ia64: switch to generic kernel_thread()/kernel_execve()
Acked-by: Tony Luck <tony.luck@intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 6a48775..37686db 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -401,55 +401,15 @@
struct pt_regs *child_ptregs;
int retval = 0;
- stack = ((struct switch_stack *) regs) - 1;
-
child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
child_stack = (struct switch_stack *) child_ptregs - 1;
- /* copy parent's switch_stack & pt_regs to child: */
- memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
-
rbs = (unsigned long) current + IA64_RBS_OFFSET;
child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
- if (likely(user_mode(child_ptregs))) {
- /* copy the parent's register backing store to the child: */
- rbs_size = stack->ar_bspstore - rbs;
- memcpy((void *) child_rbs, (void *) rbs, rbs_size);
- if (clone_flags & CLONE_SETTLS)
- child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */
- if (user_stack_base) {
- child_ptregs->r12 = user_stack_base + user_stack_size - 16;
- child_ptregs->ar_bspstore = user_stack_base;
- child_ptregs->ar_rnat = 0;
- child_ptregs->loadrs = 0;
- }
- } else {
- /*
- * Note: we simply preserve the relative position of
- * the stack pointer here. There is no need to
- * allocate a scratch area here, since that will have
- * been taken care of by the caller of sys_clone()
- * already.
- */
- rbs_size = 0;
- child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */
- child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */
- }
- child_stack->ar_bspstore = child_rbs + rbs_size;
- child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
-
/* copy parts of thread_struct: */
p->thread.ksp = (unsigned long) child_stack - 16;
- /* stop some PSR bits from being inherited.
- * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
- * therefore we must specify them explicitly here and not include them in
- * IA64_PSR_BITS_TO_CLEAR.
- */
- child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
- & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
-
/*
* NOTE: The calling convention considers all floating point
* registers in the high partition (fph) to be scratch. Since
@@ -471,8 +431,66 @@
# define THREAD_FLAGS_TO_SET 0
p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
| THREAD_FLAGS_TO_SET);
+
ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */
+ if (unlikely(p->flags & PF_KTHREAD)) {
+ if (unlikely(!user_stack_base)) {
+ /* fork_idle() called us */
+ return 0;
+ }
+ memset(child_stack, 0, sizeof(*child_ptregs) + sizeof(*child_stack));
+ child_stack->r4 = user_stack_base; /* payload */
+ child_stack->r5 = user_stack_size; /* argument */
+ /*
+ * Preserve PSR bits, except for bits 32-34 and 37-45,
+ * which we can't read.
+ */
+ child_ptregs->cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
+ /* mark as valid, empty frame */
+ child_ptregs->cr_ifs = 1UL << 63;
+ child_stack->ar_fpsr = child_ptregs->ar_fpsr
+ = ia64_getreg(_IA64_REG_AR_FPSR);
+ child_stack->pr = (1 << PRED_KERNEL_STACK);
+ child_stack->ar_bspstore = child_rbs;
+ child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
+
+ /* stop some PSR bits from being inherited.
+ * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
+ * therefore we must specify them explicitly here and not include them in
+ * IA64_PSR_BITS_TO_CLEAR.
+ */
+ child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
+ & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
+
+ return 0;
+ }
+ stack = ((struct switch_stack *) regs) - 1;
+ /* copy parent's switch_stack & pt_regs to child: */
+ memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
+
+ /* copy the parent's register backing store to the child: */
+ rbs_size = stack->ar_bspstore - rbs;
+ memcpy((void *) child_rbs, (void *) rbs, rbs_size);
+ if (clone_flags & CLONE_SETTLS)
+ child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */
+ if (user_stack_base) {
+ child_ptregs->r12 = user_stack_base + user_stack_size - 16;
+ child_ptregs->ar_bspstore = user_stack_base;
+ child_ptregs->ar_rnat = 0;
+ child_ptregs->loadrs = 0;
+ }
+ child_stack->ar_bspstore = child_rbs + rbs_size;
+ child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
+
+ /* stop some PSR bits from being inherited.
+ * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
+ * therefore we must specify them explicitly here and not include them in
+ * IA64_PSR_BITS_TO_CLEAR.
+ */
+ child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
+ & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
+
#ifdef CONFIG_PERFMON
if (current->thread.pfm_context)
pfm_inherit(p, child_ptregs);
@@ -618,37 +636,6 @@
return error;
}
-pid_t
-kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
-{
- extern void start_kernel_thread (void);
- unsigned long *helper_fptr = (unsigned long *) &start_kernel_thread;
- struct {
- struct switch_stack sw;
- struct pt_regs pt;
- } regs;
-
- memset(®s, 0, sizeof(regs));
- regs.pt.cr_iip = helper_fptr[0]; /* set entry point (IP) */
- regs.pt.r1 = helper_fptr[1]; /* set GP */
- regs.pt.r9 = (unsigned long) fn; /* 1st argument */
- regs.pt.r11 = (unsigned long) arg; /* 2nd argument */
- /* Preserve PSR bits, except for bits 32-34 and 37-45, which we can't read. */
- regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
- regs.pt.cr_ifs = 1UL << 63; /* mark as valid, empty frame */
- regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR);
- regs.sw.pr = (1 << PRED_KERNEL_STACK);
- return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s.pt, 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
-/* This gets called from kernel_thread() via ia64_invoke_thread_helper(). */
-int
-kernel_thread_helper (int (*fn)(void *), void *arg)
-{
- return (*fn)(arg);
-}
-
/*
* Flush thread state. This is called when a thread does an execve().
*/