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avr32: switch to generic kernel_thread()/kernel_execve()

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-10-15 02:23:22 -04:00
parent ddffeb8c4d
commit 5adc807f70
6 changed files with 27 additions and 83 deletions
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2
arch/avr32/Kconfig
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@ -17,6 +17,8 @@ config AVR32
select GENERIC_CLOCKEVENTS
select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_RELA
select GENERIC_KERNEL_THREAD
select GENERIC_KERNEL_EXECVE
help
AVR32 is a high-performance 32-bit RISC microprocessor core,
designed for cost-sensitive embedded applications, with particular

3
arch/avr32/include/asm/processor.h
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@ -142,9 +142,6 @@ struct task_struct;
/* Free all resources held by a thread */
extern void release_thread(struct task_struct *);
/* Create a kernel thread without removing it from tasklists */
extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
/* Return saved PC of a blocked thread */
#define thread_saved_pc(tsk) ((tsk)->thread.cpu_context.pc)

2
arch/avr32/kernel/Makefile
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@ -7,7 +7,7 @@ extra-y := head.o vmlinux.lds
obj-$(CONFIG_SUBARCH_AVR32B) += entry-avr32b.o
obj-y += syscall_table.o syscall-stubs.o irq.o
obj-y += setup.o traps.o ocd.o ptrace.o
obj-y += signal.o sys_avr32.o process.o time.o
obj-y += signal.o process.o time.o
obj-y += switch_to.o cpu.o
obj-$(CONFIG_MODULES) += module.o avr32_ksyms.o
obj-$(CONFIG_KPROBES) += kprobes.o

14
arch/avr32/kernel/entry-avr32b.S
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@ -251,13 +251,15 @@ syscall_badsys:
.global ret_from_fork
ret_from_fork:
call schedule_tail
mov r12, 0
rjmp syscall_return
/* check for syscall tracing */
get_thread_info r0
ld.w r1, r0[TI_flags]
andl r1, _TIF_ALLWORK_MASK, COH
brne syscall_exit_work
rjmp syscall_exit_cont
.global ret_from_kernel_thread
ret_from_kernel_thread:
call schedule_tail
mov r12, r0
mov lr, r2 /* syscall_return */
mov pc, r1
syscall_trace_enter:
pushm r8-r12

65
arch/avr32/kernel/process.c
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@ -68,44 +68,6 @@ void machine_restart(char *cmd)
while (1) ;
}
/*
* PC is actually discarded when returning from a system call -- the
* return address must be stored in LR. This function will make sure
* LR points to do_exit before starting the thread.
*
* Also, when returning from fork(), r12 is 0, so we must copy the
* argument as well.
*
* r0 : The argument to the main thread function
* r1 : The address of do_exit
* r2 : The address of the main thread function
*/
asmlinkage extern void kernel_thread_helper(void);
__asm__(" .type kernel_thread_helper, @function\n"
"kernel_thread_helper:\n"
" mov r12, r0\n"
" mov lr, r2\n"
" mov pc, r1\n"
" .size kernel_thread_helper, . - kernel_thread_helper");
int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
regs.r0 = (unsigned long)arg;
regs.r1 = (unsigned long)fn;
regs.r2 = (unsigned long)do_exit;
regs.lr = (unsigned long)kernel_thread_helper;
regs.pc = (unsigned long)kernel_thread_helper;
regs.sr = MODE_SUPERVISOR;
return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
0, &regs, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc
*/
@ -332,26 +294,31 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
}
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
asmlinkage void syscall_return(void);
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
struct pt_regs *childregs;
struct pt_regs *childregs = task_pt_regs(p);
childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)task_stack_page(p))) - 1;
*childregs = *regs;
if (user_mode(regs))
if (unlikely(!regs)) {
memset(childregs, 0, sizeof(struct pt_regs));
p->thread.cpu_context.r0 = arg;
p->thread.cpu_context.r1 = usp; /* fn */
p->thread.cpu_context.r2 = syscall_return;
p->thread.cpu_context.pc = (unsigned long)ret_from_kernel_thread;
childregs->sr = MODE_SUPERVISOR;
} else {
*childregs = *regs;
childregs->sp = usp;
else
childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
childregs->r12 = 0; /* Set return value for child */
childregs->r12 = 0; /* Set return value for child */
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
}
p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
p->thread.cpu_context.ksp = (unsigned long)childregs;
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
clear_tsk_thread_flag(p, TIF_DEBUG);
if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))

24
arch/avr32/kernel/sys_avr32.c
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@ -1,24 +0,0 @@
/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/unistd.h>
int kernel_execve(const char *file,
const char *const *argv,
const char *const *envp)
{
register long scno asm("r8") = __NR_execve;
register long sc1 asm("r12") = (long)file;
register long sc2 asm("r11") = (long)argv;
register long sc3 asm("r10") = (long)envp;
asm volatile("scall"
: "=r"(sc1)
: "r"(scno), "0"(sc1), "r"(sc2), "r"(sc3)
: "cc", "memory");
return sc1;
}