mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
227 lines
6.2 KiB
227 lines
6.2 KiB
/* |
|
* Copyright (C) 1995 Linus Torvalds |
|
* |
|
* Pentium III FXSR, SSE support |
|
* Gareth Hughes <[email protected]>, May 2000 |
|
*/ |
|
|
|
/* |
|
* This file handles the architecture-dependent parts of process handling.. |
|
*/ |
|
|
|
#include <linux/cpu.h> |
|
#include <linux/errno.h> |
|
#include <linux/sched.h> |
|
#include <linux/sched/task.h> |
|
#include <linux/sched/task_stack.h> |
|
#include <linux/fs.h> |
|
#include <linux/kernel.h> |
|
#include <linux/mm.h> |
|
#include <linux/elfcore.h> |
|
#include <linux/smp.h> |
|
#include <linux/stddef.h> |
|
#include <linux/slab.h> |
|
#include <linux/vmalloc.h> |
|
#include <linux/user.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/delay.h> |
|
#include <linux/reboot.h> |
|
#include <linux/mc146818rtc.h> |
|
#include <linux/export.h> |
|
#include <linux/kallsyms.h> |
|
#include <linux/ptrace.h> |
|
#include <linux/personality.h> |
|
#include <linux/percpu.h> |
|
#include <linux/prctl.h> |
|
#include <linux/ftrace.h> |
|
#include <linux/uaccess.h> |
|
#include <linux/io.h> |
|
#include <linux/kdebug.h> |
|
#include <linux/syscalls.h> |
|
|
|
#include <asm/ldt.h> |
|
#include <asm/processor.h> |
|
#include <asm/fpu/internal.h> |
|
#include <asm/desc.h> |
|
|
|
#include <linux/err.h> |
|
|
|
#include <asm/tlbflush.h> |
|
#include <asm/cpu.h> |
|
#include <asm/debugreg.h> |
|
#include <asm/switch_to.h> |
|
#include <asm/vm86.h> |
|
#include <asm/resctrl.h> |
|
#include <asm/proto.h> |
|
|
|
#include "process.h" |
|
|
|
void __show_regs(struct pt_regs *regs, enum show_regs_mode mode, |
|
const char *log_lvl) |
|
{ |
|
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L; |
|
unsigned long d0, d1, d2, d3, d6, d7; |
|
unsigned short gs; |
|
|
|
if (user_mode(regs)) |
|
gs = get_user_gs(regs); |
|
else |
|
savesegment(gs, gs); |
|
|
|
show_ip(regs, log_lvl); |
|
|
|
printk("%sEAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n", |
|
log_lvl, regs->ax, regs->bx, regs->cx, regs->dx); |
|
printk("%sESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n", |
|
log_lvl, regs->si, regs->di, regs->bp, regs->sp); |
|
printk("%sDS: %04x ES: %04x FS: %04x GS: %04x SS: %04x EFLAGS: %08lx\n", |
|
log_lvl, (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, regs->ss, regs->flags); |
|
|
|
if (mode != SHOW_REGS_ALL) |
|
return; |
|
|
|
cr0 = read_cr0(); |
|
cr2 = read_cr2(); |
|
cr3 = __read_cr3(); |
|
cr4 = __read_cr4(); |
|
printk("%sCR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", |
|
log_lvl, cr0, cr2, cr3, cr4); |
|
|
|
get_debugreg(d0, 0); |
|
get_debugreg(d1, 1); |
|
get_debugreg(d2, 2); |
|
get_debugreg(d3, 3); |
|
get_debugreg(d6, 6); |
|
get_debugreg(d7, 7); |
|
|
|
/* Only print out debug registers if they are in their non-default state. */ |
|
if ((d0 == 0) && (d1 == 0) && (d2 == 0) && (d3 == 0) && |
|
(d6 == DR6_RESERVED) && (d7 == 0x400)) |
|
return; |
|
|
|
printk("%sDR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n", |
|
log_lvl, d0, d1, d2, d3); |
|
printk("%sDR6: %08lx DR7: %08lx\n", |
|
log_lvl, d6, d7); |
|
} |
|
|
|
void release_thread(struct task_struct *dead_task) |
|
{ |
|
BUG_ON(dead_task->mm); |
|
release_vm86_irqs(dead_task); |
|
} |
|
|
|
void |
|
start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) |
|
{ |
|
set_user_gs(regs, 0); |
|
regs->fs = 0; |
|
regs->ds = __USER_DS; |
|
regs->es = __USER_DS; |
|
regs->ss = __USER_DS; |
|
regs->cs = __USER_CS; |
|
regs->ip = new_ip; |
|
regs->sp = new_sp; |
|
regs->flags = X86_EFLAGS_IF; |
|
} |
|
EXPORT_SYMBOL_GPL(start_thread); |
|
|
|
|
|
/* |
|
* switch_to(x,y) should switch tasks from x to y. |
|
* |
|
* We fsave/fwait so that an exception goes off at the right time |
|
* (as a call from the fsave or fwait in effect) rather than to |
|
* the wrong process. Lazy FP saving no longer makes any sense |
|
* with modern CPU's, and this simplifies a lot of things (SMP |
|
* and UP become the same). |
|
* |
|
* NOTE! We used to use the x86 hardware context switching. The |
|
* reason for not using it any more becomes apparent when you |
|
* try to recover gracefully from saved state that is no longer |
|
* valid (stale segment register values in particular). With the |
|
* hardware task-switch, there is no way to fix up bad state in |
|
* a reasonable manner. |
|
* |
|
* The fact that Intel documents the hardware task-switching to |
|
* be slow is a fairly red herring - this code is not noticeably |
|
* faster. However, there _is_ some room for improvement here, |
|
* so the performance issues may eventually be a valid point. |
|
* More important, however, is the fact that this allows us much |
|
* more flexibility. |
|
* |
|
* The return value (in %ax) will be the "prev" task after |
|
* the task-switch, and shows up in ret_from_fork in entry.S, |
|
* for example. |
|
*/ |
|
__visible __notrace_funcgraph struct task_struct * |
|
__switch_to(struct task_struct *prev_p, struct task_struct *next_p) |
|
{ |
|
struct thread_struct *prev = &prev_p->thread, |
|
*next = &next_p->thread; |
|
struct fpu *prev_fpu = &prev->fpu; |
|
struct fpu *next_fpu = &next->fpu; |
|
int cpu = smp_processor_id(); |
|
|
|
/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */ |
|
|
|
if (!test_thread_flag(TIF_NEED_FPU_LOAD)) |
|
switch_fpu_prepare(prev_fpu, cpu); |
|
|
|
/* |
|
* Save away %gs. No need to save %fs, as it was saved on the |
|
* stack on entry. No need to save %es and %ds, as those are |
|
* always kernel segments while inside the kernel. Doing this |
|
* before setting the new TLS descriptors avoids the situation |
|
* where we temporarily have non-reloadable segments in %fs |
|
* and %gs. This could be an issue if the NMI handler ever |
|
* used %fs or %gs (it does not today), or if the kernel is |
|
* running inside of a hypervisor layer. |
|
*/ |
|
lazy_save_gs(prev->gs); |
|
|
|
/* |
|
* Load the per-thread Thread-Local Storage descriptor. |
|
*/ |
|
load_TLS(next, cpu); |
|
|
|
switch_to_extra(prev_p, next_p); |
|
|
|
/* |
|
* Leave lazy mode, flushing any hypercalls made here. |
|
* This must be done before restoring TLS segments so |
|
* the GDT and LDT are properly updated. |
|
*/ |
|
arch_end_context_switch(next_p); |
|
|
|
/* |
|
* Reload esp0 and cpu_current_top_of_stack. This changes |
|
* current_thread_info(). Refresh the SYSENTER configuration in |
|
* case prev or next is vm86. |
|
*/ |
|
update_task_stack(next_p); |
|
refresh_sysenter_cs(next); |
|
this_cpu_write(cpu_current_top_of_stack, |
|
(unsigned long)task_stack_page(next_p) + |
|
THREAD_SIZE); |
|
|
|
/* |
|
* Restore %gs if needed (which is common) |
|
*/ |
|
if (prev->gs | next->gs) |
|
lazy_load_gs(next->gs); |
|
|
|
this_cpu_write(current_task, next_p); |
|
|
|
switch_fpu_finish(next_fpu); |
|
|
|
/* Load the Intel cache allocation PQR MSR. */ |
|
resctrl_sched_in(); |
|
|
|
return prev_p; |
|
} |
|
|
|
SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2) |
|
{ |
|
return do_arch_prctl_common(current, option, arg2); |
|
}
|
|
|