diff options
author | 2015-08-04 12:17:53 -0700 | |
---|---|---|
committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/char/mem.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/char/mem.c')
-rw-r--r-- | kernel/drivers/char/mem.c | 872 |
1 files changed, 872 insertions, 0 deletions
diff --git a/kernel/drivers/char/mem.c b/kernel/drivers/char/mem.c new file mode 100644 index 000000000..6b1721f97 --- /dev/null +++ b/kernel/drivers/char/mem.c @@ -0,0 +1,872 @@ +/* + * linux/drivers/char/mem.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * Added devfs support. + * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu> + * Shared /dev/zero mmapping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com> + */ + +#include <linux/mm.h> +#include <linux/miscdevice.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/mman.h> +#include <linux/random.h> +#include <linux/init.h> +#include <linux/raw.h> +#include <linux/tty.h> +#include <linux/capability.h> +#include <linux/ptrace.h> +#include <linux/device.h> +#include <linux/highmem.h> +#include <linux/backing-dev.h> +#include <linux/splice.h> +#include <linux/pfn.h> +#include <linux/export.h> +#include <linux/io.h> +#include <linux/uio.h> + +#include <linux/uaccess.h> + +#ifdef CONFIG_IA64 +# include <linux/efi.h> +#endif + +#define DEVPORT_MINOR 4 + +static inline unsigned long size_inside_page(unsigned long start, + unsigned long size) +{ + unsigned long sz; + + sz = PAGE_SIZE - (start & (PAGE_SIZE - 1)); + + return min(sz, size); +} + +#ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE +static inline int valid_phys_addr_range(phys_addr_t addr, size_t count) +{ + return addr + count <= __pa(high_memory); +} + +static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) +{ + return 1; +} +#endif + +#ifdef CONFIG_STRICT_DEVMEM +static inline int range_is_allowed(unsigned long pfn, unsigned long size) +{ + u64 from = ((u64)pfn) << PAGE_SHIFT; + u64 to = from + size; + u64 cursor = from; + + while (cursor < to) { + if (!devmem_is_allowed(pfn)) { + printk(KERN_INFO + "Program %s tried to access /dev/mem between %Lx->%Lx.\n", + current->comm, from, to); + return 0; + } + cursor += PAGE_SIZE; + pfn++; + } + return 1; +} +#else +static inline int range_is_allowed(unsigned long pfn, unsigned long size) +{ + return 1; +} +#endif + +#ifndef unxlate_dev_mem_ptr +#define unxlate_dev_mem_ptr unxlate_dev_mem_ptr +void __weak unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) +{ +} +#endif + +/* + * This funcion reads the *physical* memory. The f_pos points directly to the + * memory location. + */ +static ssize_t read_mem(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + phys_addr_t p = *ppos; + ssize_t read, sz; + void *ptr; + + if (p != *ppos) + return 0; + + if (!valid_phys_addr_range(p, count)) + return -EFAULT; + read = 0; +#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED + /* we don't have page 0 mapped on sparc and m68k.. */ + if (p < PAGE_SIZE) { + sz = size_inside_page(p, count); + if (sz > 0) { + if (clear_user(buf, sz)) + return -EFAULT; + buf += sz; + p += sz; + count -= sz; + read += sz; + } + } +#endif + + while (count > 0) { + unsigned long remaining; + + sz = size_inside_page(p, count); + + if (!range_is_allowed(p >> PAGE_SHIFT, count)) + return -EPERM; + + /* + * On ia64 if a page has been mapped somewhere as uncached, then + * it must also be accessed uncached by the kernel or data + * corruption may occur. + */ + ptr = xlate_dev_mem_ptr(p); + if (!ptr) + return -EFAULT; + + remaining = copy_to_user(buf, ptr, sz); + unxlate_dev_mem_ptr(p, ptr); + if (remaining) + return -EFAULT; + + buf += sz; + p += sz; + count -= sz; + read += sz; + } + + *ppos += read; + return read; +} + +static ssize_t write_mem(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + phys_addr_t p = *ppos; + ssize_t written, sz; + unsigned long copied; + void *ptr; + + if (p != *ppos) + return -EFBIG; + + if (!valid_phys_addr_range(p, count)) + return -EFAULT; + + written = 0; + +#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED + /* we don't have page 0 mapped on sparc and m68k.. */ + if (p < PAGE_SIZE) { + sz = size_inside_page(p, count); + /* Hmm. Do something? */ + buf += sz; + p += sz; + count -= sz; + written += sz; + } +#endif + + while (count > 0) { + sz = size_inside_page(p, count); + + if (!range_is_allowed(p >> PAGE_SHIFT, sz)) + return -EPERM; + + /* + * On ia64 if a page has been mapped somewhere as uncached, then + * it must also be accessed uncached by the kernel or data + * corruption may occur. + */ + ptr = xlate_dev_mem_ptr(p); + if (!ptr) { + if (written) + break; + return -EFAULT; + } + + copied = copy_from_user(ptr, buf, sz); + unxlate_dev_mem_ptr(p, ptr); + if (copied) { + written += sz - copied; + if (written) + break; + return -EFAULT; + } + + buf += sz; + p += sz; + count -= sz; + written += sz; + } + + *ppos += written; + return written; +} + +int __weak phys_mem_access_prot_allowed(struct file *file, + unsigned long pfn, unsigned long size, pgprot_t *vma_prot) +{ + return 1; +} + +#ifndef __HAVE_PHYS_MEM_ACCESS_PROT + +/* + * Architectures vary in how they handle caching for addresses + * outside of main memory. + * + */ +#ifdef pgprot_noncached +static int uncached_access(struct file *file, phys_addr_t addr) +{ +#if defined(CONFIG_IA64) + /* + * On ia64, we ignore O_DSYNC because we cannot tolerate memory + * attribute aliases. + */ + return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); +#elif defined(CONFIG_MIPS) + { + extern int __uncached_access(struct file *file, + unsigned long addr); + + return __uncached_access(file, addr); + } +#else + /* + * Accessing memory above the top the kernel knows about or through a + * file pointer + * that was marked O_DSYNC will be done non-cached. + */ + if (file->f_flags & O_DSYNC) + return 1; + return addr >= __pa(high_memory); +#endif +} +#endif + +static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t vma_prot) +{ +#ifdef pgprot_noncached + phys_addr_t offset = pfn << PAGE_SHIFT; + + if (uncached_access(file, offset)) + return pgprot_noncached(vma_prot); +#endif + return vma_prot; +} +#endif + +#ifndef CONFIG_MMU +static unsigned long get_unmapped_area_mem(struct file *file, + unsigned long addr, + unsigned long len, + unsigned long pgoff, + unsigned long flags) +{ + if (!valid_mmap_phys_addr_range(pgoff, len)) + return (unsigned long) -EINVAL; + return pgoff << PAGE_SHIFT; +} + +/* permit direct mmap, for read, write or exec */ +static unsigned memory_mmap_capabilities(struct file *file) +{ + return NOMMU_MAP_DIRECT | + NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC; +} + +static unsigned zero_mmap_capabilities(struct file *file) +{ + return NOMMU_MAP_COPY; +} + +/* can't do an in-place private mapping if there's no MMU */ +static inline int private_mapping_ok(struct vm_area_struct *vma) +{ + return vma->vm_flags & VM_MAYSHARE; +} +#else + +static inline int private_mapping_ok(struct vm_area_struct *vma) +{ + return 1; +} +#endif + +static const struct vm_operations_struct mmap_mem_ops = { +#ifdef CONFIG_HAVE_IOREMAP_PROT + .access = generic_access_phys +#endif +}; + +static int mmap_mem(struct file *file, struct vm_area_struct *vma) +{ + size_t size = vma->vm_end - vma->vm_start; + + if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) + return -EINVAL; + + if (!private_mapping_ok(vma)) + return -ENOSYS; + + if (!range_is_allowed(vma->vm_pgoff, size)) + return -EPERM; + + if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, + &vma->vm_page_prot)) + return -EINVAL; + + vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, + size, + vma->vm_page_prot); + + vma->vm_ops = &mmap_mem_ops; + + /* Remap-pfn-range will mark the range VM_IO */ + if (remap_pfn_range(vma, + vma->vm_start, + vma->vm_pgoff, + size, + vma->vm_page_prot)) { + return -EAGAIN; + } + return 0; +} + +static int mmap_kmem(struct file *file, struct vm_area_struct *vma) +{ + unsigned long pfn; + + /* Turn a kernel-virtual address into a physical page frame */ + pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; + + /* + * RED-PEN: on some architectures there is more mapped memory than + * available in mem_map which pfn_valid checks for. Perhaps should add a + * new macro here. + * + * RED-PEN: vmalloc is not supported right now. + */ + if (!pfn_valid(pfn)) + return -EIO; + + vma->vm_pgoff = pfn; + return mmap_mem(file, vma); +} + +/* + * This function reads the *virtual* memory as seen by the kernel. + */ +static ssize_t read_kmem(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long p = *ppos; + ssize_t low_count, read, sz; + char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ + int err = 0; + + read = 0; + if (p < (unsigned long) high_memory) { + low_count = count; + if (count > (unsigned long)high_memory - p) + low_count = (unsigned long)high_memory - p; + +#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED + /* we don't have page 0 mapped on sparc and m68k.. */ + if (p < PAGE_SIZE && low_count > 0) { + sz = size_inside_page(p, low_count); + if (clear_user(buf, sz)) + return -EFAULT; + buf += sz; + p += sz; + read += sz; + low_count -= sz; + count -= sz; + } +#endif + while (low_count > 0) { + sz = size_inside_page(p, low_count); + + /* + * On ia64 if a page has been mapped somewhere as + * uncached, then it must also be accessed uncached + * by the kernel or data corruption may occur + */ + kbuf = xlate_dev_kmem_ptr((void *)p); + + if (copy_to_user(buf, kbuf, sz)) + return -EFAULT; + buf += sz; + p += sz; + read += sz; + low_count -= sz; + count -= sz; + } + } + + if (count > 0) { + kbuf = (char *)__get_free_page(GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + while (count > 0) { + sz = size_inside_page(p, count); + if (!is_vmalloc_or_module_addr((void *)p)) { + err = -ENXIO; + break; + } + sz = vread(kbuf, (char *)p, sz); + if (!sz) + break; + if (copy_to_user(buf, kbuf, sz)) { + err = -EFAULT; + break; + } + count -= sz; + buf += sz; + read += sz; + p += sz; + } + free_page((unsigned long)kbuf); + } + *ppos = p; + return read ? read : err; +} + + +static ssize_t do_write_kmem(unsigned long p, const char __user *buf, + size_t count, loff_t *ppos) +{ + ssize_t written, sz; + unsigned long copied; + + written = 0; +#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED + /* we don't have page 0 mapped on sparc and m68k.. */ + if (p < PAGE_SIZE) { + sz = size_inside_page(p, count); + /* Hmm. Do something? */ + buf += sz; + p += sz; + count -= sz; + written += sz; + } +#endif + + while (count > 0) { + void *ptr; + + sz = size_inside_page(p, count); + + /* + * On ia64 if a page has been mapped somewhere as uncached, then + * it must also be accessed uncached by the kernel or data + * corruption may occur. + */ + ptr = xlate_dev_kmem_ptr((void *)p); + + copied = copy_from_user(ptr, buf, sz); + if (copied) { + written += sz - copied; + if (written) + break; + return -EFAULT; + } + buf += sz; + p += sz; + count -= sz; + written += sz; + } + + *ppos += written; + return written; +} + +/* + * This function writes to the *virtual* memory as seen by the kernel. + */ +static ssize_t write_kmem(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long p = *ppos; + ssize_t wrote = 0; + ssize_t virtr = 0; + char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ + int err = 0; + + if (p < (unsigned long) high_memory) { + unsigned long to_write = min_t(unsigned long, count, + (unsigned long)high_memory - p); + wrote = do_write_kmem(p, buf, to_write, ppos); + if (wrote != to_write) + return wrote; + p += wrote; + buf += wrote; + count -= wrote; + } + + if (count > 0) { + kbuf = (char *)__get_free_page(GFP_KERNEL); + if (!kbuf) + return wrote ? wrote : -ENOMEM; + while (count > 0) { + unsigned long sz = size_inside_page(p, count); + unsigned long n; + + if (!is_vmalloc_or_module_addr((void *)p)) { + err = -ENXIO; + break; + } + n = copy_from_user(kbuf, buf, sz); + if (n) { + err = -EFAULT; + break; + } + vwrite(kbuf, (char *)p, sz); + count -= sz; + buf += sz; + virtr += sz; + p += sz; + } + free_page((unsigned long)kbuf); + } + + *ppos = p; + return virtr + wrote ? : err; +} + +static ssize_t read_port(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long i = *ppos; + char __user *tmp = buf; + + if (!access_ok(VERIFY_WRITE, buf, count)) + return -EFAULT; + while (count-- > 0 && i < 65536) { + if (__put_user(inb(i), tmp) < 0) + return -EFAULT; + i++; + tmp++; + } + *ppos = i; + return tmp-buf; +} + +static ssize_t write_port(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long i = *ppos; + const char __user *tmp = buf; + + if (!access_ok(VERIFY_READ, buf, count)) + return -EFAULT; + while (count-- > 0 && i < 65536) { + char c; + + if (__get_user(c, tmp)) { + if (tmp > buf) + break; + return -EFAULT; + } + outb(c, i); + i++; + tmp++; + } + *ppos = i; + return tmp-buf; +} + +static ssize_t read_null(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + return 0; +} + +static ssize_t write_null(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return count; +} + +static ssize_t read_iter_null(struct kiocb *iocb, struct iov_iter *to) +{ + return 0; +} + +static ssize_t write_iter_null(struct kiocb *iocb, struct iov_iter *from) +{ + size_t count = iov_iter_count(from); + iov_iter_advance(from, count); + return count; +} + +static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, + struct splice_desc *sd) +{ + return sd->len; +} + +static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out, + loff_t *ppos, size_t len, unsigned int flags) +{ + return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); +} + +static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter) +{ + size_t written = 0; + + while (iov_iter_count(iter)) { + size_t chunk = iov_iter_count(iter), n; + + if (chunk > PAGE_SIZE) + chunk = PAGE_SIZE; /* Just for latency reasons */ + n = iov_iter_zero(chunk, iter); + if (!n && iov_iter_count(iter)) + return written ? written : -EFAULT; + written += n; + if (signal_pending(current)) + return written ? written : -ERESTARTSYS; + cond_resched(); + } + return written; +} + +static int mmap_zero(struct file *file, struct vm_area_struct *vma) +{ +#ifndef CONFIG_MMU + return -ENOSYS; +#endif + if (vma->vm_flags & VM_SHARED) + return shmem_zero_setup(vma); + return 0; +} + +static ssize_t write_full(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + return -ENOSPC; +} + +/* + * Special lseek() function for /dev/null and /dev/zero. Most notably, you + * can fopen() both devices with "a" now. This was previously impossible. + * -- SRB. + */ +static loff_t null_lseek(struct file *file, loff_t offset, int orig) +{ + return file->f_pos = 0; +} + +/* + * The memory devices use the full 32/64 bits of the offset, and so we cannot + * check against negative addresses: they are ok. The return value is weird, + * though, in that case (0). + * + * also note that seeking relative to the "end of file" isn't supported: + * it has no meaning, so it returns -EINVAL. + */ +static loff_t memory_lseek(struct file *file, loff_t offset, int orig) +{ + loff_t ret; + + mutex_lock(&file_inode(file)->i_mutex); + switch (orig) { + case SEEK_CUR: + offset += file->f_pos; + case SEEK_SET: + /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */ + if (IS_ERR_VALUE((unsigned long long)offset)) { + ret = -EOVERFLOW; + break; + } + file->f_pos = offset; + ret = file->f_pos; + force_successful_syscall_return(); + break; + default: + ret = -EINVAL; + } + mutex_unlock(&file_inode(file)->i_mutex); + return ret; +} + +static int open_port(struct inode *inode, struct file *filp) +{ + return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; +} + +#define zero_lseek null_lseek +#define full_lseek null_lseek +#define write_zero write_null +#define write_iter_zero write_iter_null +#define open_mem open_port +#define open_kmem open_mem + +static const struct file_operations __maybe_unused mem_fops = { + .llseek = memory_lseek, + .read = read_mem, + .write = write_mem, + .mmap = mmap_mem, + .open = open_mem, +#ifndef CONFIG_MMU + .get_unmapped_area = get_unmapped_area_mem, + .mmap_capabilities = memory_mmap_capabilities, +#endif +}; + +static const struct file_operations __maybe_unused kmem_fops = { + .llseek = memory_lseek, + .read = read_kmem, + .write = write_kmem, + .mmap = mmap_kmem, + .open = open_kmem, +#ifndef CONFIG_MMU + .get_unmapped_area = get_unmapped_area_mem, + .mmap_capabilities = memory_mmap_capabilities, +#endif +}; + +static const struct file_operations null_fops = { + .llseek = null_lseek, + .read = read_null, + .write = write_null, + .read_iter = read_iter_null, + .write_iter = write_iter_null, + .splice_write = splice_write_null, +}; + +static const struct file_operations __maybe_unused port_fops = { + .llseek = memory_lseek, + .read = read_port, + .write = write_port, + .open = open_port, +}; + +static const struct file_operations zero_fops = { + .llseek = zero_lseek, + .write = write_zero, + .read_iter = read_iter_zero, + .write_iter = write_iter_zero, + .mmap = mmap_zero, +#ifndef CONFIG_MMU + .mmap_capabilities = zero_mmap_capabilities, +#endif +}; + +static const struct file_operations full_fops = { + .llseek = full_lseek, + .read_iter = read_iter_zero, + .write = write_full, +}; + +static const struct memdev { + const char *name; + umode_t mode; + const struct file_operations *fops; + fmode_t fmode; +} devlist[] = { +#ifdef CONFIG_DEVMEM + [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET }, +#endif +#ifdef CONFIG_DEVKMEM + [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET }, +#endif + [3] = { "null", 0666, &null_fops, 0 }, +#ifdef CONFIG_DEVPORT + [4] = { "port", 0, &port_fops, 0 }, +#endif + [5] = { "zero", 0666, &zero_fops, 0 }, + [7] = { "full", 0666, &full_fops, 0 }, + [8] = { "random", 0666, &random_fops, 0 }, + [9] = { "urandom", 0666, &urandom_fops, 0 }, +#ifdef CONFIG_PRINTK + [11] = { "kmsg", 0644, &kmsg_fops, 0 }, +#endif +}; + +static int memory_open(struct inode *inode, struct file *filp) +{ + int minor; + const struct memdev *dev; + + minor = iminor(inode); + if (minor >= ARRAY_SIZE(devlist)) + return -ENXIO; + + dev = &devlist[minor]; + if (!dev->fops) + return -ENXIO; + + filp->f_op = dev->fops; + filp->f_mode |= dev->fmode; + + if (dev->fops->open) + return dev->fops->open(inode, filp); + + return 0; +} + +static const struct file_operations memory_fops = { + .open = memory_open, + .llseek = noop_llseek, +}; + +static char *mem_devnode(struct device *dev, umode_t *mode) +{ + if (mode && devlist[MINOR(dev->devt)].mode) + *mode = devlist[MINOR(dev->devt)].mode; + return NULL; +} + +static struct class *mem_class; + +static int __init chr_dev_init(void) +{ + int minor; + + if (register_chrdev(MEM_MAJOR, "mem", &memory_fops)) + printk("unable to get major %d for memory devs\n", MEM_MAJOR); + + mem_class = class_create(THIS_MODULE, "mem"); + if (IS_ERR(mem_class)) + return PTR_ERR(mem_class); + + mem_class->devnode = mem_devnode; + for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) { + if (!devlist[minor].name) + continue; + + /* + * Create /dev/port? + */ + if ((minor == DEVPORT_MINOR) && !arch_has_dev_port()) + continue; + + device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor), + NULL, devlist[minor].name); + } + + return tty_init(); +} + +fs_initcall(chr_dev_init); |