diff options
| -rw-r--r-- | arch/arm/mm/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/mm/proc-v7-bugs.c | 36 | ||||
| -rw-r--r-- | arch/arm/mm/proc-v7.S | 4 |
3 files changed, 39 insertions, 3 deletions
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index 9dbb84923e12..a0c40610210c 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -97,7 +97,7 @@ obj-$(CONFIG_CPU_MOHAWK) += proc-mohawk.o obj-$(CONFIG_CPU_FEROCEON) += proc-feroceon.o obj-$(CONFIG_CPU_V6) += proc-v6.o obj-$(CONFIG_CPU_V6K) += proc-v6.o -obj-$(CONFIG_CPU_V7) += proc-v7.o +obj-$(CONFIG_CPU_V7) += proc-v7.o proc-v7-bugs.o obj-$(CONFIG_CPU_V7M) += proc-v7m.o AFLAGS_proc-v6.o :=-Wa,-march=armv6 diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c new file mode 100644 index 000000000000..e46557db6446 --- /dev/null +++ b/arch/arm/mm/proc-v7-bugs.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/smp.h> + +static __maybe_unused void cpu_v7_check_auxcr_set(bool *warned, + u32 mask, const char *msg) +{ + u32 aux_cr; + + asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (aux_cr)); + + if ((aux_cr & mask) != mask) { + if (!*warned) + pr_err("CPU%u: %s", smp_processor_id(), msg); + *warned = true; + } +} + +static DEFINE_PER_CPU(bool, spectre_warned); + +static void check_spectre_auxcr(bool *warned, u32 bit) +{ + if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR) && + cpu_v7_check_auxcr_set(warned, bit, + "Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable\n"); +} + +void cpu_v7_ca8_ibe(void) +{ + check_spectre_auxcr(this_cpu_ptr(&spectre_warned), BIT(6)); +} + +void cpu_v7_ca15_ibe(void) +{ + check_spectre_auxcr(this_cpu_ptr(&spectre_warned), BIT(0)); +} diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index a2d433d59848..fa9214036fb3 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -569,7 +569,7 @@ __v7_setup_stack: 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 + define_processor_functions ca8, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca8_ibe @ Cortex-A9 - needs more registers preserved across suspend/resume @ and bpiall switch_mm for hardening @@ -602,7 +602,7 @@ __v7_setup_stack: 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 + define_processor_functions ca15, dabort=v7_early_abort, pabort=v7_pabort, suspend=1, bugs=cpu_v7_ca15_ibe #ifdef CONFIG_CPU_PJ4B define_processor_functions pj4b, dabort=v7_early_abort, pabort=v7_pabort, suspend=1 #endif |