +ENDPROC(cpu_v7_iciallu_switch_mm) +ENTRY(cpu_v7_bpiall_switch_mm) + mov r3, #0 + mcr p15, 0, r3, c7, c5, 6 @ flush BTAC/BTB + b cpu_v7_switch_mm +ENDPROC(cpu_v7_bpiall_switch_mm) + string cpu_v7_name, "ARMv7 Processor" .align @@ -152,31 +163,6 @@ ENTRY(cpu_v7_do_resume) ENDPROC(cpu_v7_do_resume) #endif -/* - * Cortex-A8 - */ - globl_equ cpu_ca8_proc_init, cpu_v7_proc_init - globl_equ cpu_ca8_proc_fin, cpu_v7_proc_fin - globl_equ cpu_ca8_reset, cpu_v7_reset - globl_equ cpu_ca8_do_idle, cpu_v7_do_idle - globl_equ cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area - globl_equ cpu_ca8_set_pte_ext, cpu_v7_set_pte_ext - globl_equ cpu_ca8_suspend_size, cpu_v7_suspend_size -#ifdef CONFIG_ARM_CPU_SUSPEND - globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend - globl_equ cpu_ca8_do_resume, cpu_v7_do_resume -#endif - -/* - * Cortex-A9 processor functions - */ - globl_equ cpu_ca9mp_proc_init, cpu_v7_proc_init - globl_equ cpu_ca9mp_proc_fin, cpu_v7_proc_fin - globl_equ cpu_ca9mp_reset, cpu_v7_reset - globl_equ cpu_ca9mp_do_idle, cpu_v7_do_idle - globl_equ cpu_ca9mp_dcache_clean_area, cpu_v7_dcache_clean_area - globl_equ cpu_ca9mp_switch_mm, cpu_v7_switch_mm - globl_equ cpu_ca9mp_set_pte_ext, cpu_v7_set_pte_ext .globl cpu_ca9mp_suspend_size .equ cpu_ca9mp_suspend_size, cpu_v7_suspend_size + 4 * 2 #ifdef CONFIG_ARM_CPU_SUSPEND @@ -490,10 +476,75 @@ __v7_setup_stack: @ define struct processor (see and proc-macros.S) define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 + +#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR + @ generic v7 bpiall on context switch + globl_equ cpu_v7_bpiall_proc_init, cpu_v7_proc_init + globl_equ cpu_v7_bpiall_proc_fin, cpu_v7_proc_fin + globl_equ cpu_v7_bpiall_reset, cpu_v7_reset + globl_equ cpu_v7_bpiall_do_idle, cpu_v7_do_idle + globl_equ cpu_v7_bpiall_dcache_clean_area, cpu_v7_dcache_clean_area + globl_equ cpu_v7_bpiall_set_pte_ext, cpu_v7_set_pte_ext + globl_equ cpu_v7_bpiall_suspend_size, cpu_v7_suspend_size +#ifdef CONFIG_ARM_CPU_SUSPEND + globl_equ cpu_v7_bpiall_do_suspend, cpu_v7_do_suspend + globl_equ cpu_v7_bpiall_do_resume, cpu_v7_do_resume +#endif + define_processor_functions v7_bpiall, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 + +#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_bpiall_processor_functions +#else +#define HARDENED_BPIALL_PROCESSOR_FUNCTIONS v7_processor_functions +#endif + #ifndef CONFIG_ARM_LPAE + @ Cortex-A8 - always needs bpiall switch_mm implementation + globl_equ cpu_ca8_proc_init, cpu_v7_proc_init + globl_equ cpu_ca8_proc_fin, cpu_v7_proc_fin + globl_equ cpu_ca8_reset, cpu_v7_reset + globl_equ cpu_ca8_do_idle, cpu_v7_do_idle + globl_equ cpu_ca8_dcache_clean_area, cpu_v7_dcache_clean_area + globl_equ cpu_ca8_set_pte_ext, cpu_v7_set_pte_ext + globl_equ cpu_ca8_switch_mm, cpu_v7_bpiall_switch_mm + globl_equ cpu_ca8_suspend_size, cpu_v7_suspend_size +#ifdef CONFIG_ARM_CPU_SUSPEND + globl_equ cpu_ca8_do_suspend, cpu_v7_do_suspend + globl_equ cpu_ca8_do_resume, cpu_v7_do_resume +#endif define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 + + @ Cortex-A9 - needs more registers preserved across suspend/resume + @ and bpiall switch_mm for hardening + globl_equ cpu_ca9mp_proc_init, cpu_v7_proc_init + globl_equ cpu_ca9mp_proc_fin, cpu_v7_proc_fin + globl_equ cpu_ca9mp_reset, cpu_v7_reset + globl_equ cpu_ca9mp_do_idle, cpu_v7_do_idle + globl_equ cpu_ca9mp_dcache_clean_area, cpu_v7_dcache_clean_area +#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR + globl_equ cpu_ca9mp_switch_mm, cpu_v7_bpiall_switch_mm +#else + globl_equ cpu_ca9mp_switch_mm, cpu_v7_switch_mm +#endif + globl_equ cpu_ca9mp_set_pte_ext, cpu_v7_set_pte_ext define_processor_functions ca9mp, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 #endif + + @ Cortex-A15 - needs iciallu switch_mm for hardening + globl_equ cpu_ca15_proc_init, cpu_v7_proc_init + globl_equ cpu_ca15_proc_fin, cpu_v7_proc_fin + globl_equ cpu_ca15_reset, cpu_v7_reset + globl_equ cpu_ca15_do_idle, cpu_v7_do_idle + globl_equ cpu_ca15_dcache_clean_area, cpu_v7_dcache_clean_area +#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR + globl_equ cpu_ca15_switch_mm, cpu_v7_iciallu_switch_mm +#else + globl_equ cpu_ca15_switch_mm, cpu_v7_switch_mm +#endif + globl_equ cpu_ca15_set_pte_ext, cpu_v7_set_pte_ext + globl_equ cpu_ca15_suspend_size, cpu_v7_suspend_size + globl_equ cpu_ca15_do_suspend, cpu_v7_do_suspend + globl_equ cpu_ca15_do_resume, cpu_v7_do_resume + define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 #ifdef CONFIG_CPU_PJ4B define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 #endif @@ -600,7 +651,7 @@ __v7_ca7mp_proc_info: __v7_ca12mp_proc_info: .long 0x410fc0d0 .long 0xff0ffff0 - __v7_proc __v7_ca12mp_proc_info, __v7_ca12mp_setup + __v7_proc __v7_ca12mp_proc_info, __v7_ca12mp_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS .size __v7_ca12mp_proc_info, . - __v7_ca12mp_proc_info /* @@ -610,7 +661,7 @@ __v7_ca12mp_proc_info: __v7_ca15mp_proc_info: .long 0x410fc0f0 .long 0xff0ffff0 - __v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup + __v7_proc __v7_ca15mp_proc_info, __v7_ca15mp_setup, proc_fns = ca15_processor_functions .size __v7_ca15mp_proc_info, . - __v7_ca15mp_proc_info /* @@ -620,7 +671,7 @@ __v7_ca15mp_proc_info: __v7_b15mp_proc_info: .long 0x420f00f0 .long 0xff0ffff0 - __v7_proc __v7_b15mp_proc_info, __v7_b15mp_setup + __v7_proc __v7_b15mp_proc_info, __v7_b15mp_setup, proc_fns = ca15_processor_functions .size __v7_b15mp_proc_info, . - __v7_b15mp_proc_info /* @@ -630,9 +681,25 @@ __v7_b15mp_proc_info: __v7_ca17mp_proc_info: .long 0x410fc0e0 .long 0xff0ffff0 - __v7_proc __v7_ca17mp_proc_info, __v7_ca17mp_setup + __v7_proc __v7_ca17mp_proc_info, __v7_ca17mp_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS .size __v7_ca17mp_proc_info, . - __v7_ca17mp_proc_info + /* ARM Ltd. Cortex A73 processor */ + .type __v7_ca73_proc_info, #object +__v7_ca73_proc_info: + .long 0x410fd090 + .long 0xff0ffff0 + __v7_proc __v7_ca73_proc_info, __v7_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS + .size __v7_ca73_proc_info, . - __v7_ca73_proc_info + + /* ARM Ltd. Cortex A75 processor */ + .type __v7_ca75_proc_info, #object +__v7_ca75_proc_info: + .long 0x410fd0a0 + .long 0xff0ffff0 + __v7_proc __v7_ca75_proc_info, __v7_setup, proc_fns = HARDENED_BPIALL_PROCESSOR_FUNCTIONS + .size __v7_ca75_proc_info, . - __v7_ca75_proc_info + /* * Qualcomm Inc. Krait processors. */ -- cgit v1.2.3