diff options
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/alternative.c | 51 | ||||
| -rw-r--r-- | arch/arm64/kernel/armv8_deprecated.c | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 177 | ||||
| -rw-r--r-- | arch/arm64/kernel/module.c | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/process.c | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/smp.c | 2 |
8 files changed, 138 insertions, 106 deletions
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 5c4bce4ac381..36fb069fd049 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -122,7 +122,30 @@ static void patch_alternative(struct alt_instr *alt, } } -static void __apply_alternatives(void *alt_region, bool use_linear_alias) +/* + * We provide our own, private D-cache cleaning function so that we don't + * accidentally call into the cache.S code, which is patched by us at + * runtime. + */ +static void clean_dcache_range_nopatch(u64 start, u64 end) +{ + u64 cur, d_size, ctr_el0; + + ctr_el0 = read_sanitised_ftr_reg(SYS_CTR_EL0); + d_size = 4 << cpuid_feature_extract_unsigned_field(ctr_el0, + CTR_DMINLINE_SHIFT); + cur = start & ~(d_size - 1); + do { + /* + * We must clean+invalidate to the PoC in order to avoid + * Cortex-A53 errata 826319, 827319, 824069 and 819472 + * (this corresponds to ARM64_WORKAROUND_CLEAN_CACHE) + */ + asm volatile("dc civac, %0" : : "r" (cur) : "memory"); + } while (cur += d_size, cur < end); +} + +static void __apply_alternatives(void *alt_region, bool is_module) { struct alt_instr *alt; struct alt_region *region = alt_region; @@ -145,7 +168,7 @@ static void __apply_alternatives(void *alt_region, bool use_linear_alias) pr_info_once("patching kernel code\n"); origptr = ALT_ORIG_PTR(alt); - updptr = use_linear_alias ? lm_alias(origptr) : origptr; + updptr = is_module ? origptr : lm_alias(origptr); nr_inst = alt->orig_len / AARCH64_INSN_SIZE; if (alt->cpufeature < ARM64_CB_PATCH) @@ -155,8 +178,20 @@ static void __apply_alternatives(void *alt_region, bool use_linear_alias) alt_cb(alt, origptr, updptr, nr_inst); - flush_icache_range((uintptr_t)origptr, - (uintptr_t)(origptr + nr_inst)); + if (!is_module) { + clean_dcache_range_nopatch((u64)origptr, + (u64)(origptr + nr_inst)); + } + } + + /* + * The core module code takes care of cache maintenance in + * flush_module_icache(). + */ + if (!is_module) { + dsb(ish); + __flush_icache_all(); + isb(); } } @@ -178,7 +213,7 @@ static int __apply_alternatives_multi_stop(void *unused) isb(); } else { BUG_ON(alternatives_applied); - __apply_alternatives(®ion, true); + __apply_alternatives(®ion, false); /* Barriers provided by the cache flushing */ WRITE_ONCE(alternatives_applied, 1); } @@ -192,12 +227,14 @@ void __init apply_alternatives_all(void) stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask); } -void apply_alternatives(void *start, size_t length) +#ifdef CONFIG_MODULES +void apply_alternatives_module(void *start, size_t length) { struct alt_region region = { .begin = start, .end = start + length, }; - __apply_alternatives(®ion, false); + __apply_alternatives(®ion, true); } +#endif diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index 97d45d5151d4..d4707abb2f16 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -234,8 +234,8 @@ static void __init register_insn_emulation_sysctl(void) struct insn_emulation *insn; struct ctl_table *insns_sysctl, *sysctl; - insns_sysctl = kzalloc(sizeof(*sysctl) * (nr_insn_emulated + 1), - GFP_KERNEL); + insns_sysctl = kcalloc(nr_insn_emulated + 1, sizeof(*sysctl), + GFP_KERNEL); raw_spin_lock_irqsave(&insn_emulation_lock, flags); list_for_each_entry(insn, &insn_emulation, node) { diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index d2856b129097..f24892a40d2c 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -937,7 +937,7 @@ static int __init parse_kpti(char *str) __kpti_forced = enabled ? 1 : -1; return 0; } -__setup("kpti=", parse_kpti); +early_param("kpti", parse_kpti); #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ #ifdef CONFIG_ARM64_HW_AFDBM diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 3b527ae46e49..84c68b14f1b2 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -36,12 +36,14 @@ #include <linux/sched/task_stack.h> #include <linux/signal.h> #include <linux/slab.h> +#include <linux/stddef.h> #include <linux/sysctl.h> #include <asm/esr.h> #include <asm/fpsimd.h> #include <asm/cpufeature.h> #include <asm/cputype.h> +#include <asm/processor.h> #include <asm/simd.h> #include <asm/sigcontext.h> #include <asm/sysreg.h> @@ -117,7 +119,6 @@ */ struct fpsimd_last_state_struct { struct user_fpsimd_state *st; - bool sve_in_use; }; static DEFINE_PER_CPU(struct fpsimd_last_state_struct, fpsimd_last_state); @@ -158,19 +159,6 @@ static void sve_free(struct task_struct *task) __sve_free(task); } - -/* Offset of FFR in the SVE register dump */ -static size_t sve_ffr_offset(int vl) -{ - return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET; -} - -static void *sve_pffr(struct task_struct *task) -{ - return (char *)task->thread.sve_state + - sve_ffr_offset(task->thread.sve_vl); -} - static void change_cpacr(u64 val, u64 mask) { u64 cpacr = read_sysreg(CPACR_EL1); @@ -251,31 +239,24 @@ static void task_fpsimd_load(void) WARN_ON(!in_softirq() && !irqs_disabled()); if (system_supports_sve() && test_thread_flag(TIF_SVE)) - sve_load_state(sve_pffr(current), + sve_load_state(sve_pffr(¤t->thread), ¤t->thread.uw.fpsimd_state.fpsr, sve_vq_from_vl(current->thread.sve_vl) - 1); else fpsimd_load_state(¤t->thread.uw.fpsimd_state); - - if (system_supports_sve()) { - /* Toggle SVE trapping for userspace if needed */ - if (test_thread_flag(TIF_SVE)) - sve_user_enable(); - else - sve_user_disable(); - - /* Serialised by exception return to user */ - } } /* - * Ensure current's FPSIMD/SVE storage in thread_struct is up to date - * with respect to the CPU registers. + * Ensure FPSIMD/SVE storage in memory for the loaded context is up to + * date with respect to the CPU registers. * * Softirqs (and preemption) must be disabled. */ -static void task_fpsimd_save(void) +void fpsimd_save(void) { + struct user_fpsimd_state *st = __this_cpu_read(fpsimd_last_state.st); + /* set by fpsimd_bind_task_to_cpu() or fpsimd_bind_state_to_cpu() */ + WARN_ON(!in_softirq() && !irqs_disabled()); if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) { @@ -290,10 +271,9 @@ static void task_fpsimd_save(void) return; } - sve_save_state(sve_pffr(current), - ¤t->thread.uw.fpsimd_state.fpsr); + sve_save_state(sve_pffr(¤t->thread), &st->fpsr); } else - fpsimd_save_state(¤t->thread.uw.fpsimd_state); + fpsimd_save_state(st); } } @@ -588,7 +568,7 @@ int sve_set_vector_length(struct task_struct *task, if (task == current) { local_bh_disable(); - task_fpsimd_save(); + fpsimd_save(); set_thread_flag(TIF_FOREIGN_FPSTATE); } @@ -608,10 +588,8 @@ int sve_set_vector_length(struct task_struct *task, task->thread.sve_vl = vl; out: - if (flags & PR_SVE_VL_INHERIT) - set_tsk_thread_flag(task, TIF_SVE_VL_INHERIT); - else - clear_tsk_thread_flag(task, TIF_SVE_VL_INHERIT); + update_tsk_thread_flag(task, TIF_SVE_VL_INHERIT, + flags & PR_SVE_VL_INHERIT); return 0; } @@ -755,6 +733,33 @@ void sve_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) isb(); } +/* + * Read the pseudo-ZCR used by cpufeatures to identify the supported SVE + * vector length. + * + * Use only if SVE is present. + * This function clobbers the SVE vector length. + */ +u64 read_zcr_features(void) +{ + u64 zcr; + unsigned int vq_max; + + /* + * Set the maximum possible VL, and write zeroes to all other + * bits to see if they stick. + */ + sve_kernel_enable(NULL); + write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL1); + + zcr = read_sysreg_s(SYS_ZCR_EL1); + zcr &= ~(u64)ZCR_ELx_LEN_MASK; /* find sticky 1s outside LEN field */ + vq_max = sve_vq_from_vl(sve_get_vl()); + zcr |= vq_max - 1; /* set LEN field to maximum effective value */ + + return zcr; +} + void __init sve_setup(void) { u64 zcr; @@ -829,7 +834,7 @@ asmlinkage void do_sve_acc(unsigned int esr, struct pt_regs *regs) local_bh_disable(); - task_fpsimd_save(); + fpsimd_save(); fpsimd_to_sve(current); /* Force ret_to_user to reload the registers: */ @@ -882,31 +887,25 @@ asmlinkage void do_fpsimd_exc(unsigned int esr, struct pt_regs *regs) void fpsimd_thread_switch(struct task_struct *next) { + bool wrong_task, wrong_cpu; + if (!system_supports_fpsimd()) return; + + /* Save unsaved fpsimd state, if any: */ + fpsimd_save(); + /* - * Save the current FPSIMD state to memory, but only if whatever is in - * the registers is in fact the most recent userland FPSIMD state of - * 'current'. + * Fix up TIF_FOREIGN_FPSTATE to correctly describe next's + * state. For kernel threads, FPSIMD registers are never loaded + * and wrong_task and wrong_cpu will always be true. */ - if (current->mm) - task_fpsimd_save(); + wrong_task = __this_cpu_read(fpsimd_last_state.st) != + &next->thread.uw.fpsimd_state; + wrong_cpu = next->thread.fpsimd_cpu != smp_processor_id(); - if (next->mm) { - /* - * If we are switching to a task whose most recent userland - * FPSIMD state is already in the registers of *this* cpu, - * we can skip loading the state from memory. Otherwise, set - * the TIF_FOREIGN_FPSTATE flag so the state will be loaded - * upon the next return to userland. - */ - if (__this_cpu_read(fpsimd_last_state.st) == - &next->thread.uw.fpsimd_state - && next->thread.fpsimd_cpu == smp_processor_id()) - clear_tsk_thread_flag(next, TIF_FOREIGN_FPSTATE); - else - set_tsk_thread_flag(next, TIF_FOREIGN_FPSTATE); - } + update_tsk_thread_flag(next, TIF_FOREIGN_FPSTATE, + wrong_task || wrong_cpu); } void fpsimd_flush_thread(void) @@ -972,7 +971,7 @@ void fpsimd_preserve_current_state(void) return; local_bh_disable(); - task_fpsimd_save(); + fpsimd_save(); local_bh_enable(); } @@ -992,14 +991,33 @@ void fpsimd_signal_preserve_current_state(void) * Associate current's FPSIMD context with this cpu * Preemption must be disabled when calling this function. */ -static void fpsimd_bind_to_cpu(void) +void fpsimd_bind_task_to_cpu(void) { struct fpsimd_last_state_struct *last = this_cpu_ptr(&fpsimd_last_state); last->st = ¤t->thread.uw.fpsimd_state; - last->sve_in_use = test_thread_flag(TIF_SVE); current->thread.fpsimd_cpu = smp_processor_id(); + + if (system_supports_sve()) { + /* Toggle SVE trapping for userspace if needed */ + if (test_thread_flag(TIF_SVE)) + sve_user_enable(); + else + sve_user_disable(); + + /* Serialised by exception return to user */ + } +} + +void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st) +{ + struct fpsimd_last_state_struct *last = + this_cpu_ptr(&fpsimd_last_state); + + WARN_ON(!in_softirq() && !irqs_disabled()); + + last->st = st; } /* @@ -1016,7 +1034,7 @@ void fpsimd_restore_current_state(void) if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) { task_fpsimd_load(); - fpsimd_bind_to_cpu(); + fpsimd_bind_task_to_cpu(); } local_bh_enable(); @@ -1039,9 +1057,9 @@ void fpsimd_update_current_state(struct user_fpsimd_state const *state) fpsimd_to_sve(current); task_fpsimd_load(); + fpsimd_bind_task_to_cpu(); - if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) - fpsimd_bind_to_cpu(); + clear_thread_flag(TIF_FOREIGN_FPSTATE); local_bh_enable(); } @@ -1054,29 +1072,12 @@ void fpsimd_flush_task_state(struct task_struct *t) t->thread.fpsimd_cpu = NR_CPUS; } -static inline void fpsimd_flush_cpu_state(void) +void fpsimd_flush_cpu_state(void) { __this_cpu_write(fpsimd_last_state.st, NULL); + set_thread_flag(TIF_FOREIGN_FPSTATE); } -/* - * Invalidate any task SVE state currently held in this CPU's regs. - * - * This is used to prevent the kernel from trying to reuse SVE register data - * that is detroyed by KVM guest enter/exit. This function should go away when - * KVM SVE support is implemented. Don't use it for anything else. - */ -#ifdef CONFIG_ARM64_SVE -void sve_flush_cpu_state(void) -{ - struct fpsimd_last_state_struct const *last = - this_cpu_ptr(&fpsimd_last_state); - - if (last->st && last->sve_in_use) - fpsimd_flush_cpu_state(); -} -#endif /* CONFIG_ARM64_SVE */ - #ifdef CONFIG_KERNEL_MODE_NEON DEFINE_PER_CPU(bool, kernel_neon_busy); @@ -1110,11 +1111,8 @@ void kernel_neon_begin(void) __this_cpu_write(kernel_neon_busy, true); - /* Save unsaved task fpsimd state, if any: */ - if (current->mm) { - task_fpsimd_save(); - set_thread_flag(TIF_FOREIGN_FPSTATE); - } + /* Save unsaved fpsimd state, if any: */ + fpsimd_save(); /* Invalidate any task state remaining in the fpsimd regs: */ fpsimd_flush_cpu_state(); @@ -1236,13 +1234,10 @@ static int fpsimd_cpu_pm_notifier(struct notifier_block *self, { switch (cmd) { case CPU_PM_ENTER: - if (current->mm) - task_fpsimd_save(); + fpsimd_save(); fpsimd_flush_cpu_state(); break; case CPU_PM_EXIT: - if (current->mm) - set_thread_flag(TIF_FOREIGN_FPSTATE); break; case CPU_PM_ENTER_FAILED: default: diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c index 155fd91e78f4..f0f27aeefb73 100644 --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c @@ -448,9 +448,8 @@ int module_finalize(const Elf_Ehdr *hdr, const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++) { - if (strcmp(".altinstructions", secstrs + s->sh_name) == 0) { - apply_alternatives((void *)s->sh_addr, s->sh_size); - } + if (strcmp(".altinstructions", secstrs + s->sh_name) == 0) + apply_alternatives_module((void *)s->sh_addr, s->sh_size); #ifdef CONFIG_ARM64_MODULE_PLTS if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE) && !strcmp(".text.ftrace_trampoline", secstrs + s->sh_name)) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index f08a2ed9db0d..e10bc363f533 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -59,7 +59,7 @@ #include <asm/processor.h> #include <asm/stacktrace.h> -#ifdef CONFIG_CC_STACKPROTECTOR +#ifdef CONFIG_STACKPROTECTOR #include <linux/stackprotector.h> unsigned long __stack_chk_guard __read_mostly; EXPORT_SYMBOL(__stack_chk_guard); diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index bd732644c2f6..5c338ce5a7fa 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -44,6 +44,7 @@ #include <asm/compat.h> #include <asm/cpufeature.h> #include <asm/debug-monitors.h> +#include <asm/fpsimd.h> #include <asm/pgtable.h> #include <asm/stacktrace.h> #include <asm/syscall.h> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index f3e2e3aec0b0..2faa9863d2e5 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -179,7 +179,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) * This is the secondary CPU boot entry. We're using this CPUs * idle thread stack, but a set of temporary page tables. */ -asmlinkage void secondary_start_kernel(void) +asmlinkage notrace void secondary_start_kernel(void) { u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK; struct mm_struct *mm = &init_mm; |
