From 58254e1002a82eb383c5977ad9fd5a451b91fe29 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 12 Sep 2012 18:32:42 -0400 Subject: [PATCH] powerpc: split ret_from_fork ... and get rid of in-kernel syscalls in kernel_thread() Signed-off-by: Al Viro --- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/processor.h | 3 --- arch/powerpc/kernel/entry_32.S | 11 +++++++++ arch/powerpc/kernel/entry_64.S | 10 ++++++++ arch/powerpc/kernel/misc_32.S | 33 --------------------------- arch/powerpc/kernel/misc_64.S | 34 ---------------------------- arch/powerpc/kernel/ppc_ksyms.c | 1 - arch/powerpc/kernel/process.c | 34 +++++++++++++++++----------- 8 files changed, 43 insertions(+), 84 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 352f416269ce..6e5a0979c085 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -139,6 +139,7 @@ config PPC select GENERIC_CLOCKEVENTS select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER + select GENERIC_KERNEL_THREAD config EARLY_PRINTK bool diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index 54b73a28c205..5376453d90cc 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -74,9 +74,6 @@ struct task_struct; void start_thread(struct pt_regs *regs, unsigned long fdptr, unsigned long sp); void release_thread(struct task_struct *); -/* Create a new kernel thread. */ -extern long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); - /* Lazy FPU handling on uni-processor */ extern struct task_struct *last_task_used_math; extern struct task_struct *last_task_used_altivec; diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index ead5016b02d0..6eb330a87c36 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -435,6 +435,17 @@ ret_from_fork: li r3,0 b ret_from_syscall + .globl ret_from_kernel_thread +ret_from_kernel_thread: + REST_NVGPRS(r1) + bl schedule_tail + mtlr r14 + mr r3,r15 + PPC440EP_ERR42 + blrl + li r3,0 + b do_exit # no return + /* Traced system call support */ syscall_dotrace: SAVE_NVGPRS(r1) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index b40e0b4815b3..d7f4fafc7515 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -370,6 +370,16 @@ _GLOBAL(ret_from_fork) li r3,0 b syscall_exit +_GLOBAL(ret_from_kernel_thread) + bl .schedule_tail + REST_NVGPRS(r1) + REST_GPR(2,r1) + mtlr r14 + mr r3,r15 + blrl + li r3,0 + b .do_exit # no return + .section ".toc","aw" DSCR_DEFAULT: .tc dscr_default[TC],dscr_default diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 407e293aad2f..19e096bd0e73 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -663,39 +663,6 @@ _GLOBAL(abs) sub r3,r3,r4 blr -/* - * Create a kernel thread - * kernel_thread(fn, arg, flags) - */ -_GLOBAL(kernel_thread) - stwu r1,-16(r1) - stw r30,8(r1) - stw r31,12(r1) - mr r30,r3 /* function */ - mr r31,r4 /* argument */ - ori r3,r5,CLONE_VM /* flags */ - oris r3,r3,CLONE_UNTRACED>>16 - li r4,0 /* new sp (unused) */ - li r0,__NR_clone - sc - bns+ 1f /* did system call indicate error? */ - neg r3,r3 /* if so, make return code negative */ -1: cmpwi 0,r3,0 /* parent or child? */ - bne 2f /* return if parent */ - li r0,0 /* make top-level stack frame */ - stwu r0,-16(r1) - mtlr r30 /* fn addr in lr */ - mr r3,r31 /* load arg and call fn */ - PPC440EP_ERR42 - blrl - li r0,__NR_exit /* exit if function returns */ - li r3,0 - sc -2: lwz r30,8(r1) - lwz r31,12(r1) - addi r1,r1,16 - blr - #ifdef CONFIG_SMP _GLOBAL(start_secondary_resume) /* Reset stack */ diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 565b78625a32..5cfa8008693b 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -406,40 +406,6 @@ _GLOBAL(scom970_write) #endif /* CONFIG_CPU_FREQ_PMAC64 || CONFIG_CPU_FREQ_MAPLE */ -/* - * Create a kernel thread - * kernel_thread(fn, arg, flags) - */ -_GLOBAL(kernel_thread) - std r29,-24(r1) - std r30,-16(r1) - stdu r1,-STACK_FRAME_OVERHEAD(r1) - mr r29,r3 - mr r30,r4 - ori r3,r5,CLONE_VM /* flags */ - oris r3,r3,(CLONE_UNTRACED>>16) - li r4,0 /* new sp (unused) */ - li r0,__NR_clone - sc - bns+ 1f /* did system call indicate error? */ - neg r3,r3 /* if so, make return code negative */ -1: cmpdi 0,r3,0 /* parent or child? */ - bne 2f /* return if parent */ - li r0,0 - stdu r0,-STACK_FRAME_OVERHEAD(r1) - ld r2,8(r29) - ld r29,0(r29) - mtlr r29 /* fn addr in lr */ - mr r3,r30 /* load arg and call fn */ - blrl - li r0,__NR_exit /* exit after child exits */ - li r3,0 - sc -2: addi r1,r1,STACK_FRAME_OVERHEAD - ld r29,-24(r1) - ld r30,-16(r1) - blr - /* * disable_kernel_fp() * Disable the FPU. diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c index 3e4031581c65..19e4288d8486 100644 --- a/arch/powerpc/kernel/ppc_ksyms.c +++ b/arch/powerpc/kernel/ppc_ksyms.c @@ -94,7 +94,6 @@ EXPORT_SYMBOL(pci_dram_offset); #endif /* CONFIG_PCI */ EXPORT_SYMBOL(start_thread); -EXPORT_SYMBOL(kernel_thread); EXPORT_SYMBOL(giveup_fpu); #ifdef CONFIG_ALTIVEC diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 1a1f2ddfb581..3b06898fa175 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -734,30 +734,39 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */ int copy_thread(unsigned long clone_flags, unsigned long usp, - unsigned long unused, struct task_struct *p, + unsigned long arg, struct task_struct *p, struct pt_regs *regs) { struct pt_regs *childregs, *kregs; extern void ret_from_fork(void); + extern void ret_from_kernel_thread(void); + void (*f)(void); unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; - CHECK_FULL_REGS(regs); /* Copy registers */ sp -= sizeof(struct pt_regs); childregs = (struct pt_regs *) sp; - *childregs = *regs; - if ((childregs->msr & MSR_PR) == 0) { + if (!regs) { /* for kernel thread, set `current' and stackptr in new task */ + memset(childregs, 0, sizeof(struct pt_regs)); childregs->gpr[1] = sp + sizeof(struct pt_regs); -#ifdef CONFIG_PPC32 - childregs->gpr[2] = (unsigned long) p; -#else +#ifdef CONFIG_PPC64 + childregs->gpr[14] = *(unsigned long *)usp; + childregs->gpr[2] = ((unsigned long *)usp)[1], clear_tsk_thread_flag(p, TIF_32BIT); +#else + childregs->gpr[14] = usp; /* function */ + childregs->gpr[2] = (unsigned long) p; #endif + childregs->gpr[15] = arg; p->thread.regs = NULL; /* no user register state */ + f = ret_from_kernel_thread; } else { + CHECK_FULL_REGS(regs); + *childregs = *regs; childregs->gpr[1] = usp; p->thread.regs = childregs; + childregs->gpr[3] = 0; /* Result from fork() */ if (clone_flags & CLONE_SETTLS) { #ifdef CONFIG_PPC64 if (!is_32bit_task()) @@ -766,8 +775,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, #endif childregs->gpr[2] = childregs->gpr[6]; } + + f = ret_from_fork; } - childregs->gpr[3] = 0; /* Result from fork() */ sp -= STACK_FRAME_OVERHEAD; /* @@ -806,19 +816,17 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, p->thread.dscr = current->thread.dscr; } #endif - /* * The PPC64 ABI makes use of a TOC to contain function * pointers. The function (ret_from_except) is actually a pointer * to the TOC entry. The first entry is a pointer to the actual * function. - */ + */ #ifdef CONFIG_PPC64 - kregs->nip = *((unsigned long *)ret_from_fork); + kregs->nip = *((unsigned long *)f); #else - kregs->nip = (unsigned long)ret_from_fork; + kregs->nip = (unsigned long)f; #endif - return 0; } -- 2.39.5