sparc64: switch to generic kernel_thread()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-10-05 22:37:01 -04:00
parent dff933da76
commit 1918c7f548
5 changed files with 42 additions and 82 deletions

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@ -74,6 +74,7 @@ config SPARC64
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select HAVE_C_RECORDMCOUNT
select NO_BOOTMEM
select GENERIC_KERNEL_THREAD
config ARCH_DEFCONFIG
string

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@ -188,8 +188,6 @@ do { \
/* Free all resources held by a thread. */
#define release_thread(tsk) do { } while (0)
extern pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
extern unsigned long get_wchan(struct task_struct *task);
#define task_pt_regs(tsk) (task_thread_info(tsk)->kregs)

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@ -32,6 +32,9 @@ static inline bool pt_regs_clear_syscall(struct pt_regs *regs)
#define arch_ptrace_stop(exit_code, info) \
synchronize_user_stack()
#define current_pt_regs() \
((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
struct global_reg_snapshot {
unsigned long tstate;
unsigned long tpc;

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@ -538,64 +538,56 @@ asmlinkage long sparc_do_fork(unsigned long clone_flags,
* Child --> %o0 == parents pid, %o1 == 1
*/
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long unused,
unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *t = task_thread_info(p);
struct sparc_stackf *parent_sf;
unsigned long child_stack_sz;
char *child_trap_frame;
int kernel_thread;
kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
parent_sf = ((struct sparc_stackf *) regs) - 1;
/* Calculate offset to stack_frame & pt_regs */
child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
(kernel_thread ? STACKFRAME_SZ : 0));
child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
child_trap_frame = (task_stack_page(p) +
(THREAD_SIZE - child_stack_sz));
memcpy(child_trap_frame, parent_sf, child_stack_sz);
__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
(regs->tstate + 1) & TSTATE_CWP;
t->new_child = 1;
t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
t->kregs = (struct pt_regs *) (child_trap_frame +
sizeof(struct sparc_stackf));
t->fpsaved[0] = 0;
if (kernel_thread) {
struct sparc_stackf *child_sf = (struct sparc_stackf *)
(child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
/* Zero terminate the stack backtrace. */
child_sf->fp = NULL;
t->kregs->u_regs[UREG_FP] =
((unsigned long) child_sf) - STACK_BIAS;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(child_trap_frame, 0, child_stack_sz);
__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
(current_pt_regs()->tstate + 1) & TSTATE_CWP;
t->current_ds = ASI_P;
t->kregs->u_regs[UREG_G6] = (unsigned long) t;
t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
} else {
if (t->flags & _TIF_32BIT) {
sp &= 0x00000000ffffffffUL;
regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
}
t->kregs->u_regs[UREG_FP] = sp;
t->current_ds = ASI_AIUS;
if (sp != regs->u_regs[UREG_FP]) {
unsigned long csp;
csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
if (!csp)
return -EFAULT;
t->kregs->u_regs[UREG_FP] = csp;
}
if (t->utraps)
t->utraps[0]++;
t->kregs->u_regs[UREG_G1] = sp; /* function */
t->kregs->u_regs[UREG_G2] = arg;
return 0;
}
parent_sf = ((struct sparc_stackf *) regs) - 1;
memcpy(child_trap_frame, parent_sf, child_stack_sz);
if (t->flags & _TIF_32BIT) {
sp &= 0x00000000ffffffffUL;
regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
}
t->kregs->u_regs[UREG_FP] = sp;
__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
(regs->tstate + 1) & TSTATE_CWP;
t->current_ds = ASI_AIUS;
if (sp != regs->u_regs[UREG_FP]) {
unsigned long csp;
csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
if (!csp)
return -EFAULT;
t->kregs->u_regs[UREG_FP] = csp;
}
if (t->utraps)
t->utraps[0]++;
/* Set the return value for the child. */
t->kregs->u_regs[UREG_I0] = current->pid;
t->kregs->u_regs[UREG_I1] = 1;
@ -609,45 +601,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
return 0;
}
/*
* 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;
/* If the parent runs before fn(arg) is called by the child,
* the input registers of this function can be clobbered.
* So we stash 'fn' and 'arg' into global registers which
* will not be modified by the parent.
*/
__asm__ __volatile__("mov %4, %%g2\n\t" /* Save FN into global */
"mov %5, %%g3\n\t" /* Save ARG into global */
"mov %1, %%g1\n\t" /* Clone syscall nr. */
"mov %2, %%o0\n\t" /* Clone flags. */
"mov 0, %%o1\n\t" /* usp arg == 0 */
"t 0x6d\n\t" /* Linux/Sparc clone(). */
"brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
" mov %%o0, %0\n\t"
"jmpl %%g2, %%o7\n\t" /* Call the function. */
" mov %%g3, %%o0\n\t" /* Set arg in delay. */
"mov %3, %%g1\n\t"
"t 0x6d\n\t" /* Linux/Sparc exit(). */
/* Notreached by child. */
"1:" :
"=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);
typedef struct {
union {
unsigned int pr_regs[32];

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@ -112,11 +112,16 @@ sys_clone:
ret_from_syscall:
/* Clear current_thread_info()->new_child. */
stb %g0, [%g6 + TI_NEW_CHILD]
ldx [%g6 + TI_FLAGS], %l0
call schedule_tail
mov %g7, %o0
ba,pt %xcc, ret_sys_call
ldx [%sp + PTREGS_OFF + PT_V9_I0], %o0
ldx [%sp + PTREGS_OFF + PT_V9_I0], %o0
brnz,a,pt %o0, ret_sys_call
ldx [%g6 + TI_FLAGS], %l0
ldx [%sp + PTREGS_OFF + PT_V9_G1], %l0
call %l0
ldx [%sp + PTREGS_OFF + PT_V9_G2], %o0
call do_exit ! will not return
mov 0,%o0
.globl sparc_exit
.type sparc_exit,#function