d7627467b7
Make do_execve() take a const filename pointer so that kernel_execve() compiles correctly on ARM: arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type This also requires the argv and envp arguments to be consted twice, once for the pointer array and once for the strings the array points to. This is because do_execve() passes a pointer to the filename (now const) to copy_strings_kernel(). A simpler alternative would be to cast the filename pointer in do_execve() when it's passed to copy_strings_kernel(). do_execve() may not change any of the strings it is passed as part of the argv or envp lists as they are some of them in .rodata, so marking these strings as const should be fine. Further kernel_execve() and sys_execve() need to be changed to match. This has been test built on x86_64, frv, arm and mips. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
340 lines
8.1 KiB
C
340 lines
8.1 KiB
C
/*
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* arch/sh/kernel/process.c
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*
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* This file handles the architecture-dependent parts of process handling..
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*
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* Copyright (C) 1995 Linus Torvalds
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*
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* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
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* Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
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* Copyright (C) 2002 - 2008 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/elfcore.h>
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#include <linux/kallsyms.h>
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#include <linux/fs.h>
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#include <linux/ftrace.h>
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#include <linux/hw_breakpoint.h>
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#include <asm/uaccess.h>
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#include <asm/mmu_context.h>
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#include <asm/system.h>
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#include <asm/fpu.h>
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#include <asm/syscalls.h>
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void show_regs(struct pt_regs * regs)
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{
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printk("\n");
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printk("Pid : %d, Comm: \t\t%s\n", task_pid_nr(current), current->comm);
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printk("CPU : %d \t\t%s (%s %.*s)\n\n",
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smp_processor_id(), print_tainted(), init_utsname()->release,
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(int)strcspn(init_utsname()->version, " "),
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init_utsname()->version);
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print_symbol("PC is at %s\n", instruction_pointer(regs));
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print_symbol("PR is at %s\n", regs->pr);
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printk("PC : %08lx SP : %08lx SR : %08lx ",
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regs->pc, regs->regs[15], regs->sr);
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#ifdef CONFIG_MMU
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printk("TEA : %08x\n", __raw_readl(MMU_TEA));
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#else
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printk("\n");
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#endif
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printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
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regs->regs[0],regs->regs[1],
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regs->regs[2],regs->regs[3]);
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printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
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regs->regs[4],regs->regs[5],
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regs->regs[6],regs->regs[7]);
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printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
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regs->regs[8],regs->regs[9],
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regs->regs[10],regs->regs[11]);
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printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
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regs->regs[12],regs->regs[13],
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regs->regs[14]);
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printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
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regs->mach, regs->macl, regs->gbr, regs->pr);
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show_trace(NULL, (unsigned long *)regs->regs[15], regs);
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show_code(regs);
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}
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/*
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* Create a kernel thread
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*/
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ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *))
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{
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do_exit(fn(arg));
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}
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/* Don't use this in BL=1(cli). Or else, CPU resets! */
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int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
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{
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struct pt_regs regs;
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int pid;
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memset(®s, 0, sizeof(regs));
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regs.regs[4] = (unsigned long)arg;
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regs.regs[5] = (unsigned long)fn;
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regs.pc = (unsigned long)kernel_thread_helper;
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regs.sr = SR_MD;
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#if defined(CONFIG_SH_FPU)
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regs.sr |= SR_FD;
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#endif
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/* Ok, create the new process.. */
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pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
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®s, 0, NULL, NULL);
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return pid;
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}
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EXPORT_SYMBOL(kernel_thread);
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void start_thread(struct pt_regs *regs, unsigned long new_pc,
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unsigned long new_sp)
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{
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set_fs(USER_DS);
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regs->pr = 0;
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regs->sr = SR_FD;
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regs->pc = new_pc;
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regs->regs[15] = new_sp;
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free_thread_xstate(current);
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}
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EXPORT_SYMBOL(start_thread);
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/*
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* Free current thread data structures etc..
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*/
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void exit_thread(void)
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{
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}
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void flush_thread(void)
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{
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struct task_struct *tsk = current;
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flush_ptrace_hw_breakpoint(tsk);
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#if defined(CONFIG_SH_FPU)
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/* Forget lazy FPU state */
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clear_fpu(tsk, task_pt_regs(tsk));
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clear_used_math();
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#endif
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}
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void release_thread(struct task_struct *dead_task)
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{
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/* do nothing */
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}
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/* Fill in the fpu structure for a core dump.. */
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int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
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{
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int fpvalid = 0;
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#if defined(CONFIG_SH_FPU)
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struct task_struct *tsk = current;
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fpvalid = !!tsk_used_math(tsk);
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if (fpvalid)
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fpvalid = !fpregs_get(tsk, NULL, 0,
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sizeof(struct user_fpu_struct),
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fpu, NULL);
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#endif
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return fpvalid;
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}
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EXPORT_SYMBOL(dump_fpu);
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/*
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* This gets called before we allocate a new thread and copy
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* the current task into it.
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*/
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void prepare_to_copy(struct task_struct *tsk)
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{
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unlazy_fpu(tsk, task_pt_regs(tsk));
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}
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asmlinkage void ret_from_fork(void);
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int copy_thread(unsigned long clone_flags, unsigned long usp,
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unsigned long unused,
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struct task_struct *p, struct pt_regs *regs)
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{
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struct thread_info *ti = task_thread_info(p);
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struct pt_regs *childregs;
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#if defined(CONFIG_SH_DSP)
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struct task_struct *tsk = current;
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if (is_dsp_enabled(tsk)) {
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/* We can use the __save_dsp or just copy the struct:
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* __save_dsp(p);
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* p->thread.dsp_status.status |= SR_DSP
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*/
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p->thread.dsp_status = tsk->thread.dsp_status;
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}
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#endif
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childregs = task_pt_regs(p);
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*childregs = *regs;
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if (user_mode(regs)) {
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childregs->regs[15] = usp;
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ti->addr_limit = USER_DS;
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} else {
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childregs->regs[15] = (unsigned long)childregs;
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ti->addr_limit = KERNEL_DS;
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ti->status &= ~TS_USEDFPU;
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p->fpu_counter = 0;
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}
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if (clone_flags & CLONE_SETTLS)
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childregs->gbr = childregs->regs[0];
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childregs->regs[0] = 0; /* Set return value for child */
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p->thread.sp = (unsigned long) childregs;
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p->thread.pc = (unsigned long) ret_from_fork;
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memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
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return 0;
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}
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/*
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* switch_to(x,y) should switch tasks from x to y.
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*
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*/
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__notrace_funcgraph struct task_struct *
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__switch_to(struct task_struct *prev, struct task_struct *next)
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{
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struct thread_struct *next_t = &next->thread;
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unlazy_fpu(prev, task_pt_regs(prev));
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/* we're going to use this soon, after a few expensive things */
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if (next->fpu_counter > 5)
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prefetch(next_t->xstate);
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#ifdef CONFIG_MMU
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/*
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* Restore the kernel mode register
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* k7 (r7_bank1)
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*/
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asm volatile("ldc %0, r7_bank"
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: /* no output */
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: "r" (task_thread_info(next)));
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#endif
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/*
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* If the task has used fpu the last 5 timeslices, just do a full
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* restore of the math state immediately to avoid the trap; the
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* chances of needing FPU soon are obviously high now
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*/
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if (next->fpu_counter > 5)
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__fpu_state_restore();
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return prev;
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}
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asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
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unsigned long r6, unsigned long r7,
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struct pt_regs __regs)
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{
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#ifdef CONFIG_MMU
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struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
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return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
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#else
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/* fork almost works, enough to trick you into looking elsewhere :-( */
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return -EINVAL;
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#endif
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}
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asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
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unsigned long parent_tidptr,
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unsigned long child_tidptr,
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struct pt_regs __regs)
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{
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struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
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if (!newsp)
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newsp = regs->regs[15];
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return do_fork(clone_flags, newsp, regs, 0,
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(int __user *)parent_tidptr,
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(int __user *)child_tidptr);
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}
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/*
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* This is trivial, and on the face of it looks like it
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* could equally well be done in user mode.
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*
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* Not so, for quite unobvious reasons - register pressure.
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* In user mode vfork() cannot have a stack frame, and if
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* done by calling the "clone()" system call directly, you
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* do not have enough call-clobbered registers to hold all
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* the information you need.
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*/
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asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
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unsigned long r6, unsigned long r7,
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struct pt_regs __regs)
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{
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struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
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return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
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0, NULL, NULL);
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}
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/*
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* sys_execve() executes a new program.
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*/
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asmlinkage int sys_execve(const char __user *ufilename,
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const char __user *const __user *uargv,
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const char __user *const __user *uenvp,
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unsigned long r7, struct pt_regs __regs)
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{
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struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
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int error;
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char *filename;
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filename = getname(ufilename);
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error = PTR_ERR(filename);
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if (IS_ERR(filename))
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goto out;
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error = do_execve(filename, uargv, uenvp, regs);
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putname(filename);
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out:
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return error;
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}
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unsigned long get_wchan(struct task_struct *p)
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{
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unsigned long pc;
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if (!p || p == current || p->state == TASK_RUNNING)
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return 0;
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/*
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* The same comment as on the Alpha applies here, too ...
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*/
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pc = thread_saved_pc(p);
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#ifdef CONFIG_FRAME_POINTER
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if (in_sched_functions(pc)) {
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unsigned long schedule_frame = (unsigned long)p->thread.sp;
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return ((unsigned long *)schedule_frame)[21];
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}
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#endif
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return pc;
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}
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