Release 4.9 arch/x86/kernel/process_32.c
/*
* Copyright (C) 1995 Linus Torvalds
*
* Pentium III FXSR, SSE support
* Gareth Hughes <gareth@valinux.com>, 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/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 <asm/pgtable.h>
#include <asm/ldt.h>
#include <asm/processor.h>
#include <asm/fpu/internal.h>
#include <asm/desc.h>
#ifdef CONFIG_MATH_EMULATION
#include <asm/math_emu.h>
#endif
#include <linux/err.h>
#include <asm/tlbflush.h>
#include <asm/cpu.h>
#include <asm/idle.h>
#include <asm/syscalls.h>
#include <asm/debugreg.h>
#include <asm/switch_to.h>
#include <asm/vm86.h>
void __show_regs(struct pt_regs *regs, int all)
{
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
unsigned long d0, d1, d2, d3, d6, d7;
unsigned long sp;
unsigned short ss, gs;
if (user_mode(regs)) {
sp = regs->sp;
ss = regs->ss & 0xffff;
gs = get_user_gs(regs);
} else {
sp = kernel_stack_pointer(regs);
savesegment(ss, ss);
savesegment(gs, gs);
}
printk(KERN_DEFAULT "EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
(u16)regs->cs, regs->ip, regs->flags,
smp_processor_id());
print_symbol("EIP is at %s\n", regs->ip);
printk(KERN_DEFAULT "EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
regs->ax, regs->bx, regs->cx, regs->dx);
printk(KERN_DEFAULT "ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
regs->si, regs->di, regs->bp, sp);
printk(KERN_DEFAULT " DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",
(u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss);
if (!all)
return;
cr0 = read_cr0();
cr2 = read_cr2();
cr3 = read_cr3();
cr4 = __read_cr4();
printk(KERN_DEFAULT "CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n",
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(KERN_DEFAULT "DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
d0, d1, d2, d3);
printk(KERN_DEFAULT "DR6: %08lx DR7: %08lx\n",
d6, d7);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| pre-git | pre-git | 84 | 23.27% | 3 | 15.79% |
| pavel emelianov | pavel emelianov | 81 | 22.44% | 1 | 5.26% |
| alan stern | alan stern | 65 | 18.01% | 1 | 5.26% |
| dave jones | dave jones | 54 | 14.96% | 1 | 5.26% |
| h. peter anvin | h. peter anvin | 21 | 5.82% | 2 | 10.53% |
| zachary amsden | zachary amsden | 19 | 5.26% | 1 | 5.26% |
| harvey harrison | harvey harrison | 12 | 3.32% | 1 | 5.26% |
| pekka j enberg | pekka j enberg | 7 | 1.94% | 2 | 10.53% |
| linus torvalds | linus torvalds | 4 | 1.11% | 1 | 5.26% |
| tejun heo | tejun heo | 4 | 1.11% | 1 | 5.26% |
| ingo molnar | ingo molnar | 4 | 1.11% | 1 | 5.26% |
| jeremy fitzhardinge | jeremy fitzhardinge | 2 | 0.55% | 1 | 5.26% |
| vincent hanquez | vincent hanquez | 2 | 0.55% | 1 | 5.26% |
| andy lutomirski | andy lutomirski | 2 | 0.55% | 2 | 10.53% |
| Total | 361 | 100.00% | 19 | 100.00% |
void release_thread(struct task_struct *dead_task)
{
BUG_ON(dead_task->mm);
release_vm86_irqs(dead_task);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| pre-git | pre-git | 13 | 59.09% | 4 | 50.00% |
| william lee irwin iii | william lee irwin iii | 4 | 18.18% | 1 | 12.50% |
| dave jones | dave jones | 3 | 13.64% | 1 | 12.50% |
| ingo molnar | ingo molnar | 1 | 4.55% | 1 | 12.50% |
| zachary amsden | zachary amsden | 1 | 4.55% | 1 | 12.50% |
| Total | 22 | 100.00% | 8 | 100.00% |
int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
unsigned long arg, struct task_struct *p, unsigned long tls)
{
struct pt_regs *childregs = task_pt_regs(p);
struct fork_frame *fork_frame = container_of(childregs, struct fork_frame, regs);
struct inactive_task_frame *frame = &fork_frame->frame;
struct task_struct *tsk;
int err;
frame->bp = 0;
frame->ret_addr = (unsigned long) ret_from_fork;
p->thread.sp = (unsigned long) fork_frame;
p->thread.sp0 = (unsigned long) (childregs+1);
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
memset(childregs, 0, sizeof(struct pt_regs));
frame->bx = sp; /* function */
frame->di = arg;
p->thread.io_bitmap_ptr = NULL;
return 0;
}
frame->bx = 0;
*childregs = *current_pt_regs();
childregs->ax = 0;
if (sp)
childregs->sp = sp;
task_user_gs(p) = get_user_gs(current_pt_regs());
p->thread.io_bitmap_ptr = NULL;
tsk = current;
err = -ENOMEM;
if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr,
IO_BITMAP_BYTES, GFP_KERNEL);
if (!p->thread.io_bitmap_ptr) {
p->thread.io_bitmap_max = 0;
return -ENOMEM;
}
set_tsk_thread_flag(p, TIF_IO_BITMAP);
}
err = 0;
/*
* Set a new TLS for the child thread?
*/
if (clone_flags & CLONE_SETTLS)
err = do_set_thread_area(p, -1,
(struct user_desc __user *)tls, 0);
if (err && p->thread.io_bitmap_ptr) {
kfree(p->thread.io_bitmap_ptr);
p->thread.io_bitmap_max = 0;
}
return err;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| al viro | al viro | 97 | 26.43% | 2 | 8.00% |
| ingo molnar | ingo molnar | 65 | 17.71% | 3 | 12.00% |
| brian gerst | brian gerst | 51 | 13.90% | 2 | 8.00% |
| pre-git | pre-git | 36 | 9.81% | 5 | 20.00% |
| andrew morton | andrew morton | 25 | 6.81% | 1 | 4.00% |
| oleg nesterov | oleg nesterov | 20 | 5.45% | 1 | 4.00% |
| roland mcgrath | roland mcgrath | 12 | 3.27% | 1 | 4.00% |
| stephane eranian | stephane eranian | 12 | 3.27% | 1 | 4.00% |
| k.prasad | k.prasad | 11 | 3.00% | 1 | 4.00% |
| benjamin lahaise | benjamin lahaise | 9 | 2.45% | 1 | 4.00% |
| alexey dobriyan | alexey dobriyan | 7 | 1.91% | 1 | 4.00% |
| josh triplett | josh triplett | 6 | 1.63% | 1 | 4.00% |
| tejun heo | tejun heo | 5 | 1.36% | 1 | 4.00% |
| vineet gupta | vineet gupta | 4 | 1.09% | 1 | 4.00% |
| albert cahalan | albert cahalan | 4 | 1.09% | 1 | 4.00% |
| h. peter anvin | h. peter anvin | 2 | 0.54% | 1 | 4.00% |
| linus torvalds | linus torvalds | 1 | 0.27% | 1 | 4.00% |
| Total | 367 | 100.00% | 25 | 100.00% |
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;
force_iret();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| ingo molnar | ingo molnar | 60 | 78.95% | 1 | 20.00% |
| al viro | al viro | 7 | 9.21% | 2 | 40.00% |
| tejun heo | tejun heo | 7 | 9.21% | 1 | 20.00% |
| brian gerst | brian gerst | 2 | 2.63% | 1 | 20.00% |
| Total | 76 | 100.00% | 5 | 100.00% |
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();
struct tss_struct *tss = &per_cpu(cpu_tss, cpu);
fpu_switch_t fpu_switch;
/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
fpu_switch = switch_fpu_prepare(prev_fpu, next_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);
/*
* Restore IOPL if needed. In normal use, the flags restore
* in the switch assembly will handle this. But if the kernel
* is running virtualized at a non-zero CPL, the popf will
* not restore flags, so it must be done in a separate step.
*/
if (get_kernel_rpl() && unlikely(prev->iopl != next->iopl))
set_iopl_mask(next->iopl);
/*
* Now maybe handle debug registers and/or IO bitmaps
*/
if (unlikely(task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV ||
task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
__switch_to_xtra(prev_p, next_p, tss);
/*
* Leave lazy mode, flushing any hypercalls made here.
* This must be done before restoring TLS segments so
* the GDT and LDT are properly updated, and must be
* done before fpu__restore(), so the TS bit is up
* to date.
*/
arch_end_context_switch(next_p);
/*
* Reload esp0 and cpu_current_top_of_stack. This changes
* current_thread_info().
*/
load_sp0(tss, 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);
switch_fpu_finish(next_fpu, fpu_switch);
this_cpu_write(current_task, next_p);
return prev_p;
}
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| pre-git | pre-git | 206 | 17.49% | 25 | 21.01% |
| ingo molnar | ingo molnar | 170 | 14.43% | 12 | 10.08% |
| al viro | al viro | 104 | 8.83% | 4 | 3.36% |
| pavel emelianov | pavel emelianov | 81 | 6.88% | 1 | 0.84% |
| zachary amsden | zachary amsden | 71 | 6.03% | 5 | 4.20% |
| alan stern | alan stern | 65 | 5.52% | 1 | 0.84% |
| dave jones | dave jones | 62 | 5.26% | 4 | 3.36% |
| brian gerst | brian gerst | 56 | 4.75% | 4 | 3.36% |
| jeremy fitzhardinge | jeremy fitzhardinge | 35 | 2.97% | 6 | 5.04% |
| andi kleen | andi kleen | 28 | 2.38% | 2 | 1.68% |
| andy lutomirski | andy lutomirski | 26 | 2.21% | 5 | 4.20% |
| linus torvalds | linus torvalds | 25 | 2.12% | 8 | 6.72% |
| andrew morton | andrew morton | 25 | 2.12% | 1 | 0.84% |
| oleg nesterov | oleg nesterov | 25 | 2.12% | 2 | 1.68% |
| h. peter anvin | h. peter anvin | 23 | 1.95% | 2 | 1.68% |
| tejun heo | tejun heo | 18 | 1.53% | 2 | 1.68% |
| stephane eranian | stephane eranian | 18 | 1.53% | 1 | 0.84% |
| andrea arcangeli | andrea arcangeli | 17 | 1.44% | 2 | 1.68% |
| harvey harrison | harvey harrison | 12 | 1.02% | 1 | 0.84% |
| k.prasad | k.prasad | 12 | 1.02% | 1 | 0.84% |
| roland mcgrath | roland mcgrath | 12 | 1.02% | 1 | 0.84% |
| jaswinder singh rajput | jaswinder singh rajput | 9 | 0.76% | 3 | 2.52% |
| benjamin lahaise | benjamin lahaise | 9 | 0.76% | 1 | 0.84% |
| zwane mwaikambo | zwane mwaikambo | 9 | 0.76% | 1 | 0.84% |
| pekka j enberg | pekka j enberg | 7 | 0.59% | 2 | 1.68% |
| alexey dobriyan | alexey dobriyan | 7 | 0.59% | 1 | 0.84% |
| josh triplett | josh triplett | 6 | 0.51% | 1 | 0.84% |
| albert cahalan | albert cahalan | 4 | 0.34% | 1 | 0.84% |
| william lee irwin iii | william lee irwin iii | 4 | 0.34% | 1 | 0.84% |
| vineet gupta | vineet gupta | 4 | 0.34% | 1 | 0.84% |
| daniel jacobowitz | daniel jacobowitz | 3 | 0.25% | 1 | 0.84% |
| erik bosman | erik bosman | 3 | 0.25% | 1 | 0.84% |
| rusty russell | rusty russell | 3 | 0.25% | 1 | 0.84% |
| frederic weisbecker | frederic weisbecker | 3 | 0.25% | 1 | 0.84% |
| vincent hanquez | vincent hanquez | 3 | 0.25% | 2 | 1.68% |
| david howells | david howells | 2 | 0.17% | 2 | 1.68% |
| don zickus | don zickus | 2 | 0.17% | 1 | 0.84% |
| thomas gleixner | thomas gleixner | 2 | 0.17% | 1 | 0.84% |
| kamalesh babulal | kamalesh babulal | 1 | 0.08% | 1 | 0.84% |
| shai fultheim | shai fultheim | 1 | 0.08% | 1 | 0.84% |
| chuck ebbert | chuck ebbert | 1 | 0.08% | 1 | 0.84% |
| paul gortmaker | paul gortmaker | 1 | 0.08% | 1 | 0.84% |
| marc dionne | marc dionne | 1 | 0.08% | 1 | 0.84% |
| alex shi | alex shi | 1 | 0.08% | 1 | 0.84% |
| denys vlasenko | denys vlasenko | 1 | 0.08% | 1 | 0.84% |
| Total | 1178 | 100.00% | 119 | 100.00% |