c52d0d30ae
This is a preliminary patch to add a vdso to all user processes. Still missing are ELF headers and .eh_frame information. But it is enough to allow us to move signal trampolines off of the stack. Note that emulation of branch delay slots in the FPU emulator still requires the stack. We allocate a single page (the vdso) and write all possible signal trampolines into it. The stack is moved down by one page and the vdso is mapped into this space. Signed-off-by: David Daney <ddaney@caviumnetworks.com> To: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/975/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
415 lines
9.6 KiB
C
415 lines
9.6 KiB
C
/*
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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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* Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
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* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
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* Copyright (C) 2001 MIPS Technologies, Inc.
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*/
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#include <linux/capability.h>
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#include <linux/errno.h>
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#include <linux/linkage.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/smp.h>
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#include <linux/mman.h>
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#include <linux/ptrace.h>
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#include <linux/sched.h>
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#include <linux/string.h>
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#include <linux/syscalls.h>
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#include <linux/file.h>
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#include <linux/utsname.h>
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#include <linux/unistd.h>
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#include <linux/sem.h>
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#include <linux/msg.h>
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#include <linux/shm.h>
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#include <linux/compiler.h>
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#include <linux/module.h>
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#include <linux/ipc.h>
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#include <linux/uaccess.h>
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#include <linux/slab.h>
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#include <asm/asm.h>
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#include <asm/branch.h>
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#include <asm/cachectl.h>
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#include <asm/cacheflush.h>
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#include <asm/asm-offsets.h>
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#include <asm/signal.h>
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#include <asm/sim.h>
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#include <asm/shmparam.h>
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#include <asm/sysmips.h>
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#include <asm/uaccess.h>
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/*
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* For historic reasons the pipe(2) syscall on MIPS has an unusual calling
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* convention. It returns results in registers $v0 / $v1 which means there
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* is no need for it to do verify the validity of a userspace pointer
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* argument. Historically that used to be expensive in Linux. These days
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* the performance advantage is negligible.
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*/
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asmlinkage int sysm_pipe(nabi_no_regargs volatile struct pt_regs regs)
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{
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int fd[2];
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int error, res;
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error = do_pipe_flags(fd, 0);
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if (error) {
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res = error;
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goto out;
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}
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regs.regs[3] = fd[1];
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res = fd[0];
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out:
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return res;
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}
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unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
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EXPORT_SYMBOL(shm_align_mask);
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#define COLOUR_ALIGN(addr,pgoff) \
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((((addr) + shm_align_mask) & ~shm_align_mask) + \
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(((pgoff) << PAGE_SHIFT) & shm_align_mask))
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unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct vm_area_struct * vmm;
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int do_color_align;
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unsigned long task_size;
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#ifdef CONFIG_32BIT
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task_size = TASK_SIZE;
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#else /* Must be CONFIG_64BIT*/
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task_size = test_thread_flag(TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE;
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#endif
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if (len > task_size)
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return -ENOMEM;
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if (flags & MAP_FIXED) {
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/* Even MAP_FIXED mappings must reside within task_size. */
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if (task_size - len < addr)
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return -EINVAL;
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/*
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* We do not accept a shared mapping if it would violate
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* cache aliasing constraints.
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*/
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if ((flags & MAP_SHARED) &&
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((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
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return -EINVAL;
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return addr;
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}
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do_color_align = 0;
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if (filp || (flags & MAP_SHARED))
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do_color_align = 1;
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if (addr) {
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if (do_color_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(addr);
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vmm = find_vma(current->mm, addr);
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if (task_size - len >= addr &&
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(!vmm || addr + len <= vmm->vm_start))
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return addr;
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}
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addr = TASK_UNMAPPED_BASE;
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if (do_color_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(addr);
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for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
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/* At this point: (!vmm || addr < vmm->vm_end). */
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if (task_size - len < addr)
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return -ENOMEM;
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if (!vmm || addr + len <= vmm->vm_start)
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return addr;
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addr = vmm->vm_end;
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if (do_color_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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}
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}
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SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
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unsigned long, prot, unsigned long, flags, unsigned long,
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fd, off_t, offset)
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{
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unsigned long result;
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result = -EINVAL;
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if (offset & ~PAGE_MASK)
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goto out;
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result = sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
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out:
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return result;
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}
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SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
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unsigned long, prot, unsigned long, flags, unsigned long, fd,
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unsigned long, pgoff)
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{
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if (pgoff & (~PAGE_MASK >> 12))
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return -EINVAL;
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return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));
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}
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save_static_function(sys_fork);
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static int __used noinline
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_sys_fork(nabi_no_regargs struct pt_regs regs)
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{
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return do_fork(SIGCHLD, regs.regs[29], ®s, 0, NULL, NULL);
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}
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save_static_function(sys_clone);
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static int __used noinline
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_sys_clone(nabi_no_regargs struct pt_regs regs)
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{
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unsigned long clone_flags;
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unsigned long newsp;
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int __user *parent_tidptr, *child_tidptr;
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clone_flags = regs.regs[4];
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newsp = regs.regs[5];
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if (!newsp)
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newsp = regs.regs[29];
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parent_tidptr = (int __user *) regs.regs[6];
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#ifdef CONFIG_32BIT
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/* We need to fetch the fifth argument off the stack. */
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child_tidptr = NULL;
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if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
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int __user *__user *usp = (int __user *__user *) regs.regs[29];
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if (regs.regs[2] == __NR_syscall) {
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if (get_user (child_tidptr, &usp[5]))
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return -EFAULT;
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}
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else if (get_user (child_tidptr, &usp[4]))
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return -EFAULT;
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}
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#else
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child_tidptr = (int __user *) regs.regs[8];
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#endif
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return do_fork(clone_flags, newsp, ®s, 0,
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parent_tidptr, child_tidptr);
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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(nabi_no_regargs struct pt_regs regs)
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{
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int error;
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char * filename;
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filename = getname((char __user *) (long)regs.regs[4]);
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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, (char __user *__user *) (long)regs.regs[5],
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(char __user *__user *) (long)regs.regs[6], ®s);
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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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SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
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{
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struct thread_info *ti = task_thread_info(current);
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ti->tp_value = addr;
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if (cpu_has_userlocal)
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write_c0_userlocal(addr);
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return 0;
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}
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static inline int mips_atomic_set(struct pt_regs *regs,
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unsigned long addr, unsigned long new)
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{
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unsigned long old, tmp;
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unsigned int err;
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if (unlikely(addr & 3))
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return -EINVAL;
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if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
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return -EINVAL;
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if (cpu_has_llsc && R10000_LLSC_WAR) {
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__asm__ __volatile__ (
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" .set mips3 \n"
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" li %[err], 0 \n"
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"1: ll %[old], (%[addr]) \n"
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" move %[tmp], %[new] \n"
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"2: sc %[tmp], (%[addr]) \n"
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" beqzl %[tmp], 1b \n"
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"3: \n"
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" .section .fixup,\"ax\" \n"
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"4: li %[err], %[efault] \n"
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" j 3b \n"
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" .previous \n"
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" .section __ex_table,\"a\" \n"
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" "STR(PTR)" 1b, 4b \n"
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" "STR(PTR)" 2b, 4b \n"
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" .previous \n"
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" .set mips0 \n"
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: [old] "=&r" (old),
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[err] "=&r" (err),
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[tmp] "=&r" (tmp)
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: [addr] "r" (addr),
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[new] "r" (new),
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[efault] "i" (-EFAULT)
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: "memory");
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} else if (cpu_has_llsc) {
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__asm__ __volatile__ (
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" .set mips3 \n"
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" li %[err], 0 \n"
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"1: ll %[old], (%[addr]) \n"
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" move %[tmp], %[new] \n"
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"2: sc %[tmp], (%[addr]) \n"
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" bnez %[tmp], 4f \n"
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"3: \n"
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" .subsection 2 \n"
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"4: b 1b \n"
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" .previous \n"
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" \n"
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" .section .fixup,\"ax\" \n"
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"5: li %[err], %[efault] \n"
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" j 3b \n"
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" .previous \n"
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" .section __ex_table,\"a\" \n"
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" "STR(PTR)" 1b, 5b \n"
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" "STR(PTR)" 2b, 5b \n"
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" .previous \n"
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" .set mips0 \n"
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: [old] "=&r" (old),
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[err] "=&r" (err),
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[tmp] "=&r" (tmp)
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: [addr] "r" (addr),
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[new] "r" (new),
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[efault] "i" (-EFAULT)
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: "memory");
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} else {
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do {
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preempt_disable();
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ll_bit = 1;
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ll_task = current;
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preempt_enable();
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err = __get_user(old, (unsigned int *) addr);
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err |= __put_user(new, (unsigned int *) addr);
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if (err)
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break;
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rmb();
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} while (!ll_bit);
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}
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if (unlikely(err))
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return err;
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regs->regs[2] = old;
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regs->regs[7] = 0; /* No error */
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/*
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* Don't let your children do this ...
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*/
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__asm__ __volatile__(
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" move $29, %0 \n"
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" j syscall_exit \n"
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: /* no outputs */
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: "r" (regs));
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/* unreached. Honestly. */
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while (1);
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}
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save_static_function(sys_sysmips);
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static int __used noinline
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_sys_sysmips(nabi_no_regargs struct pt_regs regs)
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{
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long cmd, arg1, arg2, arg3;
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cmd = regs.regs[4];
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arg1 = regs.regs[5];
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arg2 = regs.regs[6];
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arg3 = regs.regs[7];
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switch (cmd) {
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case MIPS_ATOMIC_SET:
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return mips_atomic_set(®s, arg1, arg2);
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case MIPS_FIXADE:
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if (arg1 & ~3)
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return -EINVAL;
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if (arg1 & 1)
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set_thread_flag(TIF_FIXADE);
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else
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clear_thread_flag(TIF_FIXADE);
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if (arg1 & 2)
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set_thread_flag(TIF_LOGADE);
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else
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clear_thread_flag(TIF_FIXADE);
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return 0;
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case FLUSH_CACHE:
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__flush_cache_all();
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return 0;
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}
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return -EINVAL;
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}
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/*
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* No implemented yet ...
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*/
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SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
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{
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return -ENOSYS;
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}
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/*
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* If we ever come here the user sp is bad. Zap the process right away.
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* Due to the bad stack signaling wouldn't work.
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*/
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asmlinkage void bad_stack(void)
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{
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do_exit(SIGSEGV);
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}
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/*
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* Do a system call from kernel instead of calling sys_execve so we
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* end up with proper pt_regs.
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*/
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int kernel_execve(const char *filename, char *const argv[], char *const envp[])
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{
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register unsigned long __a0 asm("$4") = (unsigned long) filename;
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register unsigned long __a1 asm("$5") = (unsigned long) argv;
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register unsigned long __a2 asm("$6") = (unsigned long) envp;
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register unsigned long __a3 asm("$7");
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unsigned long __v0;
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__asm__ volatile (" \n"
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" .set noreorder \n"
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" li $2, %5 # __NR_execve \n"
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" syscall \n"
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" move %0, $2 \n"
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" .set reorder \n"
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: "=&r" (__v0), "=r" (__a3)
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: "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
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: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
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"memory");
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if (__a3 == 0)
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return __v0;
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return -__v0;
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}
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