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/Kconfig | 2 + arch/ia64/include/asm/processor.h | 16 ----- arch/ia64/kernel/entry.S | 29 ++++++--- arch/ia64/kernel/head.S | 13 ---- arch/ia64/kernel/process.c | 129 +++++++++++++++++--------------------- 5 files changed, 82 insertions(+), 107 deletions(-) (limited to 'arch') diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 3279646120e3..670600468128 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -42,6 +42,8 @@ config IA64 select GENERIC_TIME_VSYSCALL_OLD select HAVE_MOD_ARCH_SPECIFIC select MODULES_USE_ELF_RELA + select GENERIC_KERNEL_THREAD + select GENERIC_KERNEL_EXECVE default y help The Itanium Processor Family is Intel's 64-bit successor to diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h index 944152a50912..e0a899a1a8a6 100644 --- a/arch/ia64/include/asm/processor.h +++ b/arch/ia64/include/asm/processor.h @@ -340,22 +340,6 @@ struct task_struct; */ #define release_thread(dead_task) -/* - * This is the mechanism for creating a new kernel thread. - * - * NOTE 1: 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 free'd until both the parent and - * the child have exited. - * - * NOTE 2: This MUST NOT be an inlined function. Otherwise, we get - * into trouble in init/main.c when the child thread returns to - * do_basic_setup() and the timing is such that free_initmem() has - * been called already. - */ -extern pid_t kernel_thread (int (*fn)(void *), void *arg, unsigned long flags); - /* Get wait channel for task P. */ extern unsigned long get_wchan (struct task_struct *p); diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S index 6b0648d97b4c..0dea684e1905 100644 --- a/arch/ia64/kernel/entry.S +++ b/arch/ia64/kernel/entry.S @@ -484,13 +484,6 @@ GLOBAL_ENTRY(prefetch_stack) br.ret.sptk.many rp END(prefetch_stack) -GLOBAL_ENTRY(kernel_execve) - rum psr.ac - mov r15=__NR_execve // put syscall number in place - break __BREAK_SYSCALL - br.ret.sptk.many rp -END(kernel_execve) - /* * Invoke a system call, but do some tracing before and after the call. * We MUST preserve the current register frame throughout this routine @@ -594,6 +587,27 @@ GLOBAL_ENTRY(ia64_strace_leave_kernel) .ret4: br.cond.sptk ia64_leave_kernel END(ia64_strace_leave_kernel) +ENTRY(call_payload) + .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(0) + /* call the kernel_thread payload; fn is in r4, arg - in r5 */ + alloc loc1=ar.pfs,0,3,1,0 + mov loc0=rp + mov loc2=gp + mov out0=r5 // arg + ld8 r14 = [r4], 8 // fn.address + ;; + mov b6 = r14 + ld8 gp = [r4] // fn.gp + ;; + br.call.sptk.many rp=b6 // fn(arg) +.ret12: mov gp=loc2 + mov rp=loc0 + mov ar.pfs=loc1 + /* ... and if it has returned, we are going to userland */ + cmp.ne pKStk,pUStk=r0,r0 + br.ret.sptk.many rp +END(call_payload) + GLOBAL_ENTRY(ia64_ret_from_clone) PT_REGS_UNWIND_INFO(0) { /* @@ -610,6 +624,7 @@ GLOBAL_ENTRY(ia64_ret_from_clone) br.call.sptk.many rp=ia64_invoke_schedule_tail } .ret8: +(pKStk) br.call.sptk.many rp=call_payload adds r2=TI_FLAGS+IA64_TASK_SIZE,r13 ;; ld4 r2=[r2] diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S index 629a250f7c19..4738ff7bd66a 100644 --- a/arch/ia64/kernel/head.S +++ b/arch/ia64/kernel/head.S @@ -1093,19 +1093,6 @@ GLOBAL_ENTRY(cycle_to_cputime) END(cycle_to_cputime) #endif /* CONFIG_VIRT_CPU_ACCOUNTING */ -GLOBAL_ENTRY(start_kernel_thread) - .prologue - .save rp, r0 // this is the end of the call-chain - .body - alloc r2 = ar.pfs, 0, 0, 2, 0 - mov out0 = r9 - mov out1 = r11;; - br.call.sptk.many rp = kernel_thread_helper;; - mov out0 = r8 - br.call.sptk.many rp = sys_exit;; -1: br.sptk.few 1b // not reached -END(start_kernel_thread) - #ifdef CONFIG_IA64_BRL_EMU /* 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 v1.2.3-58-ga151