kernel-fxtec-pro1x/arch/cris/arch-v10/kernel/process.c
Jeff Layton 91a27b2a75 vfs: define struct filename and have getname() return it
getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.

For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.

This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.

Later, we'll add other information to the struct as it becomes
convenient.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12 20:14:55 -04:00

272 lines
7.5 KiB
C

/*
* linux/arch/cris/kernel/process.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 2000-2002 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
* Mikael Starvik (starvik@axis.com)
*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <arch/svinto.h>
#include <linux/init.h>
#include <arch/system.h>
#ifdef CONFIG_ETRAX_GPIO
void etrax_gpio_wake_up_check(void); /* drivers/gpio.c */
#endif
/*
* We use this if we don't have any better
* idle routine..
*/
void default_idle(void)
{
#ifdef CONFIG_ETRAX_GPIO
etrax_gpio_wake_up_check();
#endif
}
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
/* Nothing needs to be done. */
}
/* if the watchdog is enabled, we can simply disable interrupts and go
* into an eternal loop, and the watchdog will reset the CPU after 0.1s
* if on the other hand the watchdog wasn't enabled, we just enable it and wait
*/
void hard_reset_now (void)
{
/*
* Don't declare this variable elsewhere. We don't want any other
* code to know about it than the watchdog handler in entry.S and
* this code, implementing hard reset through the watchdog.
*/
#if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
extern int cause_of_death;
#endif
printk("*** HARD RESET ***\n");
local_irq_disable();
#if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
cause_of_death = 0xbedead;
#else
/* Since we dont plan to keep on resetting the watchdog,
the key can be arbitrary hence three */
*R_WATCHDOG = IO_FIELD(R_WATCHDOG, key, 3) |
IO_STATE(R_WATCHDOG, enable, start);
#endif
while(1) /* waiting for RETRIBUTION! */ ;
}
/*
* Return saved PC of a blocked thread.
*/
unsigned long thread_saved_pc(struct task_struct *t)
{
return task_pt_regs(t)->irp;
}
static void kernel_thread_helper(void* dummy, int (*fn)(void *), void * arg)
{
fn(arg);
do_exit(-1); /* Should never be called, return bad exit value */
}
/*
* Create a kernel thread
*/
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
/* Don't use r10 since that is set to 0 in copy_thread */
regs.r11 = (unsigned long)fn;
regs.r12 = (unsigned long)arg;
regs.irp = (unsigned long)kernel_thread_helper;
regs.dccr = 1 << I_DCCR_BITNR;
/* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
/* setup the child's kernel stack with a pt_regs and switch_stack on it.
* it will be un-nested during _resume and _ret_from_sys_call when the
* new thread is scheduled.
*
* also setup the thread switching structure which is used to keep
* thread-specific data during _resumes.
*
*/
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 pt_regs * childregs;
struct switch_stack *swstack;
/* put the pt_regs structure at the end of the new kernel stack page and fix it up
* remember that the task_struct doubles as the kernel stack for the task
*/
childregs = task_pt_regs(p);
*childregs = *regs; /* struct copy of pt_regs */
p->set_child_tid = p->clear_child_tid = NULL;
childregs->r10 = 0; /* child returns 0 after a fork/clone */
/* put the switch stack right below the pt_regs */
swstack = ((struct switch_stack *)childregs) - 1;
swstack->r9 = 0; /* parameter to ret_from_sys_call, 0 == dont restart the syscall */
/* we want to return into ret_from_sys_call after the _resume */
swstack->return_ip = (unsigned long) ret_from_fork; /* Will call ret_from_sys_call */
/* fix the user-mode stackpointer */
p->thread.usp = usp;
/* and the kernel-mode one */
p->thread.ksp = (unsigned long) swstack;
#ifdef DEBUG
printk("copy_thread: new regs at 0x%p, as shown below:\n", childregs);
show_registers(childregs);
#endif
return 0;
}
/*
* Be aware of the "magic" 7th argument in the four system-calls below.
* They need the latest stackframe, which is put as the 7th argument by
* entry.S. The previous arguments are dummies or actually used, but need
* to be defined to reach the 7th argument.
*
* N.B.: Another method to get the stackframe is to use current_regs(). But
* it returns the latest stack-frame stacked when going from _user mode_ and
* some of these (at least sys_clone) are called from kernel-mode sometimes
* (for example during kernel_thread, above) and thus cannot use it. Thus,
* to be sure not to get any surprises, we use the method for the other calls
* as well.
*/
asmlinkage int sys_fork(long r10, long r11, long r12, long r13, long mof, long srp,
struct pt_regs *regs)
{
return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
}
/* if newusp is 0, we just grab the old usp */
/* FIXME: Is parent_tid/child_tid really third/fourth argument? Update lib? */
asmlinkage int sys_clone(unsigned long newusp, unsigned long flags,
int* parent_tid, int* child_tid, long mof, long srp,
struct pt_regs *regs)
{
if (!newusp)
newusp = rdusp();
return do_fork(flags, newusp, regs, 0, parent_tid, child_tid);
}
/* vfork is a system call in i386 because of register-pressure - maybe
* we can remove it and handle it in libc but we put it here until then.
*/
asmlinkage int sys_vfork(long r10, long r11, long r12, long r13, long mof, long srp,
struct pt_regs *regs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0, NULL, NULL);
}
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(const char *fname,
const char *const *argv,
const char *const *envp,
long r13, long mof, long srp,
struct pt_regs *regs)
{
int error;
struct filename *filename;
filename = getname(fname);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename->name, argv, envp, regs);
putname(filename);
out:
return error;
}
unsigned long get_wchan(struct task_struct *p)
{
#if 0
/* YURGH. TODO. */
unsigned long ebp, esp, eip;
unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)p;
esp = p->thread.esp;
if (!stack_page || esp < stack_page || esp > 8188+stack_page)
return 0;
/* include/asm-i386/system.h:switch_to() pushes ebp last. */
ebp = *(unsigned long *) esp;
do {
if (ebp < stack_page || ebp > 8184+stack_page)
return 0;
eip = *(unsigned long *) (ebp+4);
if (!in_sched_functions(eip))
return eip;
ebp = *(unsigned long *) ebp;
} while (count++ < 16);
#endif
return 0;
}
#undef last_sched
#undef first_sched
void show_regs(struct pt_regs * regs)
{
unsigned long usp = rdusp();
printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n",
regs->irp, regs->srp, regs->dccr, usp, regs->mof );
printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n",
regs->r0, regs->r1, regs->r2, regs->r3);
printk(" r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n",
regs->r4, regs->r5, regs->r6, regs->r7);
printk(" r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n",
regs->r8, regs->r9, regs->r10, regs->r11);
printk("r12: %08lx r13: %08lx oR10: %08lx\n",
regs->r12, regs->r13, regs->orig_r10);
}