ec0d7f18ab
Pull fpu state cleanups from Ingo Molnar: "This tree streamlines further aspects of FPU handling by eliminating the prepare_to_copy() complication and moving that logic to arch_dup_task_struct(). It also fixes the FPU dumps in threaded core dumps, removes and old (and now invalid) assumption plus micro-optimizes the exit path by avoiding an FPU save for dead tasks." Fixed up trivial add-add conflict in arch/sh/kernel/process.c that came in because we now do the FPU handling in arch_dup_task_struct() rather than the legacy (and now gone) prepare_to_copy(). * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, fpu: drop the fpu state during thread exit x86, xsave: remove thread_has_fpu() bug check in __sanitize_i387_state() coredump: ensure the fpu state is flushed for proper multi-threaded core dump fork: move the real prepare_to_copy() users to arch_dup_task_struct()
334 lines
8.1 KiB
C
334 lines
8.1 KiB
C
/*
|
|
* arch/sh/kernel/process.c
|
|
*
|
|
* This file handles the architecture-dependent parts of process handling..
|
|
*
|
|
* Copyright (C) 1995 Linus Torvalds
|
|
*
|
|
* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
|
|
* Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
|
|
* Copyright (C) 2002 - 2008 Paul Mundt
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/elfcore.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/hw_breakpoint.h>
|
|
#include <linux/prefetch.h>
|
|
#include <linux/stackprotector.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/mmu_context.h>
|
|
#include <asm/fpu.h>
|
|
#include <asm/syscalls.h>
|
|
#include <asm/switch_to.h>
|
|
|
|
void show_regs(struct pt_regs * regs)
|
|
{
|
|
printk("\n");
|
|
printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);
|
|
printk("CPU : %d \t\t%s (%s %.*s)\n\n",
|
|
smp_processor_id(), print_tainted(), init_utsname()->release,
|
|
(int)strcspn(init_utsname()->version, " "),
|
|
init_utsname()->version);
|
|
|
|
print_symbol("PC is at %s\n", instruction_pointer(regs));
|
|
print_symbol("PR is at %s\n", regs->pr);
|
|
|
|
printk("PC : %08lx SP : %08lx SR : %08lx ",
|
|
regs->pc, regs->regs[15], regs->sr);
|
|
#ifdef CONFIG_MMU
|
|
printk("TEA : %08x\n", __raw_readl(MMU_TEA));
|
|
#else
|
|
printk("\n");
|
|
#endif
|
|
|
|
printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
|
|
regs->regs[0],regs->regs[1],
|
|
regs->regs[2],regs->regs[3]);
|
|
printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
|
|
regs->regs[4],regs->regs[5],
|
|
regs->regs[6],regs->regs[7]);
|
|
printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
|
|
regs->regs[8],regs->regs[9],
|
|
regs->regs[10],regs->regs[11]);
|
|
printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
|
|
regs->regs[12],regs->regs[13],
|
|
regs->regs[14]);
|
|
printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
|
|
regs->mach, regs->macl, regs->gbr, regs->pr);
|
|
|
|
show_trace(NULL, (unsigned long *)regs->regs[15], regs);
|
|
show_code(regs);
|
|
}
|
|
|
|
/*
|
|
* Create a kernel thread
|
|
*/
|
|
__noreturn void kernel_thread_helper(void *arg, int (*fn)(void *))
|
|
{
|
|
do_exit(fn(arg));
|
|
}
|
|
|
|
/* Don't use this in BL=1(cli). Or else, CPU resets! */
|
|
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
|
|
{
|
|
struct pt_regs regs;
|
|
int pid;
|
|
|
|
memset(®s, 0, sizeof(regs));
|
|
regs.regs[4] = (unsigned long)arg;
|
|
regs.regs[5] = (unsigned long)fn;
|
|
|
|
regs.pc = (unsigned long)kernel_thread_helper;
|
|
regs.sr = SR_MD;
|
|
#if defined(CONFIG_SH_FPU)
|
|
regs.sr |= SR_FD;
|
|
#endif
|
|
|
|
/* Ok, create the new process.. */
|
|
pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
|
|
®s, 0, NULL, NULL);
|
|
|
|
return pid;
|
|
}
|
|
EXPORT_SYMBOL(kernel_thread);
|
|
|
|
void start_thread(struct pt_regs *regs, unsigned long new_pc,
|
|
unsigned long new_sp)
|
|
{
|
|
regs->pr = 0;
|
|
regs->sr = SR_FD;
|
|
regs->pc = new_pc;
|
|
regs->regs[15] = new_sp;
|
|
|
|
free_thread_xstate(current);
|
|
}
|
|
EXPORT_SYMBOL(start_thread);
|
|
|
|
/*
|
|
* Free current thread data structures etc..
|
|
*/
|
|
void exit_thread(void)
|
|
{
|
|
}
|
|
|
|
void flush_thread(void)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
|
|
flush_ptrace_hw_breakpoint(tsk);
|
|
|
|
#if defined(CONFIG_SH_FPU)
|
|
/* Forget lazy FPU state */
|
|
clear_fpu(tsk, task_pt_regs(tsk));
|
|
clear_used_math();
|
|
#endif
|
|
}
|
|
|
|
void release_thread(struct task_struct *dead_task)
|
|
{
|
|
/* do nothing */
|
|
}
|
|
|
|
/* Fill in the fpu structure for a core dump.. */
|
|
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
|
|
{
|
|
int fpvalid = 0;
|
|
|
|
#if defined(CONFIG_SH_FPU)
|
|
struct task_struct *tsk = current;
|
|
|
|
fpvalid = !!tsk_used_math(tsk);
|
|
if (fpvalid)
|
|
fpvalid = !fpregs_get(tsk, NULL, 0,
|
|
sizeof(struct user_fpu_struct),
|
|
fpu, NULL);
|
|
#endif
|
|
|
|
return fpvalid;
|
|
}
|
|
EXPORT_SYMBOL(dump_fpu);
|
|
|
|
asmlinkage void ret_from_fork(void);
|
|
|
|
int copy_thread(unsigned long clone_flags, unsigned long usp,
|
|
unsigned long unused,
|
|
struct task_struct *p, struct pt_regs *regs)
|
|
{
|
|
struct thread_info *ti = task_thread_info(p);
|
|
struct pt_regs *childregs;
|
|
|
|
#if defined(CONFIG_SH_DSP)
|
|
struct task_struct *tsk = current;
|
|
|
|
if (is_dsp_enabled(tsk)) {
|
|
/* We can use the __save_dsp or just copy the struct:
|
|
* __save_dsp(p);
|
|
* p->thread.dsp_status.status |= SR_DSP
|
|
*/
|
|
p->thread.dsp_status = tsk->thread.dsp_status;
|
|
}
|
|
#endif
|
|
|
|
childregs = task_pt_regs(p);
|
|
*childregs = *regs;
|
|
|
|
if (user_mode(regs)) {
|
|
childregs->regs[15] = usp;
|
|
ti->addr_limit = USER_DS;
|
|
} else {
|
|
childregs->regs[15] = (unsigned long)childregs;
|
|
ti->addr_limit = KERNEL_DS;
|
|
ti->status &= ~TS_USEDFPU;
|
|
p->fpu_counter = 0;
|
|
}
|
|
|
|
if (clone_flags & CLONE_SETTLS)
|
|
childregs->gbr = childregs->regs[0];
|
|
|
|
childregs->regs[0] = 0; /* Set return value for child */
|
|
|
|
p->thread.sp = (unsigned long) childregs;
|
|
p->thread.pc = (unsigned long) ret_from_fork;
|
|
|
|
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* switch_to(x,y) should switch tasks from x to y.
|
|
*
|
|
*/
|
|
__notrace_funcgraph struct task_struct *
|
|
__switch_to(struct task_struct *prev, struct task_struct *next)
|
|
{
|
|
struct thread_struct *next_t = &next->thread;
|
|
|
|
#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
|
|
__stack_chk_guard = next->stack_canary;
|
|
#endif
|
|
|
|
unlazy_fpu(prev, task_pt_regs(prev));
|
|
|
|
/* we're going to use this soon, after a few expensive things */
|
|
if (next->fpu_counter > 5)
|
|
prefetch(next_t->xstate);
|
|
|
|
#ifdef CONFIG_MMU
|
|
/*
|
|
* Restore the kernel mode register
|
|
* k7 (r7_bank1)
|
|
*/
|
|
asm volatile("ldc %0, r7_bank"
|
|
: /* no output */
|
|
: "r" (task_thread_info(next)));
|
|
#endif
|
|
|
|
/*
|
|
* If the task has used fpu the last 5 timeslices, just do a full
|
|
* restore of the math state immediately to avoid the trap; the
|
|
* chances of needing FPU soon are obviously high now
|
|
*/
|
|
if (next->fpu_counter > 5)
|
|
__fpu_state_restore();
|
|
|
|
return prev;
|
|
}
|
|
|
|
asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
|
|
unsigned long r6, unsigned long r7,
|
|
struct pt_regs __regs)
|
|
{
|
|
#ifdef CONFIG_MMU
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
|
|
#else
|
|
/* fork almost works, enough to trick you into looking elsewhere :-( */
|
|
return -EINVAL;
|
|
#endif
|
|
}
|
|
|
|
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
|
|
unsigned long parent_tidptr,
|
|
unsigned long child_tidptr,
|
|
struct pt_regs __regs)
|
|
{
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
if (!newsp)
|
|
newsp = regs->regs[15];
|
|
return do_fork(clone_flags, newsp, regs, 0,
|
|
(int __user *)parent_tidptr,
|
|
(int __user *)child_tidptr);
|
|
}
|
|
|
|
/*
|
|
* This is trivial, and on the face of it looks like it
|
|
* could equally well be done in user mode.
|
|
*
|
|
* Not so, for quite unobvious reasons - register pressure.
|
|
* In user mode vfork() cannot have a stack frame, and if
|
|
* done by calling the "clone()" system call directly, you
|
|
* do not have enough call-clobbered registers to hold all
|
|
* the information you need.
|
|
*/
|
|
asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
|
|
unsigned long r6, unsigned long r7,
|
|
struct pt_regs __regs)
|
|
{
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
|
|
0, NULL, NULL);
|
|
}
|
|
|
|
/*
|
|
* sys_execve() executes a new program.
|
|
*/
|
|
asmlinkage int sys_execve(const char __user *ufilename,
|
|
const char __user *const __user *uargv,
|
|
const char __user *const __user *uenvp,
|
|
unsigned long r7, struct pt_regs __regs)
|
|
{
|
|
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
|
|
int error;
|
|
char *filename;
|
|
|
|
filename = getname(ufilename);
|
|
error = PTR_ERR(filename);
|
|
if (IS_ERR(filename))
|
|
goto out;
|
|
|
|
error = do_execve(filename, uargv, uenvp, regs);
|
|
putname(filename);
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
unsigned long get_wchan(struct task_struct *p)
|
|
{
|
|
unsigned long pc;
|
|
|
|
if (!p || p == current || p->state == TASK_RUNNING)
|
|
return 0;
|
|
|
|
/*
|
|
* The same comment as on the Alpha applies here, too ...
|
|
*/
|
|
pc = thread_saved_pc(p);
|
|
|
|
#ifdef CONFIG_FRAME_POINTER
|
|
if (in_sched_functions(pc)) {
|
|
unsigned long schedule_frame = (unsigned long)p->thread.sp;
|
|
return ((unsigned long *)schedule_frame)[21];
|
|
}
|
|
#endif
|
|
|
|
return pc;
|
|
}
|