diff options
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/calls.S | 2 | ||||
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 29 | ||||
| -rw-r--r-- | arch/arm/kernel/process.c | 75 | ||||
| -rw-r--r-- | arch/arm/kernel/sys_arm.c | 63 |
4 files changed, 38 insertions, 131 deletions
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index e337879595e5..831cd38c8d99 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -20,7 +20,7 @@ CALL(sys_creat) CALL(sys_link) /* 10 */ CALL(sys_unlink) - CALL(sys_execve_wrapper) + CALL(sys_execve) CALL(sys_chdir) CALL(OBSOLETE(sys_time)) /* used by libc4 */ CALL(sys_mknod) diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index f45987037bf1..e340fa1db203 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -91,6 +91,30 @@ ENTRY(ret_from_fork) b ret_slow_syscall ENDPROC(ret_from_fork) +ENTRY(ret_from_kernel_thread) + UNWIND(.fnstart) + UNWIND(.cantunwind) + bl schedule_tail + mov r0, r4 + adr lr, BSYM(1f) @ kernel threads should not exit + mov pc, r5 +1: bl do_exit + nop + UNWIND(.fnend) +ENDPROC(ret_from_kernel_thread) + +/* + * turn a kernel thread into userland process + * use: ret_from_kernel_execve(struct pt_regs *normal) + */ +ENTRY(ret_from_kernel_execve) + mov why, #0 @ not a syscall + str why, [r0, #S_R0] @ ... and we want 0 in ->ARM_r0 as well + get_thread_info tsk @ thread structure + mov sp, r0 @ stack pointer just under pt_regs + b ret_slow_syscall +ENDPROC(ret_from_kernel_execve) + .equ NR_syscalls,0 #define CALL(x) .equ NR_syscalls,NR_syscalls+1 #include "calls.S" @@ -517,11 +541,6 @@ sys_vfork_wrapper: b sys_vfork ENDPROC(sys_vfork_wrapper) -sys_execve_wrapper: - add r3, sp, #S_OFF - b sys_execve -ENDPROC(sys_execve_wrapper) - sys_clone_wrapper: add ip, sp, #S_OFF str ip, [sp, #4] diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 04eea22d7958..f98c17ff1957 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -373,6 +373,7 @@ 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, @@ -381,13 +382,20 @@ 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->ARM_r0 = 0; - childregs->ARM_sp = stack_start; - memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); + + if (likely(regs)) { + *childregs = *regs; + childregs->ARM_r0 = 0; + childregs->ARM_sp = stack_start; + thread->cpu_context.pc = (unsigned long)ret_from_fork; + } else { + thread->cpu_context.r4 = stk_sz; + thread->cpu_context.r5 = stack_start; + thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread; + childregs->ARM_cpsr = SVC_MODE; + } thread->cpu_context.sp = (unsigned long)childregs; - thread->cpu_context.pc = (unsigned long)ret_from_fork; clear_ptrace_hw_breakpoint(p); @@ -423,63 +431,6 @@ int dump_fpu (struct pt_regs *regs, struct user_fp *fp) } EXPORT_SYMBOL(dump_fpu); -/* - * Shuffle the argument into the correct register before calling the - * thread function. r4 is the thread argument, r5 is the pointer to - * the thread function, and r6 points to the exit function. - */ -extern void kernel_thread_helper(void); -asm( ".pushsection .text\n" -" .align\n" -" .type kernel_thread_helper, #function\n" -"kernel_thread_helper:\n" -#ifdef CONFIG_TRACE_IRQFLAGS -" bl trace_hardirqs_on\n" -#endif -" msr cpsr_c, r7\n" -" mov r0, r4\n" -" mov lr, r6\n" -" mov pc, r5\n" -" .size kernel_thread_helper, . - kernel_thread_helper\n" -" .popsection"); - -#ifdef CONFIG_ARM_UNWIND -extern void kernel_thread_exit(long code); -asm( ".pushsection .text\n" -" .align\n" -" .type kernel_thread_exit, #function\n" -"kernel_thread_exit:\n" -" .fnstart\n" -" .cantunwind\n" -" bl do_exit\n" -" nop\n" -" .fnend\n" -" .size kernel_thread_exit, . - kernel_thread_exit\n" -" .popsection"); -#else -#define kernel_thread_exit do_exit -#endif - -/* - * 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.ARM_r4 = (unsigned long)arg; - regs.ARM_r5 = (unsigned long)fn; - regs.ARM_r6 = (unsigned long)kernel_thread_exit; - regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE; - regs.ARM_pc = (unsigned long)kernel_thread_helper; - regs.ARM_cpsr = regs.ARM_r7 | 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/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c index 76cbb055dd05..c2a898aa57aa 100644 --- a/arch/arm/kernel/sys_arm.c +++ b/arch/arm/kernel/sys_arm.c @@ -59,69 +59,6 @@ asmlinkage int sys_vfork(struct pt_regs *regs) return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL); } -/* sys_execve() executes a new program. - * This is called indirectly via a small wrapper - */ -asmlinkage int sys_execve(const char __user *filenamei, - const char __user *const __user *argv, - const char __user *const __user *envp, struct pt_regs *regs) -{ - int error; - char * filename; - - filename = getname(filenamei); - error = PTR_ERR(filename); - if (IS_ERR(filename)) - goto out; - error = do_execve(filename, argv, envp, regs); - putname(filename); -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.ARM_r0 = 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" - "bl memmove\n\t" /* copy regs to top of stack */ - "mov r8, #0\n\t" /* not a syscall */ - "mov r9, %0\n\t" /* thread structure */ - "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", "r8", "r9", "ip", "lr", "memory"); - - out: - return ret; -} -EXPORT_SYMBOL(kernel_execve); - /* * Since loff_t is a 64 bit type we avoid a lot of ABI hassle * with a different argument ordering. |