// SPDX-License-Identifier: GPL-2.0
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/prctl.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/sched/idle.h>
#include <linux/sched/debug.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/random.h>
#include <linux/user-return-notifier.h>
#include <linux/dmi.h>
#include <linux/utsname.h>
#include <linux/stackprotector.h>
#include <linux/cpuidle.h>
#include <linux/acpi.h>
#include <linux/elf-randomize.h>
#include <trace/events/power.h>
#include <linux/hw_breakpoint.h>
#include <asm/cpu.h>
#include <asm/apic.h>
#include <asm/syscalls.h>
#include <linux/uaccess.h>
#include <asm/mwait.h>
#include <asm/fpu/internal.h>
#include <asm/debugreg.h>
#include <asm/nmi.h>
#include <asm/tlbflush.h>
#include <asm/mce.h>
#include <asm/vm86.h>
#include <asm/switch_to.h>
#include <asm/desc.h>
#include <asm/prctl.h>
#include <asm/spec-ctrl.h>
#include <asm/io_bitmap.h>
#include <asm/proto.h>
#include "process.h"
/*
* per-CPU TSS segments. Threads are completely 'soft' on Linux,
* no more per-task TSS's. The TSS size is kept cacheline-aligned
* so they are allowed to end up in the .data..cacheline_aligned
* section. Since TSS's are completely CPU-local, we want them
* on exact cacheline boundaries, to eliminate cacheline ping-pong.
*/
__visible DEFINE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw) = {
.x86_tss = {
/*
* .sp0 is only used when entering ring 0 from a lower
* privilege level. Since the init task never runs anything
* but ring 0 code, there is no need for a valid value here.
* Poison it.
*/
.sp0 = (1UL << (BITS_PER_LONG-1)) + 1,
/*
* .sp1 is cpu_current_top_of_stack. The init task never
* runs user code, but cpu_current_top_of_stack should still
* be well defined before the first context switch.
*/
.sp1 = TOP_OF_INIT_STACK,
#ifdef CONFIG_X86_32
.ss0 = __KERNEL_DS,
.ss1 = __KERNEL_CS,
#endif
.io_bitmap_base = IO_BITMAP_OFFSET_INVALID,
},
};
EXPORT_PER_CPU_SYMBOL(cpu_tss_rw);
DEFINE_PER_CPU(bool, __tss_limit_invalid);
EXPORT_PER_CPU_SYMBOL_GPL(__tss_limit_invalid);
/*
* this gets called so that we can store lazy state into memory and copy the
* current task into the new thread.
*/
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
memcpy(dst, src, arch_task_struct_size);
#ifdef CONFIG_VM86
dst->thread.vm86 = NULL;
#endif
return fpu__copy(dst, src);
}
/*
* Free current thread data structures etc..
*/
void exit_thread(struct task_struct *tsk)
{
struct thread_struct *t = &tsk->thread;
struct fpu *fpu = &t->fpu;
if (test_thread_flag(TIF_IO_BITMAP))
io_bitmap_exit();
free_vm86(t);
fpu__drop(fpu);
}
static int set_new_tls(struct task_struct *p, unsigned long tls)
{
struct user_desc __user *utls = (struct user_desc __user *)tls;
if (in_ia32_syscall())
return do_set_thread_area(p, -1, utls, 0);
else
return do_set_thread_area_64(p, ARCH_SET_FS, tls);
}
int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
unsigned long arg, struct task_struct *p, unsigned long tls)
{
struct inactive_task_frame *frame;
struct fork_frame *fork_frame;
struct pt_regs *childregs;
int ret = 0;
childregs = task_pt_regs(p);
fork_frame = container_of(childregs, struct fork_frame, regs);
frame = &fork_frame->frame;
frame->bp = 0;
frame->ret_addr = (unsigned long) ret_from_fork;
p->thread.sp = (unsigned long) fork_frame;
p->thread.io_bitmap = NULL;
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
#ifdef CONFIG_X86_64
savesegment(gs, p->thread.gsindex);
p->thread.gsbase = p->thread.gsindex ? 0 : current->thread.gsbase;
savesegment(fs, p->thread.fsindex);
p->thread.fsbase = p->thread.fsindex ? 0 : current->thread.fsbase;
savesegment(es, p->thread.es);
savesegment(ds, p->thread.ds);
#else
p->thread.sp0 = (unsigned long) (childregs + 1);
/*
* Clear all status flags including IF and set fixed bit. 64bit
* does not have this initialization as the frame does not contain
* flags. The flags consistency (especially vs. AC) is there
* ensured via objtool, which lacks 32bit support.
*/
frame->flags = X86_EFLAGS_FIXED;
#endif
/* Kernel thread ? */
if (unlikely(p->flags