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linux/arch/sparc/kernel/process_32.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

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/* linux/arch/sparc/kernel/process.c
*
* Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
* Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
*/
/*
* This file handles the architecture-dependent parts of process handling..
*/
#include <stdarg.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <asm/auxio.h>
#include <asm/oplib.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/delay.h>
#include <asm/processor.h>
#include <asm/psr.h>
#include <asm/elf.h>
#include <asm/prom.h>
#include <asm/unistd.h>
#include <asm/setup.h>
/*
* Power management idle function
* Set in pm platform drivers (apc.c and pmc.c)
*/
void (*pm_idle)(void);
EXPORT_SYMBOL(pm_idle);
/*
* Power-off handler instantiation for pm.h compliance
* This is done via auxio, but could be used as a fallback
* handler when auxio is not present-- unused for now...
*/
void (*pm_power_off)(void) = machine_power_off;
EXPORT_SYMBOL(pm_power_off);
/*
* sysctl - toggle power-off restriction for serial console
* systems in machine_power_off()
*/
int scons_pwroff = 1;
extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
struct task_struct *last_task_used_math = NULL;
struct thread_info *current_set[NR_CPUS];
/*
* the idle loop on a Sparc... ;)
*/
void cpu_idle(void)
{
set_thread_flag(TIF_POLLING_NRFLAG);
/* endless idle loop with no priority at all */
for (;;) {
while (!need_resched()) {
if (pm_idle)
(*pm_idle)();
else
cpu_relax();
}
schedule_preempt_disabled();
}
}
/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
void machine_halt(void)
{
local_irq_enable();
mdelay(8);
local_irq_disable();
prom_halt();
panic("Halt failed!");
}
void machine_restart(char * cmd)
{
char *p;
local_irq_enable();
mdelay(8);
local_irq_disable();
p = strchr (reboot_command, '\n');
if (p) *p = 0;
if (cmd)
prom_reboot(cmd);
if (*reboot_command)
prom_reboot(reboot_command);
prom_feval ("reset");
panic("Reboot failed!");
}
void machine_power_off(void)
{
if (auxio_power_register &&
(strcmp(of_console_device->type, "serial") || scons_pwroff))
*auxio_power_register |= AUXIO_POWER_OFF;
machine_halt();
}
void show_regs(struct pt_regs *r)
{
struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
r->psr, r->pc, r->npc, r->y, print_tainted());
printk("PC: <%pS>\n", (void *) r->pc);
printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
}
/*
* The show_stack is an external API which we do not use ourselves.
* The oops is printed in die_if_kernel.
*/
void show_stack(struct task_struct *tsk, unsigned long *_ksp)
{
unsigned long pc, fp;
unsigned long task_base;
struct reg_window32 *rw;
int count = 0;
if (tsk != NULL)
task_base = (unsigned long) task_stack_page(tsk);
else
task_base = (unsigned long) current_thread_info();
fp = (unsigned long) _ksp;
do {
/* Bogus frame pointer? */
if (fp < (task_base + sizeof(struct thread_info)) ||
fp >= (task_base + (PAGE_SIZE << 1)))
break;
rw = (struct reg_window32 *) fp;
pc = rw->ins[7];
printk("[%08lx : ", pc);
printk("%pS ] ", (void *) pc);
fp = rw->ins[6];
} while (++count < 16);
printk("\n");
}
void dump_stack(void)
{
unsigned long *ksp;
__asm__ __volatile__("mov %%fp, %0"
: "=r" (ksp));
show_stack(current, ksp);
}
EXPORT_SYMBOL(dump_stack);
/*
* Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
return task_thread_info(tsk)->kpc;
}
/*
* Free current thread data structures etc..
*/
void exit_thread(void)
{
#ifndef CONFIG_SMP
if(last_task_used_math == current) {
#else
if (test_thread_flag(TIF_USEDFPU)) {
#endif
/* Keep process from leaving FPU in a bogon state. */
put_psr(get_psr() | PSR_EF);
fpsave(&current->thread.float_regs[0], &current->thread.fsr,
&current->thread.fpqueue[0], &current->thread.fpqdepth);
#ifndef CONFIG_SMP
last_task_used_math = NULL;
#else
clear_thread_flag(TIF_USEDFPU);
#endif
}
}
void flush_thread(void)
{
current_thread_info()->w_saved = 0;
#ifndef CONFIG_SMP
if(last_task_used_math == current) {
#else
if (test_thread_flag(TIF_USEDFPU)) {
#endif
/* Clean the fpu. */
put_psr(get_psr() | PSR_EF);
fpsave(&current->thread.float_regs[0], &current->thread.fsr,
&current->thread.fpqueue[0], &current->thread.fpqdepth);
#ifndef CONFIG_SMP
last_task_used_math = NULL;
#else
clear_thread_flag(TIF_USEDFPU);
#endif
}
/* This task is no longer a kernel thread. */
if (current->thread.flags & SPARC_FLAG_KTHREAD) {
current->thread.flags &= ~SPARC_FLAG_KTHREAD;
/* We must fixup kregs as well. */
/* XXX This was not fixed for ti for a while, worked. Unused? */
current->thread.kregs = (struct pt_regs *)
(task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
}
}
static inline struct sparc_stackf __user *
clone_stackframe(struct sparc_stackf __user *dst,
struct sparc_stackf __user *src)
{
unsigned long size, fp;
struct sparc_stackf *tmp;
struct sparc_stackf __user *sp;
if (get_user(tmp, &src->fp))
return NULL;
fp = (unsigned long) tmp;
size = (fp - ((unsigned long) src));
fp = (unsigned long) dst;
sp = (struct sparc_stackf __user *)(fp - size);
/* do_fork() grabs the parent semaphore, we must release it
* temporarily so we can build the child clone stack frame
* without deadlocking.
*/
if (__copy_user(sp, src, size))
sp = NULL;
else if (put_user(fp, &sp->fp))
sp = NULL;
return sp;
}
asmlinkage int sparc_do_fork(unsigned long clone_flags,
unsigned long stack_start,
struct pt_regs *regs,
unsigned long stack_size)
{
unsigned long parent_tid_ptr, child_tid_ptr;
unsigned long orig_i1 = regs->u_regs[UREG_I1];
long ret;
parent_tid_ptr = regs->u_regs[UREG_I2];
child_tid_ptr = regs->u_regs[UREG_I4];
ret = do_fork(clone_flags, stack_start,
regs, stack_size,
(int __user *) parent_tid_ptr,
(int __user *) child_tid_ptr);
/* If we get an error and potentially restart the system
* call, we're screwed because copy_thread() clobbered
* the parent's %o1. So detect that case and restore it
* here.
*/
if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
regs->u_regs[UREG_I1] = orig_i1;
return ret;
}
/* Copy a Sparc thread. The fork() return value conventions
* under SunOS are nothing short of bletcherous:
* Parent --> %o0 == childs pid, %o1 == 0
* Child --> %o0 == parents pid, %o1 == 1
*
* NOTE: We have a separate fork kpsr/kwim because
* the parent could change these values between
* sys_fork invocation and when we reach here
* if the parent should sleep while trying to
* allocate the task_struct and kernel stack in
* do_fork().
* XXX See comment above sys_vfork in sparc64. todo.
*/
extern void ret_from_fork(void);
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
char *new_stack;
#ifndef CONFIG_SMP
if(last_task_used_math == current) {
#else
if (test_thread_flag(TIF_USEDFPU)) {
#endif
put_psr(get_psr() | PSR_EF);
fpsave(&p->thread.float_regs[0], &p->thread.fsr,
&p->thread.fpqueue[0], &p->thread.fpqdepth);
}
/*
* p->thread_info new_stack childregs
* ! ! ! {if(PSR_PS) }
* V V (stk.fr.) V (pt_regs) { (stk.fr.) }
* +----- - - - - - ------+===========+============={+==========}+
*/
new_stack = task_stack_page(p) + THREAD_SIZE;
if (regs->psr & PSR_PS)
new_stack -= STACKFRAME_SZ;
new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
/*
* A new process must start with interrupts closed in 2.5,
* because this is how Mingo's scheduler works (see schedule_tail
* and finish_arch_switch). If we do not do it, a timer interrupt hits
* before we unlock, attempts to re-take the rq->lock, and then we die.
* Thus, kpsr|=PSR_PIL.
*/
ti->ksp = (unsigned long) new_stack;
ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
ti->kwim = current->thread.fork_kwim;
if(regs->psr & PSR_PS) {
extern struct pt_regs fake_swapper_regs;
p->thread.kregs = &fake_swapper_regs;
new_stack += STACKFRAME_SZ + TRACEREG_SZ;
childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
p->thread.flags |= SPARC_FLAG_KTHREAD;
p->thread.current_ds = KERNEL_DS;
memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
childregs->u_regs[UREG_G6] = (unsigned long) ti;
} else {
p->thread.kregs = childregs;
childregs->u_regs[UREG_FP] = sp;
p->thread.flags &= ~SPARC_FLAG_KTHREAD;
p->thread.current_ds = USER_DS;
if (sp != regs->u_regs[UREG_FP]) {
struct sparc_stackf __user *childstack;
struct sparc_stackf __user *parentstack;
/*
* This is a clone() call with supplied user stack.
* Set some valid stack frames to give to the child.
*/
childstack = (struct sparc_stackf __user *)
(sp & ~0xfUL);
parentstack = (struct sparc_stackf __user *)
regs->u_regs[UREG_FP];
#if 0
printk("clone: parent stack:\n");
show_stackframe(parentstack);
#endif
childstack = clone_stackframe(childstack, parentstack);
if (!childstack)
return -EFAULT;
#if 0
printk("clone: child stack:\n");
show_stackframe(childstack);
#endif
childregs->u_regs[UREG_FP] = (unsigned long)childstack;
}
}
#ifdef CONFIG_SMP
/* FPU must be disabled on SMP. */
childregs->psr &= ~PSR_EF;
clear_tsk_thread_flag(p, TIF_USEDFPU);
#endif
/* Set the return value for the child. */
childregs->u_regs[UREG_I0] = current->pid;
childregs->u_regs[UREG_I1] = 1;
/* Set the return value for the parent. */
regs->u_regs[UREG_I1] = 0;
if (clone_flags & CLONE_SETTLS)
childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
return 0;
}
/*
* fill in the fpu structure for a core dump.
*/
int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
{
if (used_math()) {
memset(fpregs, 0, sizeof(*fpregs));
fpregs->pr_q_entrysize = 8;
return 1;
}
#ifdef CONFIG_SMP
if (test_thread_flag(TIF_USEDFPU)) {
put_psr(get_psr() | PSR_EF);
fpsave(&current->thread.float_regs[0], &current->thread.fsr,
&current->thread.fpqueue[0], &current->thread.fpqdepth);
if (regs != NULL) {
regs->psr &= ~(PSR_EF);
clear_thread_flag(TIF_USEDFPU);
}
}
#else
if (current == last_task_used_math) {
put_psr(get_psr() | PSR_EF);
fpsave(&current->thread.float_regs[0], &current->thread.fsr,
&current->thread.fpqueue[0], &current->thread.fpqdepth);
if (regs != NULL) {
regs->psr &= ~(PSR_EF);
last_task_used_math = NULL;
}
}
#endif
memcpy(&fpregs->pr_fr.pr_regs[0],
&current->thread.float_regs[0],
(sizeof(unsigned long) * 32));
fpregs->pr_fsr = current->thread.fsr;
fpregs->pr_qcnt = current->thread.fpqdepth;
fpregs->pr_q_entrysize = 8;
fpregs->pr_en = 1;
if(fpregs->pr_qcnt != 0) {
memcpy(&fpregs->pr_q[0],
&current->thread.fpqueue[0],
sizeof(struct fpq) * fpregs->pr_qcnt);
}
/* Zero out the rest. */
memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
return 1;
}
/*
* sparc_execve() executes a new program after the asm stub has set
* things up for us. This should basically do what I want it to.
*/
asmlinkage int sparc_execve(struct pt_regs *regs)
{
int error, base = 0;
struct filename *filename;
/* Check for indirect call. */
if(regs->u_regs[UREG_G1] == 0)
base = 1;
filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
error = PTR_ERR(filename);
if(IS_ERR(filename))
goto out;
error = do_execve(filename->name,
(const char __user *const __user *)
regs->u_regs[base + UREG_I1],
(const char __user *const __user *)
regs->u_regs[base + UREG_I2],
regs);
putname(filename);
out:
return error;
}
/*
* This is the mechanism for creating a new kernel thread.
*
* NOTE! Only a kernel-only process(ie the swapper or direct descendants
* who haven't done an "execve()") should use this: it will work within
* a system call from a "real" process, but the process memory space will
* not be freed until both the parent and the child have exited.
*/
pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
long retval;
__asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
"mov %5, %%g3\n\t" /* and arg. */
"mov %1, %%g1\n\t"
"mov %2, %%o0\n\t" /* Clone flags. */
"mov 0, %%o1\n\t" /* usp arg == 0 */
"t 0x10\n\t" /* Linux/Sparc clone(). */
"cmp %%o1, 0\n\t"
"be 1f\n\t" /* The parent, just return. */
" nop\n\t" /* Delay slot. */
"jmpl %%g2, %%o7\n\t" /* Call the function. */
" mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
"mov %3, %%g1\n\t"
"t 0x10\n\t" /* Linux/Sparc exit(). */
/* Notreached by child. */
"1: mov %%o0, %0\n\t" :
"=r" (retval) :
"i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
"i" (__NR_exit), "r" (fn), "r" (arg) :
"g1", "g2", "g3", "o0", "o1", "memory", "cc");
return retval;
}
EXPORT_SYMBOL(kernel_thread);
unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc, fp, bias = 0;
unsigned long task_base = (unsigned long) task;
unsigned long ret = 0;
struct reg_window32 *rw;
int count = 0;
if (!task || task == current ||
task->state == TASK_RUNNING)
goto out;
fp = task_thread_info(task)->ksp + bias;
do {
/* Bogus frame pointer? */
if (fp < (task_base + sizeof(struct thread_info)) ||
fp >= (task_base + (2 * PAGE_SIZE)))
break;
rw = (struct reg_window32 *) fp;
pc = rw->ins[7];
if (!in_sched_functions(pc)) {
ret = pc;
goto out;
}
fp = rw->ins[6] + bias;
} while (++count < 16);
out:
return ret;
}
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