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-rw-r--r--arch/arm64/kernel/process.c62
1 files changed, 23 insertions, 39 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index c6b1f3b96f45..223b093c9440 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -58,14 +58,6 @@ unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif
-void soft_restart(unsigned long addr)
-{
- setup_mm_for_reboot();
- cpu_soft_restart(virt_to_phys(cpu_reset), addr);
- /* Should never get here */
- BUG();
-}
-
/*
* Function pointers to optional machine specific functions
*/
@@ -136,9 +128,7 @@ void machine_power_off(void)
/*
* Restart requires that the secondary CPUs stop performing any activity
- * while the primary CPU resets the system. Systems with a single CPU can
- * use soft_restart() as their machine descriptor's .restart hook, since that
- * will cause the only available CPU to reset. Systems with multiple CPUs must
+ * while the primary CPU resets the system. Systems with multiple CPUs must
* provide a HW restart implementation, to ensure that all CPUs reset at once.
* This is required so that any code running after reset on the primary CPU
* doesn't have to co-ordinate with other CPUs to ensure they aren't still
@@ -243,7 +233,8 @@ void release_thread(struct task_struct *dead_task)
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
- fpsimd_preserve_current_state();
+ if (current->mm)
+ fpsimd_preserve_current_state();
*dst = *src;
return 0;
}
@@ -254,35 +245,35 @@ 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);
- unsigned long tls = p->thread.tp_value;
memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
if (likely(!(p->flags & PF_KTHREAD))) {
*childregs = *current_pt_regs();
childregs->regs[0] = 0;
- if (is_compat_thread(task_thread_info(p))) {
- if (stack_start)
+
+ /*
+ * Read the current TLS pointer from tpidr_el0 as it may be
+ * out-of-sync with the saved value.
+ */
+ asm("mrs %0, tpidr_el0" : "=r" (*task_user_tls(p)));
+
+ if (stack_start) {
+ if (is_compat_thread(task_thread_info(p)))
childregs->compat_sp = stack_start;
- } else {
- /*
- * Read the current TLS pointer from tpidr_el0 as it may be
- * out-of-sync with the saved value.
- */
- asm("mrs %0, tpidr_el0" : "=r" (tls));
- if (stack_start) {
- /* 16-byte aligned stack mandatory on AArch64 */
- if (stack_start & 15)
- return -EINVAL;
+ /* 16-byte aligned stack mandatory on AArch64 */
+ else if (stack_start & 15)
+ return -EINVAL;
+ 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)
- tls = childregs->regs[3];
+ p->thread.tp_value = childregs->regs[3];
} else {
memset(childregs, 0, sizeof(struct pt_regs));
childregs->pstate = PSR_MODE_EL1h;
@@ -291,7 +282,6 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
}
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
p->thread.cpu_context.sp = (unsigned long)childregs;
- p->thread.tp_value = tls;
ptrace_hw_copy_thread(p);
@@ -302,18 +292,12 @@ static void tls_thread_switch(struct task_struct *next)
{
unsigned long tpidr, tpidrro;
- if (!is_compat_task()) {
- asm("mrs %0, tpidr_el0" : "=r" (tpidr));
- current->thread.tp_value = tpidr;
- }
+ asm("mrs %0, tpidr_el0" : "=r" (tpidr));
+ *task_user_tls(current) = tpidr;
- if (is_compat_thread(task_thread_info(next))) {
- tpidr = 0;
- tpidrro = next->thread.tp_value;
- } else {
- tpidr = next->thread.tp_value;
- tpidrro = 0;
- }
+ tpidr = *task_user_tls(next);
+ tpidrro = is_compat_thread(task_thread_info(next)) ?
+ next->thread.tp_value : 0;
asm(
" msr tpidr_el0, %0\n"