| Message ID | 20191105235608.107702-15-samitolvanen@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v5,01/14] arm64: mm: avoid x18 in idmap_kpti_install_ng_mappings | expand |
On Tue, Nov 05, 2019 at 03:56:08PM -0800, Sami Tolvanen wrote: > This change implements shadow stack switching, initial SCS set-up, > and interrupt shadow stacks for arm64. Each CPU also has an overflow stack, and two SDEI stacks, which should presumably be given their own SCS. SDEI is effectively a software-NMI, so it should almost certainly have the same treatement as IRQ. > +static __always_inline void scs_save(struct task_struct *tsk) > +{ > + void *s; > + > + asm volatile("mov %0, x18" : "=r" (s)); > + task_set_scs(tsk, s); > +} An alternative would be to follow <asm/stack_pointer.h>, and have: register unsigned long *current_scs_pointer asm ("x18"); static __always_inline void scs_save(struct task_struct *tsk) { task_set_scs(tsk, current_scs_pointer); } ... which would avoid the need for a temporary register where this is used. However, given we only use this in cpu_die(), having this as-is should be fine. Maybe the asm volatile is preferable if we use this elsewhere, so that we know we have a consistent snapshot that the compiler can't reload, etc. [...] > @@ -409,6 +428,10 @@ alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0 > */ > .macro irq_stack_exit > mov sp, x19 > +#ifdef CONFIG_SHADOW_CALL_STACK > + /* x20 is also preserved */ > + mov x18, x20 > +#endif > .endm Can we please fold this comment into the one above, and have: /* * The callee-saved regs (x19-x29) should be preserved between * irq_stack_entry and irq_stack_exit. */ .macro irq_stack_exit mov sp, x19 #ifdef CONFIG_SHADOW_CALL_STACK mov x18, x20 #endif .endm Thanks, Mark.
On Fri, Nov 15, 2019 at 7:20 AM Mark Rutland <mark.rutland@arm.com> wrote: > > On Tue, Nov 05, 2019 at 03:56:08PM -0800, Sami Tolvanen wrote: > > This change implements shadow stack switching, initial SCS set-up, > > and interrupt shadow stacks for arm64. > > Each CPU also has an overflow stack, and two SDEI stacks, which should > presumably be given their own SCS. SDEI is effectively a software-NMI, > so it should almost certainly have the same treatement as IRQ. Makes sense. I'll take a look at adding shadow stacks for the SDEI handler. > Can we please fold this comment into the one above, and have: > > /* > * The callee-saved regs (x19-x29) should be preserved between > * irq_stack_entry and irq_stack_exit. > */ > .macro irq_stack_exit > mov sp, x19 > #ifdef CONFIG_SHADOW_CALL_STACK > mov x18, x20 > #endif > .endm Sure, I'll change this in the next version. Sami
On Fri, Nov 15, 2019 at 12:19:20PM -0800, Sami Tolvanen wrote: > On Fri, Nov 15, 2019 at 7:20 AM Mark Rutland <mark.rutland@arm.com> wrote: > > > > On Tue, Nov 05, 2019 at 03:56:08PM -0800, Sami Tolvanen wrote: > > > This change implements shadow stack switching, initial SCS set-up, > > > and interrupt shadow stacks for arm64. > > > > Each CPU also has an overflow stack, and two SDEI stacks, which should > > presumably be given their own SCS. SDEI is effectively a software-NMI, > > so it should almost certainly have the same treatement as IRQ. > > Makes sense. I'll take a look at adding shadow stacks for the SDEI handler. Mark, I wrote a preliminary patch for adding SDEI shadow stacks, but turns out I don't really have a way to test the SDEI code. Does the approach below look sane to you? Sami --- arch/arm64/include/asm/scs.h | 2 + arch/arm64/include/asm/stacktrace.h | 4 -- arch/arm64/kernel/entry.S | 14 +++- arch/arm64/kernel/scs.c | 106 +++++++++++++++++++++++----- arch/arm64/kernel/sdei.c | 7 ++ 5 files changed, 112 insertions(+), 21 deletions(-) diff --git a/arch/arm64/include/asm/scs.h b/arch/arm64/include/asm/scs.h index c50d2b0c6c5f..8e327e14bc15 100644 --- a/arch/arm64/include/asm/scs.h +++ b/arch/arm64/include/asm/scs.h @@ -9,6 +9,7 @@ #ifdef CONFIG_SHADOW_CALL_STACK extern void scs_init_irq(void); +extern int scs_init_sdei(void); static __always_inline void scs_save(struct task_struct *tsk) { @@ -27,6 +28,7 @@ static inline void scs_overflow_check(struct task_struct *tsk) #else /* CONFIG_SHADOW_CALL_STACK */ static inline void scs_init_irq(void) {} +static inline int scs_init_sdei(void) { return 0; } static inline void scs_save(struct task_struct *tsk) {} static inline void scs_overflow_check(struct task_struct *tsk) {} diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index b6cf32fb4efe..4d9b1f48dc39 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -68,10 +68,6 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk); DECLARE_PER_CPU(unsigned long *, irq_stack_ptr); -#ifdef CONFIG_SHADOW_CALL_STACK -DECLARE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr); -#endif - static inline bool on_irq_stack(unsigned long sp, struct stack_info *info) { diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 5a02b61fc3e6..ac9dfb3da440 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -1309,13 +1309,16 @@ ENTRY(__sdei_asm_handler) mov x19, x1 +#if defined(CONFIG_VMAP_STACK) || defined(CONFIG_SHADOW_CALL_STACK) + ldrb w4, [x19, #SDEI_EVENT_PRIORITY] +#endif + #ifdef CONFIG_VMAP_STACK /* * entry.S may have been using sp as a scratch register, find whether * this is a normal or critical event and switch to the appropriate * stack for this CPU. */ - ldrb w4, [x19, #SDEI_EVENT_PRIORITY] cbnz w4, 1f ldr_this_cpu dst=x5, sym=sdei_stack_normal_ptr, tmp=x6 b 2f @@ -1325,6 +1328,15 @@ ENTRY(__sdei_asm_handler) mov sp, x5 #endif +#ifdef CONFIG_SHADOW_CALL_STACK + /* Use a separate shadow call stack for normal and critical events */ + cbnz w4, 3f + ldr_this_cpu dst=x18, sym=sdei_shadow_call_stack_normal_ptr, tmp=x6 + b 4f +3: ldr_this_cpu dst=x18, sym=sdei_shadow_call_stack_critical_ptr, tmp=x6 +4: +#endif + /* * We may have interrupted userspace, or a guest, or exit-from or * return-to either of these. We can't trust sp_el0, restore it. diff --git a/arch/arm64/kernel/scs.c b/arch/arm64/kernel/scs.c index 9a1305a6eb5b..dddb7c56518b 100644 --- a/arch/arm64/kernel/scs.c +++ b/arch/arm64/kernel/scs.c @@ -10,31 +10,105 @@ #include <asm/pgtable.h> #include <asm/scs.h> -DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr); +#define DECLARE_SCS(name) \ + DECLARE_PER_CPU(unsigned long *, name ## _ptr); \ + DECLARE_PER_CPU(unsigned long [SCS_SIZE/sizeof(long)], name) -#ifndef CONFIG_SHADOW_CALL_STACK_VMAP -DEFINE_PER_CPU(unsigned long [SCS_SIZE/sizeof(long)], irq_shadow_call_stack) - __aligned(SCS_SIZE); +#ifdef CONFIG_SHADOW_CALL_STACK_VMAP +#define DEFINE_SCS(name) \ + DEFINE_PER_CPU(unsigned long *, name ## _ptr) +#else +/* Allocate a static per-CPU shadow stack */ +#define DEFINE_SCS(name) \ + DEFINE_PER_CPU(unsigned long *, name ## _ptr); \ + DEFINE_PER_CPU(unsigned long [SCS_SIZE/sizeof(long)], name) \ + __aligned(SCS_SIZE) +#endif /* CONFIG_SHADOW_CALL_STACK_VMAP */ + +DECLARE_SCS(irq_shadow_call_stack); +DECLARE_SCS(sdei_shadow_call_stack_normal); +DECLARE_SCS(sdei_shadow_call_stack_critical); + +DEFINE_SCS(irq_shadow_call_stack); +#ifdef CONFIG_ARM_SDE_INTERFACE +DEFINE_SCS(sdei_shadow_call_stack_normal); +DEFINE_SCS(sdei_shadow_call_stack_critical); #endif +static int scs_alloc_percpu(unsigned long * __percpu *ptr, int cpu) +{ + unsigned long *p; + + p = __vmalloc_node_range(PAGE_SIZE, SCS_SIZE, + VMALLOC_START, VMALLOC_END, + GFP_SCS, PAGE_KERNEL, + 0, cpu_to_node(cpu), + __builtin_return_address(0)); + + if (!p) + return -ENOMEM; + per_cpu(*ptr, cpu) = p; + + return 0; +} + +static void scs_free_percpu(unsigned long * __percpu *ptr, int cpu) +{ + unsigned long *p = per_cpu(*ptr, cpu); + + if (p) { + per_cpu(*ptr, cpu) = NULL; + vfree(p); + } +} + +static void scs_free_sdei(void) +{ + int cpu; + + for_each_possible_cpu(cpu) { + scs_free_percpu(&sdei_shadow_call_stack_normal_ptr, cpu); + scs_free_percpu(&sdei_shadow_call_stack_critical_ptr, cpu); + } +} + void scs_init_irq(void) { int cpu; for_each_possible_cpu(cpu) { -#ifdef CONFIG_SHADOW_CALL_STACK_VMAP - unsigned long *p; + if (IS_ENABLED(CONFIG_SHADOW_CALL_STACK_VMAP)) + WARN_ON(scs_alloc_percpu(&irq_shadow_call_stack_ptr, + cpu)); + else + per_cpu(irq_shadow_call_stack_ptr, cpu) = + per_cpu(irq_shadow_call_stack, cpu); + } +} - p = __vmalloc_node_range(SCS_SIZE, SCS_SIZE, - VMALLOC_START, VMALLOC_END, - GFP_SCS, PAGE_KERNEL, - 0, cpu_to_node(cpu), - __builtin_return_address(0)); +int scs_init_sdei(void) +{ + int cpu; - per_cpu(irq_shadow_call_stack_ptr, cpu) = p; -#else - per_cpu(irq_shadow_call_stack_ptr, cpu) = - per_cpu(irq_shadow_call_stack, cpu); -#endif /* CONFIG_SHADOW_CALL_STACK_VMAP */ + if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE)) + return 0; + + for_each_possible_cpu(cpu) { + if (IS_ENABLED(CONFIG_SHADOW_CALL_STACK_VMAP)) { + if (scs_alloc_percpu( + &sdei_shadow_call_stack_normal_ptr, cpu) || + scs_alloc_percpu( + &sdei_shadow_call_stack_critical_ptr, cpu)) { + scs_free_sdei(); + return -ENOMEM; + } + } else { + per_cpu(sdei_shadow_call_stack_normal_ptr, cpu) = + per_cpu(sdei_shadow_call_stack_normal, cpu); + per_cpu(sdei_shadow_call_stack_critical_ptr, cpu) = + per_cpu(sdei_shadow_call_stack_critical, cpu); + } } + + return 0; } diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c index ea94cf8f9dc6..3e85017a9c8b 100644 --- a/arch/arm64/kernel/sdei.c +++ b/arch/arm64/kernel/sdei.c @@ -12,6 +12,7 @@ #include <asm/kprobes.h> #include <asm/mmu.h> #include <asm/ptrace.h> +#include <asm/scs.h> #include <asm/sections.h> #include <asm/stacktrace.h> #include <asm/sysreg.h> @@ -161,6 +162,12 @@ unsigned long sdei_arch_get_entry_point(int conduit) return 0; } + if (scs_init_sdei()) { + if (IS_ENABLED(CONFIG_VMAP_STACK)) + free_sdei_stacks(); + return 0; + } + sdei_exit_mode = (conduit == CONDUIT_HVC) ? SDEI_EXIT_HVC : SDEI_EXIT_SMC; #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 8cda176dad9a..76e32d01d759 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -66,6 +66,7 @@ config ARM64 select ARCH_USE_QUEUED_RWLOCKS select ARCH_USE_QUEUED_SPINLOCKS select ARCH_SUPPORTS_MEMORY_FAILURE + select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG select ARCH_SUPPORTS_NUMA_BALANCING @@ -948,6 +949,10 @@ config ARCH_HAS_CACHE_LINE_SIZE config ARCH_ENABLE_SPLIT_PMD_PTLOCK def_bool y if PGTABLE_LEVELS > 2 +# Supported by clang >= 7.0 +config CC_HAVE_SHADOW_CALL_STACK + def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) + config SECCOMP bool "Enable seccomp to safely compute untrusted bytecode" ---help--- diff --git a/arch/arm64/include/asm/scs.h b/arch/arm64/include/asm/scs.h new file mode 100644 index 000000000000..c50d2b0c6c5f --- /dev/null +++ b/arch/arm64/include/asm/scs.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_SCS_H +#define _ASM_SCS_H + +#ifndef __ASSEMBLY__ + +#include <linux/scs.h> + +#ifdef CONFIG_SHADOW_CALL_STACK + +extern void scs_init_irq(void); + +static __always_inline void scs_save(struct task_struct *tsk) +{ + void *s; + + asm volatile("mov %0, x18" : "=r" (s)); + task_set_scs(tsk, s); +} + +static inline void scs_overflow_check(struct task_struct *tsk) +{ + if (unlikely(scs_corrupted(tsk))) + panic("corrupted shadow stack detected inside scheduler\n"); +} + +#else /* CONFIG_SHADOW_CALL_STACK */ + +static inline void scs_init_irq(void) {} +static inline void scs_save(struct task_struct *tsk) {} +static inline void scs_overflow_check(struct task_struct *tsk) {} + +#endif /* CONFIG_SHADOW_CALL_STACK */ + +#endif /* __ASSEMBLY __ */ + +#endif /* _ASM_SCS_H */ diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index 4d9b1f48dc39..b6cf32fb4efe 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -68,6 +68,10 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk); DECLARE_PER_CPU(unsigned long *, irq_stack_ptr); +#ifdef CONFIG_SHADOW_CALL_STACK +DECLARE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr); +#endif + static inline bool on_irq_stack(unsigned long sp, struct stack_info *info) { diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index f0cec4160136..8c73764b9ed2 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -41,6 +41,9 @@ struct thread_info { #endif } preempt; }; +#ifdef CONFIG_SHADOW_CALL_STACK + void *shadow_call_stack; +#endif }; #define thread_saved_pc(tsk) \ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 478491f07b4f..b3995329d9e5 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -63,6 +63,7 @@ obj-$(CONFIG_CRASH_CORE) += crash_core.o obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o obj-$(CONFIG_ARM64_SSBD) += ssbd.o obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o +obj-$(CONFIG_SHADOW_CALL_STACK) += scs.o obj-y += vdso/ probes/ obj-$(CONFIG_COMPAT_VDSO) += vdso32/ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 214685760e1c..f6762b9ae1e1 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -33,6 +33,9 @@ int main(void) DEFINE(TSK_TI_ADDR_LIMIT, offsetof(struct task_struct, thread_info.addr_limit)); #ifdef CONFIG_ARM64_SW_TTBR0_PAN DEFINE(TSK_TI_TTBR0, offsetof(struct task_struct, thread_info.ttbr0)); +#endif +#ifdef CONFIG_SHADOW_CALL_STACK + DEFINE(TSK_TI_SCS, offsetof(struct task_struct, thread_info.shadow_call_stack)); #endif DEFINE(TSK_STACK, offsetof(struct task_struct, stack)); #ifdef CONFIG_STACKPROTECTOR diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index cf3bd2976e57..1eff08c71403 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -172,6 +172,10 @@ alternative_cb_end apply_ssbd 1, x22, x23 +#ifdef CONFIG_SHADOW_CALL_STACK + ldr x18, [tsk, #TSK_TI_SCS] // Restore shadow call stack + str xzr, [tsk, #TSK_TI_SCS] // Limit visibility of saved SCS +#endif .else add x21, sp, #S_FRAME_SIZE get_current_task tsk @@ -278,6 +282,12 @@ alternative_else_nop_endif ct_user_enter .endif +#ifdef CONFIG_SHADOW_CALL_STACK + .if \el == 0 + str x18, [tsk, #TSK_TI_SCS] // Save shadow call stack + .endif +#endif + #ifdef CONFIG_ARM64_SW_TTBR0_PAN /* * Restore access to TTBR0_EL1. If returning to EL0, no need for SPSR @@ -383,6 +393,9 @@ alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0 .macro irq_stack_entry mov x19, sp // preserve the original sp +#ifdef CONFIG_SHADOW_CALL_STACK + mov x20, x18 // preserve the original shadow stack +#endif /* * Compare sp with the base of the task stack. @@ -400,6 +413,12 @@ alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0 /* switch to the irq stack */ mov sp, x26 + +#ifdef CONFIG_SHADOW_CALL_STACK + /* also switch to the irq shadow stack */ + ldr_this_cpu x18, irq_shadow_call_stack_ptr, x26 +#endif + 9998: .endm @@ -409,6 +428,10 @@ alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0 */ .macro irq_stack_exit mov sp, x19 +#ifdef CONFIG_SHADOW_CALL_STACK + /* x20 is also preserved */ + mov x18, x20 +#endif .endm /* GPRs used by entry code */ @@ -1155,6 +1178,11 @@ ENTRY(cpu_switch_to) ldr lr, [x8] mov sp, x9 msr sp_el0, x1 +#ifdef CONFIG_SHADOW_CALL_STACK + str x18, [x0, #TSK_TI_SCS] + ldr x18, [x1, #TSK_TI_SCS] + str xzr, [x1, #TSK_TI_SCS] // limit visibility of saved SCS +#endif ret ENDPROC(cpu_switch_to) NOKPROBE(cpu_switch_to) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 989b1944cb71..ca561de903d4 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -27,6 +27,7 @@ #include <asm/pgtable-hwdef.h> #include <asm/pgtable.h> #include <asm/page.h> +#include <asm/scs.h> #include <asm/smp.h> #include <asm/sysreg.h> #include <asm/thread_info.h> @@ -424,6 +425,10 @@ __primary_switched: stp xzr, x30, [sp, #-16]! mov x29, sp +#ifdef CONFIG_SHADOW_CALL_STACK + adr_l x18, init_shadow_call_stack // Set shadow call stack +#endif + str_l x21, __fdt_pointer, x5 // Save FDT pointer ldr_l x4, kimage_vaddr // Save the offset between @@ -731,6 +736,10 @@ __secondary_switched: ldr x2, [x0, #CPU_BOOT_TASK] cbz x2, __secondary_too_slow msr sp_el0, x2 +#ifdef CONFIG_SHADOW_CALL_STACK + ldr x18, [x2, #TSK_TI_SCS] // set shadow call stack + str xzr, [x2, #TSK_TI_SCS] // limit visibility of saved SCS +#endif mov x29, #0 mov x30, #0 b secondary_start_kernel diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c index 04a327ccf84d..fe0ca522ff60 100644 --- a/arch/arm64/kernel/irq.c +++ b/arch/arm64/kernel/irq.c @@ -21,6 +21,7 @@ #include <linux/vmalloc.h> #include <asm/daifflags.h> #include <asm/vmap_stack.h> +#include <asm/scs.h> unsigned long irq_err_count; @@ -63,6 +64,7 @@ static void init_irq_stacks(void) void __init init_IRQ(void) { init_irq_stacks(); + scs_init_irq(); irqchip_init(); if (!handle_arch_irq) panic("No interrupt controller found."); diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 71f788cd2b18..5f0aec285848 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -52,6 +52,7 @@ #include <asm/mmu_context.h> #include <asm/processor.h> #include <asm/pointer_auth.h> +#include <asm/scs.h> #include <asm/stacktrace.h> #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) @@ -507,6 +508,7 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, uao_thread_switch(next); ptrauth_thread_switch(next); ssbs_thread_switch(next); + scs_overflow_check(next); /* * Complete any pending TLB or cache maintenance on this CPU in case diff --git a/arch/arm64/kernel/scs.c b/arch/arm64/kernel/scs.c new file mode 100644 index 000000000000..6f255072c9a9 --- /dev/null +++ b/arch/arm64/kernel/scs.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Shadow Call Stack support. + * + * Copyright (C) 2019 Google LLC + */ + +#include <linux/percpu.h> +#include <linux/vmalloc.h> +#include <asm/scs.h> + +DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr); + +#ifndef CONFIG_SHADOW_CALL_STACK_VMAP +DEFINE_PER_CPU(unsigned long [SCS_SIZE/sizeof(long)], irq_shadow_call_stack) + __aligned(SCS_SIZE); +#endif + +void scs_init_irq(void) +{ + int cpu; + + for_each_possible_cpu(cpu) { +#ifdef CONFIG_SHADOW_CALL_STACK_VMAP + unsigned long *p; + + p = __vmalloc_node_range(SCS_SIZE, SCS_SIZE, + VMALLOC_START, VMALLOC_END, + SCS_GFP, PAGE_KERNEL, + 0, cpu_to_node(cpu), + __builtin_return_address(0)); + + per_cpu(irq_shadow_call_stack_ptr, cpu) = p; +#else + per_cpu(irq_shadow_call_stack_ptr, cpu) = + per_cpu(irq_shadow_call_stack, cpu); +#endif /* CONFIG_SHADOW_CALL_STACK_VMAP */ + } +} diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index dc9fe879c279..cc1938a585d2 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -44,6 +44,7 @@ #include <asm/pgtable.h> #include <asm/pgalloc.h> #include <asm/processor.h> +#include <asm/scs.h> #include <asm/smp_plat.h> #include <asm/sections.h> #include <asm/tlbflush.h> @@ -357,6 +358,9 @@ void cpu_die(void) { unsigned int cpu = smp_processor_id(); + /* Save the shadow stack pointer before exiting the idle task */ + scs_save(current); + idle_task_exit(); local_daif_mask();