From 54d496c3915a10b5e46c5dd9de1a6d301ceb32bd Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 14 Oct 2012 15:43:06 -0400 Subject: ia64: switch to generic kernel_thread()/kernel_execve() Acked-by: Tony Luck Tested-by: Tony Luck Signed-off-by: Al Viro --- arch/ia64/kernel/process.c | 129 ++++++++++++++++++++------------------------- 1 file changed, 58 insertions(+), 71 deletions(-) (limited to 'arch/ia64/kernel/process.c') diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 6a48775d9363..37686dbfd264 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -401,55 +401,15 @@ copy_thread(unsigned long clone_flags, 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 @@ copy_thread(unsigned long clone_flags, # 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 @@ out: 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(). */ -- cgit