91a27b2a75
getname() is intended to copy pathname strings from userspace into a kernel buffer. The result is just a string in kernel space. It would however be quite helpful to be able to attach some ancillary info to the string. For instance, we could attach some audit-related info to reduce the amount of audit-related processing needed. When auditing is enabled, we could also call getname() on the string more than once and not need to recopy it from userspace. This patchset converts the getname()/putname() interfaces to return a struct instead of a string. For now, the struct just tracks the string in kernel space and the original userland pointer for it. Later, we'll add other information to the struct as it becomes convenient. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
139 lines
3.6 KiB
C
139 lines
3.6 KiB
C
/*
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* AArch64-specific system calls implementation
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*
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* Copyright (C) 2012 ARM Ltd.
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* Author: Catalin Marinas <catalin.marinas@arm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/compiler.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/syscalls.h>
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/*
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* Clone a task - this clones the calling program thread.
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*/
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asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
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int __user *parent_tidptr, unsigned long tls_val,
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int __user *child_tidptr, struct pt_regs *regs)
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{
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if (!newsp)
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newsp = regs->sp;
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/* 16-byte aligned stack mandatory on AArch64 */
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if (newsp & 15)
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return -EINVAL;
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return do_fork(clone_flags, newsp, regs, 0, 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 long sys_execve(const char __user *filenamei,
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const char __user *const __user *argv,
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const char __user *const __user *envp,
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struct pt_regs *regs)
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{
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long error;
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struct filename *filename;
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filename = getname(filenamei);
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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->name, argv, envp, 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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int kernel_execve(const char *filename,
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const char *const argv[],
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const char *const envp[])
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{
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struct pt_regs regs;
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int ret;
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memset(®s, 0, sizeof(struct pt_regs));
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ret = do_execve(filename,
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(const char __user *const __user *)argv,
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(const char __user *const __user *)envp, ®s);
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if (ret < 0)
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goto out;
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/*
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* Save argc to the register structure for userspace.
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*/
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regs.regs[0] = ret;
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/*
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* We were successful. We won't be returning to our caller, but
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* instead to user space by manipulating the kernel stack.
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*/
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asm( "add x0, %0, %1\n\t"
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"mov x1, %2\n\t"
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"mov x2, %3\n\t"
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"bl memmove\n\t" /* copy regs to top of stack */
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"mov x27, #0\n\t" /* not a syscall */
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"mov x28, %0\n\t" /* thread structure */
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"mov sp, x0\n\t" /* reposition stack pointer */
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"b ret_to_user"
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:
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: "r" (current_thread_info()),
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"Ir" (THREAD_START_SP - sizeof(regs)),
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"r" (®s),
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"Ir" (sizeof(regs))
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: "x0", "x1", "x2", "x27", "x28", "x30", "memory");
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out:
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return ret;
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}
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EXPORT_SYMBOL(kernel_execve);
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asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
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unsigned long prot, unsigned long flags,
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unsigned long fd, off_t off)
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{
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if (offset_in_page(off) != 0)
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return -EINVAL;
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return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
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}
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/*
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* Wrappers to pass the pt_regs argument.
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*/
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#define sys_execve sys_execve_wrapper
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#define sys_clone sys_clone_wrapper
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#define sys_rt_sigreturn sys_rt_sigreturn_wrapper
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#define sys_sigaltstack sys_sigaltstack_wrapper
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#include <asm/syscalls.h>
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#undef __SYSCALL
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#define __SYSCALL(nr, sym) [nr] = sym,
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/*
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* The sys_call_table array must be 4K aligned to be accessible from
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* kernel/entry.S.
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*/
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void *sys_call_table[__NR_syscalls] __aligned(4096) = {
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[0 ... __NR_syscalls - 1] = sys_ni_syscall,
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#include <asm/unistd.h>
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};
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