static int compat_vfp_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct user_fpsimd_state *uregs;
compat_ulong_t fpscr;
int ret;
if (pos + count > VFP_STATE_SIZE)
return -EIO;
uregs = &target->thread.fpsimd_state.user_fpsimd;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
VFP_STATE_SIZE - sizeof(compat_ulong_t));
if (count && !ret) {
ret = get_user(fpscr, (compat_ulong_t *)ubuf);
uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
}
fpsimd_flush_task_state(target);
return ret;
}
void fpsimd_flush_thread(void)
{
preempt_disable();
memset(¤t->thread.fpsimd_state, 0, sizeof(struct fpsimd_state));
fpsimd_flush_task_state(current);
set_thread_flag(TIF_FOREIGN_FPSTATE);
preempt_enable();
}
void fpsimd_flush_thread(void)
{
if (!system_supports_fpsimd())
return;
preempt_disable();
memset(¤t->thread.fpsimd_state, 0, sizeof(struct fpsimd_state));
fpsimd_flush_task_state(current);
set_thread_flag(TIF_FOREIGN_FPSTATE);
preempt_enable();
}
static int fpr_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;
struct user_fpsimd_state newstate;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
if (ret)
return ret;
target->thread.fpsimd_state.user_fpsimd = newstate;
fpsimd_flush_task_state(target);
return ret;
}
int sve_set_vector_length(struct task_struct *task,
unsigned long vl, unsigned long flags)
{
if (flags & ~(unsigned long)(PR_SVE_VL_INHERIT |
PR_SVE_SET_VL_ONEXEC))
return -EINVAL;
if (!sve_vl_valid(vl))
return -EINVAL;
/*
* Clamp to the maximum vector length that VL-agnostic SVE code can
* work with. A flag may be assigned in the future to allow setting
* of larger vector lengths without confusing older software.
*/
if (vl > SVE_VL_ARCH_MAX)
vl = SVE_VL_ARCH_MAX;
vl = find_supported_vector_length(vl);
if (flags & (PR_SVE_VL_INHERIT |
PR_SVE_SET_VL_ONEXEC))
task->thread.sve_vl_onexec = vl;
else
/* Reset VL to system default on next exec: */
task->thread.sve_vl_onexec = 0;
/* Only actually set the VL if not deferred: */
if (flags & PR_SVE_SET_VL_ONEXEC)
goto out;
if (vl == task->thread.sve_vl)
goto out;
/*
* To ensure the FPSIMD bits of the SVE vector registers are preserved,
* write any live register state back to task_struct, and convert to a
* non-SVE thread.
*/
if (task == current) {
local_bh_disable();
fpsimd_save();
set_thread_flag(TIF_FOREIGN_FPSTATE);
}
fpsimd_flush_task_state(task);
if (test_and_clear_tsk_thread_flag(task, TIF_SVE))
sve_to_fpsimd(task);
if (task == current)
local_bh_enable();
/*
* Force reallocation of task SVE state to the correct size
* on next use:
*/
sve_free(task);
task->thread.sve_vl = vl;
out:
update_tsk_thread_flag(task, TIF_SVE_VL_INHERIT,
flags & PR_SVE_VL_INHERIT);
return 0;
}
int copy_thread(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p)
{
struct pt_regs *childregs = task_pt_regs(p);
memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
/*
* Unalias p->thread.sve_state (if any) from the parent task
* and disable discard SVE state for p:
*/
clear_tsk_thread_flag(p, TIF_SVE);
p->thread.sve_state = NULL;
/*
* In case p was allocated the same task_struct pointer as some
* other recently-exited task, make sure p is disassociated from
* any cpu that may have run that now-exited task recently.
* Otherwise we could erroneously skip reloading the FPSIMD
* registers for p.
*/
fpsimd_flush_task_state(p);
if (likely(!(p->flags & PF_KTHREAD))) {
*childregs = *current_pt_regs();
childregs->regs[0] = 0;
/*
* Read the current TLS pointer from tpidr_el0 as it may be
* out-of-sync with the saved value.
*/
*task_user_tls(p) = read_sysreg(tpidr_el0);
if (stack_start) {
if (is_compat_thread(task_thread_info(p)))
childregs->compat_sp = stack_start;
else
childregs->sp = stack_start;
}
/*
* If a TLS pointer was passed to clone (4th argument), use it
* for the new thread.
*/
if (clone_flags & CLONE_SETTLS)
p->thread.uw.tp_value = childregs->regs[3];
} else {
memset(childregs, 0, sizeof(struct pt_regs));
childregs->pstate = PSR_MODE_EL1h;
if (IS_ENABLED(CONFIG_ARM64_UAO) &&
cpus_have_const_cap(ARM64_HAS_UAO))
childregs->pstate |= PSR_UAO_BIT;
if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE)
childregs->pstate |= PSR_SSBS_BIT;
if (system_uses_irq_prio_masking())
childregs->pmr_save = GIC_PRIO_IRQON;
p->thread.cpu_context.x19 = stack_start;
p->thread.cpu_context.x20 = stk_sz;
}
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
p->thread.cpu_context.sp = (unsigned long)childregs;
ptrace_hw_copy_thread(p);
return 0;
}
