From c3cdd54c6138871b04dc2306fbfe30ece947ac48 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 27 Dec 2022 13:01:08 +0000 Subject: arm64/ptrace: Use system_supports_tpidr2() to check for TPIDR2 support We have a separate system_supports_tpidr2() to check for TPIDR2 support but were using system_supports_sme() in tls_set(). While these are currently identical let's use the specific check instead so we don't have any surprises in future. Reported-by: Will Deacon Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20221208-arm64-tpidr2-ptrace-feat-v2-1-3760c895a574@kernel.org Signed-off-by: Catalin Marinas --- arch/arm64/kernel/ptrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm64/kernel/ptrace.c') diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 2686ab157601..33d985bb2707 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -683,7 +683,7 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset, unsigned long tls[2]; tls[0] = target->thread.uw.tp_value; - if (system_supports_sme()) + if (system_supports_tpidr2()) tls[1] = target->thread.tpidr2_el0; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, tls, 0, count); @@ -691,7 +691,7 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset, return ret; target->thread.uw.tp_value = tls[0]; - if (system_supports_sme()) + if (system_supports_tpidr2()) target->thread.tpidr2_el0 = tls[1]; return ret; -- cgit v1.2.3 From ce514000da4f4b5f850f3339f805471e5c5c1caf Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 16 Jan 2023 16:04:36 +0000 Subject: arm64/sme: Rename za_state to sme_state In preparation for adding support for storage for ZT0 to the thread_struct rename za_state to sme_state. Since ZT0 is accessible when PSTATE.ZA is set just like ZA itself we will extend the allocation done for ZA to cover it, avoiding the need to further expand task_struct for non-SME tasks. No functional changes. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-1-f2fa0aef982f@kernel.org Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/fpsimd.h | 15 +++++++++------ arch/arm64/include/asm/processor.h | 2 +- arch/arm64/kernel/fpsimd.c | 34 +++++++++++++++++----------------- arch/arm64/kernel/process.c | 13 +++++++------ arch/arm64/kernel/ptrace.c | 6 +++--- arch/arm64/kernel/signal.c | 8 ++++---- arch/arm64/kvm/fpsimd.c | 2 +- 7 files changed, 42 insertions(+), 38 deletions(-) (limited to 'arch/arm64/kernel/ptrace.c') diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index e6fa1e2982c8..2d3fa80cd95d 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -61,7 +61,7 @@ extern void fpsimd_kvm_prepare(void); struct cpu_fp_state { struct user_fpsimd_state *st; void *sve_state; - void *za_state; + void *sme_state; u64 *svcr; unsigned int sve_vl; unsigned int sme_vl; @@ -355,14 +355,17 @@ extern int sme_get_current_vl(void); /* * Return how many bytes of memory are required to store the full SME - * specific state (currently just ZA) for task, given task's currently - * configured vector length. + * specific state for task, given task's currently configured vector + * length. */ -static inline size_t za_state_size(struct task_struct const *task) +static inline size_t sme_state_size(struct task_struct const *task) { unsigned int vl = task_get_sme_vl(task); + size_t size; - return ZA_SIG_REGS_SIZE(sve_vq_from_vl(vl)); + size = ZA_SIG_REGS_SIZE(sve_vq_from_vl(vl)); + + return size; } #else @@ -382,7 +385,7 @@ static inline int sme_max_virtualisable_vl(void) { return 0; } static inline int sme_set_current_vl(unsigned long arg) { return -EINVAL; } static inline int sme_get_current_vl(void) { return -EINVAL; } -static inline size_t za_state_size(struct task_struct const *task) +static inline size_t sme_state_size(struct task_struct const *task) { return 0; } diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index d51b32a69309..3918f2a67970 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -161,7 +161,7 @@ struct thread_struct { enum fp_type fp_type; /* registers FPSIMD or SVE? */ unsigned int fpsimd_cpu; void *sve_state; /* SVE registers, if any */ - void *za_state; /* ZA register, if any */ + void *sme_state; /* ZA and ZT state, if any */ unsigned int vl[ARM64_VEC_MAX]; /* vector length */ unsigned int vl_onexec[ARM64_VEC_MAX]; /* vl after next exec */ unsigned long fault_address; /* fault info */ diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index dcc81e7200d4..9e168a9eb615 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -299,7 +299,7 @@ void task_set_vl_onexec(struct task_struct *task, enum vec_type type, /* * TIF_SME controls whether a task can use SME without trapping while * in userspace, when TIF_SME is set then we must have storage - * alocated in sve_state and za_state to store the contents of both ZA + * alocated in sve_state and sme_state to store the contents of both ZA * and the SVE registers for both streaming and non-streaming modes. * * If both SVCR.ZA and SVCR.SM are disabled then at any point we @@ -429,7 +429,7 @@ static void task_fpsimd_load(void) write_sysreg_s(current->thread.svcr, SYS_SVCR); if (thread_za_enabled(¤t->thread)) - za_load_state(current->thread.za_state); + za_load_state(current->thread.sme_state); if (thread_sm_enabled(¤t->thread)) restore_ffr = system_supports_fa64(); @@ -490,7 +490,7 @@ static void fpsimd_save(void) *svcr = read_sysreg_s(SYS_SVCR); if (*svcr & SVCR_ZA_MASK) - za_save_state(last->za_state); + za_save_state(last->sme_state); /* If we are in streaming mode override regular SVE. */ if (*svcr & SVCR_SM_MASK) { @@ -1257,30 +1257,30 @@ void fpsimd_release_task(struct task_struct *dead_task) #ifdef CONFIG_ARM64_SME /* - * Ensure that task->thread.za_state is allocated and sufficiently large. + * Ensure that task->thread.sme_state is allocated and sufficiently large. * * This function should be used only in preparation for replacing - * task->thread.za_state with new data. The memory is always zeroed + * task->thread.sme_state with new data. The memory is always zeroed * here to prevent stale data from showing through: this is done in * the interest of testability and predictability, the architecture * guarantees that when ZA is enabled it will be zeroed. */ void sme_alloc(struct task_struct *task) { - if (task->thread.za_state) { - memset(task->thread.za_state, 0, za_state_size(task)); + if (task->thread.sme_state) { + memset(task->thread.sme_state, 0, sme_state_size(task)); return; } /* This could potentially be up to 64K. */ - task->thread.za_state = - kzalloc(za_state_size(task), GFP_KERNEL); + task->thread.sme_state = + kzalloc(sme_state_size(task), GFP_KERNEL); } static void sme_free(struct task_struct *task) { - kfree(task->thread.za_state); - task->thread.za_state = NULL; + kfree(task->thread.sme_state); + task->thread.sme_state = NULL; } void sme_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) @@ -1488,7 +1488,7 @@ void do_sme_acc(unsigned long esr, struct pt_regs *regs) sve_alloc(current, false); sme_alloc(current); - if (!current->thread.sve_state || !current->thread.za_state) { + if (!current->thread.sve_state || !current->thread.sme_state) { force_sig(SIGKILL); return; } @@ -1609,7 +1609,7 @@ static void fpsimd_flush_thread_vl(enum vec_type type) void fpsimd_flush_thread(void) { void *sve_state = NULL; - void *za_state = NULL; + void *sme_state = NULL; if (!system_supports_fpsimd()) return; @@ -1634,8 +1634,8 @@ void fpsimd_flush_thread(void) clear_thread_flag(TIF_SME); /* Defer kfree() while in atomic context */ - za_state = current->thread.za_state; - current->thread.za_state = NULL; + sme_state = current->thread.sme_state; + current->thread.sme_state = NULL; fpsimd_flush_thread_vl(ARM64_VEC_SME); current->thread.svcr = 0; @@ -1645,7 +1645,7 @@ void fpsimd_flush_thread(void) put_cpu_fpsimd_context(); kfree(sve_state); - kfree(za_state); + kfree(sme_state); } /* @@ -1711,7 +1711,7 @@ static void fpsimd_bind_task_to_cpu(void) WARN_ON(!system_supports_fpsimd()); last->st = ¤t->thread.uw.fpsimd_state; last->sve_state = current->thread.sve_state; - last->za_state = current->thread.za_state; + last->sme_state = current->thread.sme_state; last->sve_vl = task_get_sve_vl(current); last->sme_vl = task_get_sme_vl(current); last->svcr = ¤t->thread.svcr; diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 269ac1c25ae2..4ce0c4313ec6 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -311,23 +311,24 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) * This may be shortly freed if we exec() or if CLONE_SETTLS * but it's simpler to do it here. To avoid confusing the rest * of the code ensure that we have a sve_state allocated - * whenever za_state is allocated. + * whenever sme_state is allocated. */ if (thread_za_enabled(&src->thread)) { dst->thread.sve_state = kzalloc(sve_state_size(src), GFP_KERNEL); if (!dst->thread.sve_state) return -ENOMEM; - dst->thread.za_state = kmemdup(src->thread.za_state, - za_state_size(src), - GFP_KERNEL); - if (!dst->thread.za_state) { + + dst->thread.sme_state = kmemdup(src->thread.sme_state, + sme_state_size(src), + GFP_KERNEL); + if (!dst->thread.sme_state) { kfree(dst->thread.sve_state); dst->thread.sve_state = NULL; return -ENOMEM; } } else { - dst->thread.za_state = NULL; + dst->thread.sme_state = NULL; clear_tsk_thread_flag(dst, TIF_SME); } diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 2686ab157601..67256e7772e4 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1045,7 +1045,7 @@ static int za_get(struct task_struct *target, if (thread_za_enabled(&target->thread)) { start = end; end = ZA_PT_SIZE(vq); - membuf_write(&to, target->thread.za_state, end - start); + membuf_write(&to, target->thread.sme_state, end - start); } /* Zero any trailing padding */ @@ -1099,7 +1099,7 @@ static int za_set(struct task_struct *target, /* Allocate/reinit ZA storage */ sme_alloc(target); - if (!target->thread.za_state) { + if (!target->thread.sme_state) { ret = -ENOMEM; goto out; } @@ -1124,7 +1124,7 @@ static int za_set(struct task_struct *target, start = ZA_PT_ZA_OFFSET; end = ZA_PT_SIZE(vq); ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, - target->thread.za_state, + target->thread.sme_state, start, end); if (ret) goto out; diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index e0d09bf5b01b..27768809dd3e 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -389,7 +389,7 @@ static int preserve_za_context(struct za_context __user *ctx) * fpsimd_signal_preserve_current_state(). */ err |= __copy_to_user((char __user *)ctx + ZA_SIG_REGS_OFFSET, - current->thread.za_state, + current->thread.sme_state, ZA_SIG_REGS_SIZE(vq)); } @@ -420,7 +420,7 @@ static int restore_za_context(struct user_ctxs *user) /* * Careful: we are about __copy_from_user() directly into - * thread.za_state with preemption enabled, so protection is + * thread.sme_state with preemption enabled, so protection is * needed to prevent a racing context switch from writing stale * registers back over the new data. */ @@ -429,13 +429,13 @@ static int restore_za_context(struct user_ctxs *user) /* From now, fpsimd_thread_switch() won't touch thread.sve_state */ sme_alloc(current); - if (!current->thread.za_state) { + if (!current->thread.sme_state) { current->thread.svcr &= ~SVCR_ZA_MASK; clear_thread_flag(TIF_SME); return -ENOMEM; } - err = __copy_from_user(current->thread.za_state, + err = __copy_from_user(current->thread.sme_state, (char __user const *)user->za + ZA_SIG_REGS_OFFSET, ZA_SIG_REGS_SIZE(vq)); diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 02dd7e9ebd39..235775d0c825 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -143,7 +143,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) fp_state.st = &vcpu->arch.ctxt.fp_regs; fp_state.sve_state = vcpu->arch.sve_state; fp_state.sve_vl = vcpu->arch.sve_max_vl; - fp_state.za_state = NULL; + fp_state.sme_state = NULL; fp_state.svcr = &vcpu->arch.svcr; fp_state.fp_type = &vcpu->arch.fp_type; -- cgit v1.2.3 From f90b529bcbe57c66da2b6a0d3c7c81e8567af63d Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 16 Jan 2023 16:04:47 +0000 Subject: arm64/sme: Implement ZT0 ptrace support Implement support for a new note type NT_ARM64_ZT providing access to ZT0 when implemented. Since ZT0 is a register with constant size this is much simpler than for other SME state. As ZT0 is only accessible when PSTATE.ZA is set writes to ZT0 cause PSTATE.ZA to be set, the main alternative would be to return -EBUSY in this case but this seemed more constructive. Practical users are also going to be working with ZA anyway and have some understanding of the state. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-12-f2fa0aef982f@kernel.org Signed-off-by: Catalin Marinas --- arch/arm64/kernel/ptrace.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/elf.h | 1 + 2 files changed, 55 insertions(+) (limited to 'arch/arm64/kernel/ptrace.c') diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 67256e7772e4..38be7ca202af 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1138,6 +1138,51 @@ out: return ret; } +static int zt_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + if (!system_supports_sme2()) + return -EINVAL; + + /* + * If PSTATE.ZA is not set then ZT will be zeroed when it is + * enabled so report the current register value as zero. + */ + if (thread_za_enabled(&target->thread)) + membuf_write(&to, thread_zt_state(&target->thread), + ZT_SIG_REG_BYTES); + else + membuf_zero(&to, ZT_SIG_REG_BYTES); + + return 0; +} + +static int zt_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int ret; + + if (!system_supports_sme2()) + return -EINVAL; + + if (!thread_za_enabled(&target->thread)) { + sme_alloc(target); + if (!target->thread.sme_state) + return -ENOMEM; + } + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + thread_zt_state(&target->thread), + 0, ZT_SIG_REG_BYTES); + if (ret == 0) + target->thread.svcr |= SVCR_ZA_MASK; + + return ret; +} + #endif /* CONFIG_ARM64_SME */ #ifdef CONFIG_ARM64_PTR_AUTH @@ -1360,6 +1405,7 @@ enum aarch64_regset { #ifdef CONFIG_ARM64_SVE REGSET_SSVE, REGSET_ZA, + REGSET_ZT, #endif #ifdef CONFIG_ARM64_PTR_AUTH REGSET_PAC_MASK, @@ -1467,6 +1513,14 @@ static const struct user_regset aarch64_regsets[] = { .regset_get = za_get, .set = za_set, }, + [REGSET_ZT] = { /* SME ZT */ + .core_note_type = NT_ARM_ZT, + .n = 1, + .size = ZT_SIG_REG_BYTES, + .align = sizeof(u64), + .regset_get = zt_get, + .set = zt_set, + }, #endif #ifdef CONFIG_ARM64_PTR_AUTH [REGSET_PAC_MASK] = { diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index 4c6a8fa5e7ed..68de6f4c4eee 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -434,6 +434,7 @@ typedef struct elf64_shdr { #define NT_ARM_PAC_ENABLED_KEYS 0x40a /* arm64 ptr auth enabled keys (prctl()) */ #define NT_ARM_SSVE 0x40b /* ARM Streaming SVE registers */ #define NT_ARM_ZA 0x40c /* ARM SME ZA registers */ +#define NT_ARM_ZT 0x40d /* ARM SME ZT registers */ #define NT_ARC_V2 0x600 /* ARCv2 accumulator/extra registers */ #define NT_VMCOREDD 0x700 /* Vmcore Device Dump Note */ #define NT_MIPS_DSP 0x800 /* MIPS DSP ASE registers */ -- cgit v1.2.3