diff options
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/alternative.h | 86 | ||||
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 50 | ||||
| -rw-r--r-- | arch/arm64/include/asm/barrier.h | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/efi.h | 33 | ||||
| -rw-r--r-- | arch/arm64/include/asm/esr.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/futex.h | 17 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kernel-pgtable.h | 28 | ||||
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/mmu_context.h | 53 | ||||
| -rw-r--r-- | arch/arm64/include/asm/module.h | 5 | ||||
| -rw-r--r-- | arch/arm64/include/asm/spinlock.h | 10 | ||||
| -rw-r--r-- | arch/arm64/include/asm/thread_info.h | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/topology.h | 9 | ||||
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 175 |
15 files changed, 417 insertions, 68 deletions
diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h index beccbdefa106..55101bd86b98 100644 --- a/arch/arm64/include/asm/alternative.h +++ b/arch/arm64/include/asm/alternative.h @@ -2,6 +2,7 @@ #define __ASM_ALTERNATIVE_H #include <asm/cpufeature.h> +#include <asm/insn.h> #ifndef __ASSEMBLY__ @@ -90,26 +91,15 @@ void apply_alternatives(void *start, size_t length); .endm /* - * Begin an alternative code sequence. + * Alternative sequences * - * The code that follows this macro will be assembled and linked as - * normal. There are no restrictions on this code. - */ -.macro alternative_if_not cap, enable = 1 - .if \enable - .pushsection .altinstructions, "a" - altinstruction_entry 661f, 663f, \cap, 662f-661f, 664f-663f - .popsection -661: - .endif -.endm - -/* - * Provide the alternative code sequence. + * The code for the case where the capability is not present will be + * assembled and linked as normal. There are no restrictions on this + * code. * - * The code that follows this macro is assembled into a special - * section to be used for dynamic patching. Code that follows this - * macro must: + * The code for the case where the capability is present will be + * assembled into a special section to be used for dynamic patching. + * Code for that case must: * * 1. Be exactly the same length (in bytes) as the default code * sequence. @@ -118,27 +108,71 @@ void apply_alternatives(void *start, size_t length); * alternative sequence it is defined in (branches into an * alternative sequence are not fixed up). */ -.macro alternative_else, enable = 1 - .if \enable -662: .pushsection .altinstr_replacement, "ax" -663: + +/* + * Begin an alternative code sequence. + */ +.macro alternative_if_not cap + .set .Lasm_alt_mode, 0 + .pushsection .altinstructions, "a" + altinstruction_entry 661f, 663f, \cap, 662f-661f, 664f-663f + .popsection +661: +.endm + +.macro alternative_if cap + .set .Lasm_alt_mode, 1 + .pushsection .altinstructions, "a" + altinstruction_entry 663f, 661f, \cap, 664f-663f, 662f-661f + .popsection + .pushsection .altinstr_replacement, "ax" + .align 2 /* So GAS knows label 661 is suitably aligned */ +661: +.endm + +/* + * Provide the other half of the alternative code sequence. + */ +.macro alternative_else +662: + .if .Lasm_alt_mode==0 + .pushsection .altinstr_replacement, "ax" + .else + .popsection .endif +663: .endm /* * Complete an alternative code sequence. */ -.macro alternative_endif, enable = 1 - .if \enable -664: .popsection +.macro alternative_endif +664: + .if .Lasm_alt_mode==0 + .popsection + .endif .org . - (664b-663b) + (662b-661b) .org . - (662b-661b) + (664b-663b) - .endif +.endm + +/* + * Provides a trivial alternative or default sequence consisting solely + * of NOPs. The number of NOPs is chosen automatically to match the + * previous case. + */ +.macro alternative_else_nop_endif +alternative_else + nops (662b-661b) / AARCH64_INSN_SIZE +alternative_endif .endm #define _ALTERNATIVE_CFG(insn1, insn2, cap, cfg, ...) \ alternative_insn insn1, insn2, cap, IS_ENABLED(cfg) +.macro user_alt, label, oldinstr, newinstr, cond +9999: alternative_insn "\oldinstr", "\newinstr", \cond + _ASM_EXTABLE 9999b, \label +.endm /* * Generate the assembly for UAO alternatives with exception table entries. diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 290e13428f4a..d8855ca6068a 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -24,6 +24,7 @@ #define __ASM_ASSEMBLER_H #include <asm/asm-offsets.h> +#include <asm/cpufeature.h> #include <asm/page.h> #include <asm/pgtable-hwdef.h> #include <asm/ptrace.h> @@ -52,6 +53,15 @@ msr daifclr, #2 .endm + .macro save_and_disable_irq, flags + mrs \flags, daif + msr daifset, #2 + .endm + + .macro restore_irq, flags + msr daif, \flags + .endm + /* * Enable and disable debug exceptions. */ @@ -98,6 +108,15 @@ .endm /* + * NOP sequence + */ + .macro nops, num + .rept \num + nop + .endr + .endm + +/* * Emit an entry into the exception table */ .macro _asm_extable, from, to @@ -273,7 +292,16 @@ lr .req x30 // link register add \size, \kaddr, \size sub \tmp2, \tmp1, #1 bic \kaddr, \kaddr, \tmp2 -9998: dc \op, \kaddr +9998: + .if (\op == cvau || \op == cvac) +alternative_if_not ARM64_WORKAROUND_CLEAN_CACHE + dc \op, \kaddr +alternative_else + dc civac, \kaddr +alternative_endif + .else + dc \op, \kaddr + .endif add \kaddr, \kaddr, \tmp1 cmp \kaddr, \size b.lo 9998b @@ -352,4 +380,24 @@ lr .req x30 // link register movk \reg, :abs_g0_nc:\val .endm +/* + * Return the current thread_info. + */ + .macro get_thread_info, rd + mrs \rd, sp_el0 + .endm + +/* + * Errata workaround post TTBR0_EL1 update. + */ + .macro post_ttbr0_update_workaround +#ifdef CONFIG_CAVIUM_ERRATUM_27456 +alternative_if ARM64_WORKAROUND_CAVIUM_27456 + ic iallu + dsb nsh + isb +alternative_else_nop_endif +#endif + .endm + #endif /* __ASM_ASSEMBLER_H */ diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index 9622eb48f894..c5dbc5cb8f10 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -20,6 +20,9 @@ #ifndef __ASSEMBLY__ +#define __nops(n) ".rept " #n "\nnop\n.endr\n" +#define nops(n) asm volatile(__nops(n)) + #define sev() asm volatile("sev" : : : "memory") #define wfe() asm volatile("wfe" : : : "memory") #define wfi() asm volatile("wfi" : : : "memory") diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 1695f77d8bf2..8e1f826caf99 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -189,6 +189,12 @@ static inline bool system_supports_mixed_endian_el0(void) return id_aa64mmfr0_mixed_endian_el0(read_system_reg(SYS_ID_AA64MMFR0_EL1)); } +static inline bool system_uses_ttbr0_pan(void) +{ + return IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN) && + !cpus_have_cap(ARM64_HAS_PAN); +} + #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index ef572206f1c3..932f5a56d1a6 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -1,8 +1,11 @@ #ifndef _ASM_EFI_H #define _ASM_EFI_H +#include <asm/cpufeature.h> #include <asm/io.h> +#include <asm/mmu_context.h> #include <asm/neon.h> +#include <asm/tlbflush.h> #ifdef CONFIG_EFI extern void efi_init(void); @@ -10,6 +13,8 @@ extern void efi_init(void); #define efi_init() #endif +int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md); + #define efi_call_virt(f, ...) \ ({ \ efi_##f##_t *__f; \ @@ -63,6 +68,34 @@ extern void efi_init(void); * Services are enabled and the EFI_RUNTIME_SERVICES bit set. */ +static inline void efi_set_pgd(struct mm_struct *mm) +{ + __switch_mm(mm); + + if (system_uses_ttbr0_pan()) { + if (mm != current->active_mm) { + /* + * Update the current thread's saved ttbr0 since it is + * restored as part of a return from exception. Set + * the hardware TTBR0_EL1 using cpu_switch_mm() + * directly to enable potential errata workarounds. + */ + update_saved_ttbr0(current, mm); + cpu_switch_mm(mm->pgd, mm); + } else { + /* + * Defer the switch to the current thread's TTBR0_EL1 + * until uaccess_enable(). Restore the current + * thread's saved ttbr0 corresponding to its active_mm + * (if different from init_mm). + */ + cpu_set_reserved_ttbr0(); + if (current->active_mm != &init_mm) + update_saved_ttbr0(current, current->active_mm); + } + } +} + void efi_virtmap_load(void); void efi_virtmap_unload(void); diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index 77eeb2cc648f..f772e15c4766 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -74,6 +74,7 @@ #define ESR_ELx_EC_SHIFT (26) #define ESR_ELx_EC_MASK (UL(0x3F) << ESR_ELx_EC_SHIFT) +#define ESR_ELx_EC(esr) (((esr) & ESR_ELx_EC_MASK) >> ESR_ELx_EC_SHIFT) #define ESR_ELx_IL (UL(1) << 25) #define ESR_ELx_ISS_MASK (ESR_ELx_IL - 1) diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h index f2585cdd32c2..85c4a8981d47 100644 --- a/arch/arm64/include/asm/futex.h +++ b/arch/arm64/include/asm/futex.h @@ -21,15 +21,12 @@ #include <linux/futex.h> #include <linux/uaccess.h> -#include <asm/alternative.h> -#include <asm/cpufeature.h> #include <asm/errno.h> -#include <asm/sysreg.h> #define __futex_atomic_op(insn, ret, oldval, uaddr, tmp, oparg) \ +do { \ + uaccess_enable(); \ asm volatile( \ - ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, \ - CONFIG_ARM64_PAN) \ " prfm pstl1strm, %2\n" \ "1: ldxr %w1, %2\n" \ insn "\n" \ @@ -44,11 +41,11 @@ " .popsection\n" \ _ASM_EXTABLE(1b, 4b) \ _ASM_EXTABLE(2b, 4b) \ - ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, \ - CONFIG_ARM64_PAN) \ : "=&r" (ret), "=&r" (oldval), "+Q" (*uaddr), "=&r" (tmp) \ : "r" (oparg), "Ir" (-EFAULT) \ - : "memory") + : "memory"); \ + uaccess_disable(); \ +} while (0) static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) @@ -118,8 +115,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) return -EFAULT; + uaccess_enable(); asm volatile("// futex_atomic_cmpxchg_inatomic\n" -ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN) " prfm pstl1strm, %2\n" "1: ldxr %w1, %2\n" " sub %w3, %w1, %w4\n" @@ -134,10 +131,10 @@ ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN) " .popsection\n" _ASM_EXTABLE(1b, 4b) _ASM_EXTABLE(2b, 4b) -ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) : "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp) : "r" (oldval), "r" (newval), "Ir" (-EFAULT) : "memory"); + uaccess_disable(); *uval = val; return ret; diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h index 5c6375d8528b..7803343e5881 100644 --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -19,6 +19,8 @@ #ifndef __ASM_KERNEL_PGTABLE_H #define __ASM_KERNEL_PGTABLE_H +#include <asm/pgtable.h> +#include <asm/sparsemem.h> /* * The linear mapping and the start of memory are both 2M aligned (per @@ -53,6 +55,12 @@ #define SWAPPER_DIR_SIZE (SWAPPER_PGTABLE_LEVELS * PAGE_SIZE) #define IDMAP_DIR_SIZE (IDMAP_PGTABLE_LEVELS * PAGE_SIZE) +#ifdef CONFIG_ARM64_SW_TTBR0_PAN +#define RESERVED_TTBR0_SIZE (PAGE_SIZE) +#else +#define RESERVED_TTBR0_SIZE (0) +#endif + /* Initial memory map size */ #if ARM64_SWAPPER_USES_SECTION_MAPS #define SWAPPER_BLOCK_SHIFT SECTION_SHIFT @@ -86,10 +94,24 @@ * (64k granule), or a multiple that can be mapped using contiguous bits * in the page tables: 32 * PMD_SIZE (16k granule) */ -#ifdef CONFIG_ARM64_64K_PAGES -#define ARM64_MEMSTART_ALIGN SZ_512M +#if defined(CONFIG_ARM64_4K_PAGES) +#define ARM64_MEMSTART_SHIFT PUD_SHIFT +#elif defined(CONFIG_ARM64_16K_PAGES) +#define ARM64_MEMSTART_SHIFT (PMD_SHIFT + 5) +#else +#define ARM64_MEMSTART_SHIFT PMD_SHIFT +#endif + +/* + * sparsemem vmemmap imposes an additional requirement on the alignment of + * memstart_addr, due to the fact that the base of the vmemmap region + * has a direct correspondence, and needs to appear sufficiently aligned + * in the virtual address space. + */ +#if defined(CONFIG_SPARSEMEM_VMEMMAP) && ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS +#define ARM64_MEMSTART_ALIGN (1UL << SECTION_SIZE_BITS) #else -#define ARM64_MEMSTART_ALIGN SZ_1G +#define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT) #endif #endif /* __ASM_KERNEL_PGTABLE_H */ diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index d776037d199f..ae11e8fdbfd2 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -196,7 +196,11 @@ static inline void *phys_to_virt(phys_addr_t x) #define ARCH_PFN_OFFSET ((unsigned long)PHYS_PFN_OFFSET) #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT) -#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) +#define _virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) + +#define _virt_addr_is_linear(kaddr) (((u64)(kaddr)) >= PAGE_OFFSET) +#define virt_addr_valid(kaddr) (_virt_addr_is_linear(kaddr) && \ + _virt_addr_valid(kaddr)) #endif diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index a00f7cf35bbd..e53d30c6f779 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -23,6 +23,7 @@ #include <linux/sched.h> #include <asm/cacheflush.h> +#include <asm/cpufeature.h> #include <asm/proc-fns.h> #include <asm-generic/mm_hooks.h> #include <asm/cputype.h> @@ -113,7 +114,7 @@ static inline void cpu_uninstall_idmap(void) local_flush_tlb_all(); cpu_set_default_tcr_t0sz(); - if (mm != &init_mm) + if (mm != &init_mm && !system_uses_ttbr0_pan()) cpu_switch_mm(mm->pgd, mm); } @@ -173,20 +174,26 @@ enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) { } -/* - * This is the actual mm switch as far as the scheduler - * is concerned. No registers are touched. We avoid - * calling the CPU specific function when the mm hasn't - * actually changed. - */ -static inline void -switch_mm(struct mm_struct *prev, struct mm_struct *next, - struct task_struct *tsk) +#ifdef CONFIG_ARM64_SW_TTBR0_PAN +static inline void update_saved_ttbr0(struct task_struct *tsk, + struct mm_struct *mm) { - unsigned int cpu = smp_processor_id(); + if (system_uses_ttbr0_pan()) { + BUG_ON(mm->pgd == swapper_pg_dir); + task_thread_info(tsk)->ttbr0 = + virt_to_phys(mm->pgd) | ASID(mm) << 48; + } +} +#else +static inline void update_saved_ttbr0(struct task_struct *tsk, + struct mm_struct *mm) +{ +} +#endif - if (prev == next) - return; +static inline void __switch_mm(struct mm_struct *next) +{ + unsigned int cpu = smp_processor_id(); /* * init_mm.pgd does not contain any user mappings and it is always @@ -200,7 +207,25 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next, check_and_switch_context(next, cpu); } +static inline void +switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) +{ + if (prev != next) + __switch_mm(next); + + /* + * Update the saved TTBR0_EL1 of the scheduled-in task as the previous + * value may have not been initialised yet (activate_mm caller) or the + * ASID has changed since the last run (following the context switch + * of another thread of the same process). Avoid setting the reserved + * TTBR0_EL1 to swapper_pg_dir (init_mm; e.g. via idle_task_exit). + */ + if (next != &init_mm) + update_saved_ttbr0(tsk, next); +} + #define deactivate_mm(tsk,mm) do { } while (0) -#define activate_mm(prev,next) switch_mm(prev, next, NULL) +#define activate_mm(prev,next) switch_mm(prev, next, current) #endif diff --git a/arch/arm64/include/asm/module.h b/arch/arm64/include/asm/module.h index e12af6754634..06ff7fd9e81f 100644 --- a/arch/arm64/include/asm/module.h +++ b/arch/arm64/include/asm/module.h @@ -17,6 +17,7 @@ #define __ASM_MODULE_H #include <asm-generic/module.h> +#include <asm/memory.h> #define MODULE_ARCH_VERMAGIC "aarch64" @@ -32,6 +33,10 @@ u64 module_emit_plt_entry(struct module *mod, const Elf64_Rela *rela, Elf64_Sym *sym); #ifdef CONFIG_RANDOMIZE_BASE +#ifdef CONFIG_MODVERSIONS +#define ARCH_RELOCATES_KCRCTAB +#define reloc_start (kimage_vaddr - KIMAGE_VADDR) +#endif extern u64 module_alloc_base; #else #define module_alloc_base ((u64)_etext - MODULES_VSIZE) diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h index 53ee219e76a7..43a66881fd57 100644 --- a/arch/arm64/include/asm/spinlock.h +++ b/arch/arm64/include/asm/spinlock.h @@ -37,13 +37,17 @@ static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) "2: ldaxr %w0, %2\n" " eor %w1, %w0, %w0, ror #16\n" " cbnz %w1, 1b\n" + /* Serialise against any concurrent lockers */ ARM64_LSE_ATOMIC_INSN( /* LL/SC */ " stxr %w1, %w0, %2\n" -" cbnz %w1, 2b\n", /* Serialise against any concurrent lockers */ - /* LSE atomics */ " nop\n" -" nop\n") +" nop\n", + /* LSE atomics */ +" mov %w1, %w0\n" +" cas %w0, %w0, %2\n" +" eor %w1, %w1, %w0\n") +" cbnz %w1, 2b\n" : "=&r" (lockval), "=&r" (tmp), "+Q" (*lock) : : "memory"); diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index abd64bd1f6d9..794d22603f04 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -48,6 +48,9 @@ struct thread_info { unsigned long flags; /* low level flags */ mm_segment_t addr_limit; /* address limit */ struct task_struct *task; /* main task structure */ +#ifdef CONFIG_ARM64_SW_TTBR0_PAN + u64 ttbr0; /* saved TTBR0_EL1 */ +#endif int preempt_count; /* 0 => preemptable, <0 => bug */ int cpu; /* cpu */ }; diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h index a3e9d6fdbf21..bbd362cd1ed1 100644 --- a/arch/arm64/include/asm/topology.h +++ b/arch/arm64/include/asm/topology.h @@ -22,6 +22,15 @@ void init_cpu_topology(void); void store_cpu_topology(unsigned int cpuid); const struct cpumask *cpu_coregroup_mask(int cpu); +struct sched_domain; +#ifdef CONFIG_CPU_FREQ +#define arch_scale_freq_capacity cpufreq_scale_freq_capacity +extern unsigned long cpufreq_scale_freq_capacity(struct sched_domain *sd, int cpu); +extern unsigned long cpufreq_scale_max_freq_capacity(int cpu); +#endif +#define arch_scale_cpu_capacity scale_cpu_capacity +extern unsigned long scale_cpu_capacity(struct sched_domain *sd, int cpu); + #include <asm-generic/topology.h> #endif /* _ASM_ARM_TOPOLOGY_H */ diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index c3d445b42351..efafdf39cb3b 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -18,16 +18,20 @@ #ifndef __ASM_UACCESS_H #define __ASM_UACCESS_H +#include <asm/alternative.h> +#include <asm/kernel-pgtable.h> +#include <asm/sysreg.h> + +#ifndef __ASSEMBLY__ + /* * User space memory access functions */ #include <linux/string.h> #include <linux/thread_info.h> -#include <asm/alternative.h> #include <asm/cpufeature.h> #include <asm/ptrace.h> -#include <asm/sysreg.h> #include <asm/errno.h> #include <asm/memory.h> #include <asm/compiler.h> @@ -124,6 +128,99 @@ static inline void set_fs(mm_segment_t fs) " .popsection\n" /* + * User access enabling/disabling. + */ +#ifdef CONFIG_ARM64_SW_TTBR0_PAN +static inline void __uaccess_ttbr0_disable(void) +{ + unsigned long ttbr; + + /* reserved_ttbr0 placed at the end of swapper_pg_dir */ + ttbr = read_sysreg(ttbr1_el1) + SWAPPER_DIR_SIZE; + write_sysreg(ttbr, ttbr0_el1); + isb(); +} + +static inline void __uaccess_ttbr0_enable(void) +{ + unsigned long flags; + + /* + * Disable interrupts to avoid preemption between reading the 'ttbr0' + * variable and the MSR. A context switch could trigger an ASID + * roll-over and an update of 'ttbr0'. + */ + local_irq_save(flags); + write_sysreg(current_thread_info()->ttbr0, ttbr0_el1); + isb(); + local_irq_restore(flags); +} + +static inline bool uaccess_ttbr0_disable(void) +{ + if (!system_uses_ttbr0_pan()) + return false; + __uaccess_ttbr0_disable(); + return true; +} + +static inline bool uaccess_ttbr0_enable(void) +{ + if (!system_uses_ttbr0_pan()) + return false; + __uaccess_ttbr0_enable(); + return true; +} +#else +static inline bool uaccess_ttbr0_disable(void) +{ + return false; +} + +static inline bool uaccess_ttbr0_enable(void) +{ + return false; +} +#endif + +#define __uaccess_disable(alt) \ +do { \ + if (!uaccess_ttbr0_disable()) \ + asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), alt, \ + CONFIG_ARM64_PAN)); \ +} while (0) + +#define __uaccess_enable(alt) \ +do { \ + if (!uaccess_ttbr0_enable()) \ + asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt, \ + CONFIG_ARM64_PAN)); \ +} while (0) + +static inline void uaccess_disable(void) +{ + __uaccess_disable(ARM64_HAS_PAN); +} + +static inline void uaccess_enable(void) +{ + __uaccess_enable(ARM64_HAS_PAN); +} + +/* + * These functions are no-ops when UAO is present. + */ +static inline void uaccess_disable_not_uao(void) +{ + __uaccess_disable(ARM64_ALT_PAN_NOT_UAO); +} + +static inline void uaccess_enable_not_uao(void) +{ + __uaccess_enable(ARM64_ALT_PAN_NOT_UAO); +} + +/* * The "__xxx" versions of the user access functions do not verify the address * space - it must have been done previously with a separate "access_ok()" * call. @@ -150,8 +247,7 @@ static inline void set_fs(mm_segment_t fs) do { \ unsigned long __gu_val; \ __chk_user_ptr(ptr); \ - asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_ALT_PAN_NOT_UAO,\ - CONFIG_ARM64_PAN)); \ + uaccess_enable_not_uao(); \ switch (sizeof(*(ptr))) { \ case 1: \ __get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \ @@ -172,9 +268,8 @@ do { \ default: \ BUILD_BUG(); \ } \ + uaccess_disable_not_uao(); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ - asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_ALT_PAN_NOT_UAO,\ - CONFIG_ARM64_PAN)); \ } while (0) #define __get_user(x, ptr) \ @@ -219,8 +314,7 @@ do { \ do { \ __typeof__(*(ptr)) __pu_val = (x); \ __chk_user_ptr(ptr); \ - asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_ALT_PAN_NOT_UAO,\ - CONFIG_ARM64_PAN)); \ + uaccess_enable_not_uao(); \ switch (sizeof(*(ptr))) { \ case 1: \ __put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \ @@ -241,8 +335,7 @@ do { \ default: \ BUILD_BUG(); \ } \ - asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_ALT_PAN_NOT_UAO,\ - CONFIG_ARM64_PAN)); \ + uaccess_disable_not_uao(); \ } while (0) #define __put_user(x, ptr) \ @@ -327,4 +420,66 @@ extern long strncpy_from_user(char *dest, const char __user *src, long count); extern __must_check long strlen_user(const char __user *str); extern __must_check long strnlen_user(const char __user *str, long n); +#else /* __ASSEMBLY__ */ + +#include <asm/assembler.h> + +/* + * User access enabling/disabling macros. + */ +#ifdef CONFIG_ARM64_SW_TTBR0_PAN + .macro __uaccess_ttbr0_disable, tmp1 + mrs \tmp1, ttbr1_el1 // swapper_pg_dir + add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir + msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 + isb + .endm + + .macro __uaccess_ttbr0_enable, tmp1 + get_thread_info \tmp1 + ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1 + msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1 + isb + .endm + + .macro uaccess_ttbr0_disable, tmp1 +alternative_if_not ARM64_HAS_PAN + __uaccess_ttbr0_disable \tmp1 +alternative_else_nop_endif + .endm + + .macro uaccess_ttbr0_enable, tmp1, tmp2 +alternative_if_not ARM64_HAS_PAN + save_and_disable_irq \tmp2 // avoid preemption + __uaccess_ttbr0_enable \tmp1 + restore_irq \tmp2 +alternative_else_nop_endif + .endm +#else + .macro uaccess_ttbr0_disable, tmp1 + .endm + + .macro uaccess_ttbr0_enable, tmp1, tmp2 + .endm +#endif + +/* + * These macros are no-ops when UAO is present. + */ + .macro uaccess_disable_not_uao, tmp1 + uaccess_ttbr0_disable \tmp1 +alternative_if ARM64_ALT_PAN_NOT_UAO + SET_PSTATE_PAN(1) +alternative_else_nop_endif + .endm + + .macro uaccess_enable_not_uao, tmp1, tmp2 + uaccess_ttbr0_enable \tmp1, \tmp2 +alternative_if ARM64_ALT_PAN_NOT_UAO + SET_PSTATE_PAN(0) +alternative_else_nop_endif + .endm + +#endif /* __ASSEMBLY__ */ + #endif /* __ASM_UACCESS_H */ |