Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757451Ab2JSIpY (ORCPT ); Fri, 19 Oct 2012 04:45:24 -0400 Received: from mprc.pku.edu.cn ([162.105.203.9]:47223 "EHLO mprc.pku.edu.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757153Ab2JSIpW (ORCPT ); Fri, 19 Oct 2012 04:45:22 -0400 From: Guan Xuetao To: linux-kernel@vger.kernel.org Cc: Al Viro Subject: [PATCH 1/2] unicore32: switch to generic kernel_thread()/kernel_execve() Date: Fri, 19 Oct 2012 16:43:09 +0800 Message-Id: <1350636190-6303-1-git-send-email-gxt@mprc.pku.edu.cn> X-Mailer: git-send-email 1.7.0.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6743 Lines: 217 From: Al Viro Signed-off-by: Al Viro Acked-and-Tested-by: Guan Xuetao --- arch/unicore32/Kconfig | 2 + arch/unicore32/include/asm/processor.h | 5 --- arch/unicore32/kernel/entry.S | 15 ++++---- arch/unicore32/kernel/process.c | 58 ++++++++------------------------ arch/unicore32/kernel/sys.c | 42 ----------------------- 5 files changed, 23 insertions(+), 99 deletions(-) diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig index 5b95ba4..fda37c9 100644 --- a/arch/unicore32/Kconfig +++ b/arch/unicore32/Kconfig @@ -16,6 +16,8 @@ config UNICORE32 select ARCH_WANT_FRAME_POINTERS select GENERIC_IOMAP select MODULES_USE_ELF_REL + select GENERIC_KERNEL_THREAD + select GENERIC_KERNEL_EXECVE help UniCore-32 is 32-bit Instruction Set Architecture, including a series of low-power-consumption RISC chip diff --git a/arch/unicore32/include/asm/processor.h b/arch/unicore32/include/asm/processor.h index 14382cb..4eaa421 100644 --- a/arch/unicore32/include/asm/processor.h +++ b/arch/unicore32/include/asm/processor.h @@ -72,11 +72,6 @@ unsigned long get_wchan(struct task_struct *p); #define cpu_relax() barrier() -/* - * Create a new kernel thread - */ -extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); - #define task_pt_regs(p) \ ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1) diff --git a/arch/unicore32/kernel/entry.S b/arch/unicore32/kernel/entry.S index dcb87ab..32648c9 100644 --- a/arch/unicore32/kernel/entry.S +++ b/arch/unicore32/kernel/entry.S @@ -573,17 +573,16 @@ ENDPROC(ret_to_user) */ ENTRY(ret_from_fork) b.l schedule_tail - get_thread_info tsk - ldw r1, [tsk+], #TI_FLAGS @ check for syscall tracing - mov why, #1 - cand.a r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls? - beq ret_slow_syscall - mov r1, sp - mov r0, #1 @ trace exit [IP = 1] - b.l syscall_trace b ret_slow_syscall ENDPROC(ret_from_fork) +ENTRY(ret_from_kernel_thread) + b.l schedule_tail + mov r0, r5 + adr lr, ret_slow_syscall + mov pc, r4 +ENDPROC(ret_from_kernel_thread) + /*============================================================================= * SWI handler *----------------------------------------------------------------------------- diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c index b008586..a8fe265 100644 --- a/arch/unicore32/kernel/process.c +++ b/arch/unicore32/kernel/process.c @@ -258,6 +258,7 @@ void release_thread(struct task_struct *dead_task) } asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); +asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread"); int copy_thread(unsigned long clone_flags, unsigned long stack_start, @@ -266,17 +267,22 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start, struct thread_info *thread = task_thread_info(p); struct pt_regs *childregs = task_pt_regs(p); - *childregs = *regs; - childregs->UCreg_00 = 0; - childregs->UCreg_sp = stack_start; - memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); thread->cpu_context.sp = (unsigned long)childregs; - thread->cpu_context.pc = (unsigned long)ret_from_fork; - - if (clone_flags & CLONE_SETTLS) - childregs->UCreg_16 = regs->UCreg_03; + if (unlikely(!regs)) { + thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread; + thread->cpu_context.r4 = stack_start; + thread->cpu_context.r5 = stk_sz; + memset(childregs, 0, sizeof(struct pt_regs)); + } else { + thread->cpu_context.pc = (unsigned long)ret_from_fork; + *childregs = *regs; + childregs->UCreg_00 = 0; + childregs->UCreg_sp = stack_start; + if (clone_flags & CLONE_SETTLS) + childregs->UCreg_16 = regs->UCreg_03; + } return 0; } @@ -305,42 +311,6 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fp) } EXPORT_SYMBOL(dump_fpu); -/* - * Shuffle the argument into the correct register before calling the - * thread function. r1 is the thread argument, r2 is the pointer to - * the thread function, and r3 points to the exit function. - */ -asm(".pushsection .text\n" -" .align\n" -" .type kernel_thread_helper, #function\n" -"kernel_thread_helper:\n" -" mov.a asr, r7\n" -" mov r0, r4\n" -" mov lr, r6\n" -" mov pc, r5\n" -" .size kernel_thread_helper, . - kernel_thread_helper\n" -" .popsection"); - -/* - * Create a kernel thread. - */ -pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) -{ - struct pt_regs regs; - - memset(®s, 0, sizeof(regs)); - - regs.UCreg_04 = (unsigned long)arg; - regs.UCreg_05 = (unsigned long)fn; - regs.UCreg_06 = (unsigned long)do_exit; - regs.UCreg_07 = PRIV_MODE; - regs.UCreg_pc = (unsigned long)kernel_thread_helper; - regs.UCreg_asr = regs.UCreg_07 | PSR_I_BIT; - - return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); -} -EXPORT_SYMBOL(kernel_thread); - unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; diff --git a/arch/unicore32/kernel/sys.c b/arch/unicore32/kernel/sys.c index fabdee9..8b6e4cc 100644 --- a/arch/unicore32/kernel/sys.c +++ b/arch/unicore32/kernel/sys.c @@ -63,48 +63,6 @@ out: return error; } -int kernel_execve(const char *filename, - const char *const argv[], - const char *const envp[]) -{ - struct pt_regs regs; - int ret; - - memset(®s, 0, sizeof(struct pt_regs)); - ret = do_execve(filename, - (const char __user *const __user *)argv, - (const char __user *const __user *)envp, ®s); - if (ret < 0) - goto out; - - /* - * Save argc to the register structure for userspace. - */ - regs.UCreg_00 = ret; - - /* - * We were successful. We won't be returning to our caller, but - * instead to user space by manipulating the kernel stack. - */ - asm("add r0, %0, %1\n\t" - "mov r1, %2\n\t" - "mov r2, %3\n\t" - "mov r22, #0\n\t" /* not a syscall */ - "mov r23, %0\n\t" /* thread structure */ - "b.l memmove\n\t" /* copy regs to top of stack */ - "mov sp, r0\n\t" /* reposition stack pointer */ - "b ret_to_user" - : - : "r" (current_thread_info()), - "Ir" (THREAD_START_SP - sizeof(regs)), - "r" (®s), - "Ir" (sizeof(regs)) - : "r0", "r1", "r2", "r3", "ip", "lr", "memory"); - - out: - return ret; -} - /* Note: used by the compat code even in 64-bit Linux. */ SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len, unsigned long, prot, unsigned long, flags, -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/