From a44e060fc523c379341e35a981c09c3953cf4ba4 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 3 Oct 2012 23:28:08 -0400 Subject: [PATCH] parisc: switch to generic kernel_thread() Signed-off-by: Al Viro --- arch/parisc/Kconfig | 1 + arch/parisc/kernel/entry.S | 53 +----------------------------------- arch/parisc/kernel/process.c | 53 +++++++++++------------------------- 3 files changed, 18 insertions(+), 89 deletions(-) diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 11def45b98c..c779da7cd96 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -22,6 +22,7 @@ config PARISC select GENERIC_STRNCPY_FROM_USER select HAVE_MOD_ARCH_SPECIFIC select MODULES_USE_ELF_RELA + select GENERIC_KERNEL_THREAD help The PA-RISC microprocessor is designed by Hewlett-Packard and used diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 18670a07884..18d05e7373b 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -707,60 +707,10 @@ ENTRY(end_fault_vector) .import handle_interruption,code .import do_cpu_irq_mask,code - /* - * r26 = function to be called - * r25 = argument to pass in - * r24 = flags for do_fork() - * - * Kernel threads don't ever return, so they don't need - * a true register context. We just save away the arguments - * for copy_thread/ret_ to properly set up the child. - */ - -#define CLONE_VM 0x100 /* Must agree with */ -#define CLONE_UNTRACED 0x00800000 - - .import do_fork -ENTRY(__kernel_thread) - STREG %r2, -RP_OFFSET(%r30) - - copy %r30, %r1 - ldo PT_SZ_ALGN(%r30),%r30 -#ifdef CONFIG_64BIT - /* Yo, function pointers in wide mode are little structs... -PB */ - ldd 24(%r26), %r2 - STREG %r2, PT_GR27(%r1) /* Store childs %dp */ - ldd 16(%r26), %r26 - - STREG %r22, PT_GR22(%r1) /* save r22 (arg5) */ - copy %r0, %r22 /* user_tid */ -#endif - STREG %r26, PT_GR26(%r1) /* Store function & argument for child */ - STREG %r25, PT_GR25(%r1) - ldil L%CLONE_UNTRACED, %r26 - ldo CLONE_VM(%r26), %r26 /* Force CLONE_VM since only init_mm */ - or %r26, %r24, %r26 /* will have kernel mappings. */ - ldi 1, %r25 /* stack_start, signals kernel thread */ - stw %r0, -52(%r30) /* user_tid */ -#ifdef CONFIG_64BIT - ldo -16(%r30),%r29 /* Reference param save area */ -#endif - BL do_fork, %r2 - copy %r1, %r24 /* pt_regs */ - - /* Parent Returns here */ - - LDREG -PT_SZ_ALGN-RP_OFFSET(%r30), %r2 - ldo -PT_SZ_ALGN(%r30), %r30 - bv %r0(%r2) - nop -ENDPROC(__kernel_thread) - /* * Child Returns here * - * copy_thread moved args from temp save area set up above - * into task save area. + * copy_thread moved args into task save area. */ ENTRY(ret_from_kernel_thread) @@ -773,7 +723,6 @@ ENTRY(ret_from_kernel_thread) LDREG TASK_PT_GR25(%r1), %r26 #ifdef CONFIG_64BIT LDREG TASK_PT_GR27(%r1), %r27 - LDREG TASK_PT_GR22(%r1), %r22 #endif LDREG TASK_PT_GR26(%r1), %r1 ble 0(%sr7, %r1) diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c index cbc37216bf9..b7b4126774e 100644 --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -164,23 +164,6 @@ void machine_power_off(void) void (*pm_power_off)(void) = machine_power_off; EXPORT_SYMBOL(pm_power_off); -/* - * Create a kernel thread - */ - -extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); -pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) -{ - - /* - * FIXME: Once we are sure we don't need any debug here, - * kernel_thread can become a #define. - */ - - return __kernel_thread(fn, arg, flags); -} -EXPORT_SYMBOL(kernel_thread); - /* * Free current thread data structures etc.. */ @@ -256,8 +239,8 @@ sys_vfork(struct pt_regs *regs) int copy_thread(unsigned long clone_flags, unsigned long usp, - unsigned long unused, /* in ia64 this is "user_stack_size" */ - struct task_struct * p, struct pt_regs * pregs) + unsigned long arg, + struct task_struct *p, struct pt_regs *pregs) { struct pt_regs * cregs = &(p->thread.regs); void *stack = task_stack_page(p); @@ -271,21 +254,8 @@ copy_thread(unsigned long clone_flags, unsigned long usp, extern void * const hpux_child_return; #endif - *cregs = *pregs; - - /* Set the return value for the child. Note that this is not - actually restored by the syscall exit path, but we put it - here for consistency in case of signals. */ - cregs->gr[28] = 0; /* child */ - - /* - * We need to differentiate between a user fork and a - * kernel fork. We can't use user_mode, because the - * the syscall path doesn't save iaoq. Right now - * We rely on the fact that kernel_thread passes - * in zero for usp. - */ - if (usp == 1) { + if (unlikely((p->flags & PF_KTHREAD) && usp != 0)) { + memset(cregs, 0, sizeof(struct pt_regs)); /* kernel thread */ cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN; /* Must exit via ret_from_kernel_thread in order @@ -297,10 +267,12 @@ copy_thread(unsigned long clone_flags, unsigned long usp, * ret_from_kernel_thread. */ #ifdef CONFIG_64BIT - cregs->gr[27] = pregs->gr[27]; + cregs->gr[27] = ((unsigned long *)usp)[3]; + cregs->gr[26] = ((unsigned long *)usp)[2]; +#else + cregs->gr[26] = usp; #endif - cregs->gr[26] = pregs->gr[26]; - cregs->gr[25] = pregs->gr[25]; + cregs->gr[25] = arg; } else { /* user thread */ /* @@ -308,6 +280,13 @@ copy_thread(unsigned long clone_flags, unsigned long usp, * for setting gr[21]. */ + *cregs = *pregs; + + /* Set the return value for the child. Note that this is not + actually restored by the syscall exit path, but we put it + here for consistency in case of signals. */ + cregs->gr[28] = 0; /* child */ + /* Use same stack depth as parent */ cregs->ksp = (unsigned long)stack + (pregs->gr[21] & (THREAD_SIZE - 1)); -- 2.46.0