mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 13:41:51 +00:00
f0483044c1
Make sure that even in error situations we do not use copy_to_user on uninitialized kernel memory. Cc: stable@vger.kernel.org # 3.19+ Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
115 lines
2.4 KiB
C
115 lines
2.4 KiB
C
/*
|
|
* Access to PCI I/O memory from user space programs.
|
|
*
|
|
* Copyright IBM Corp. 2014
|
|
* Author(s): Alexey Ishchuk <aishchuk@linux.vnet.ibm.com>
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/init.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/pci.h>
|
|
|
|
static long get_pfn(unsigned long user_addr, unsigned long access,
|
|
unsigned long *pfn)
|
|
{
|
|
struct vm_area_struct *vma;
|
|
long ret;
|
|
|
|
down_read(¤t->mm->mmap_sem);
|
|
ret = -EINVAL;
|
|
vma = find_vma(current->mm, user_addr);
|
|
if (!vma)
|
|
goto out;
|
|
ret = -EACCES;
|
|
if (!(vma->vm_flags & access))
|
|
goto out;
|
|
ret = follow_pfn(vma, user_addr, pfn);
|
|
out:
|
|
up_read(¤t->mm->mmap_sem);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr,
|
|
const void __user *, user_buffer, size_t, length)
|
|
{
|
|
u8 local_buf[64];
|
|
void __iomem *io_addr;
|
|
void *buf;
|
|
unsigned long pfn;
|
|
long ret;
|
|
|
|
if (!zpci_is_enabled())
|
|
return -ENODEV;
|
|
|
|
if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
|
|
return -EINVAL;
|
|
if (length > 64) {
|
|
buf = kmalloc(length, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
} else
|
|
buf = local_buf;
|
|
|
|
ret = get_pfn(mmio_addr, VM_WRITE, &pfn);
|
|
if (ret)
|
|
goto out;
|
|
io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK));
|
|
|
|
ret = -EFAULT;
|
|
if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE)
|
|
goto out;
|
|
|
|
if (copy_from_user(buf, user_buffer, length))
|
|
goto out;
|
|
|
|
ret = zpci_memcpy_toio(io_addr, buf, length);
|
|
out:
|
|
if (buf != local_buf)
|
|
kfree(buf);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr,
|
|
void __user *, user_buffer, size_t, length)
|
|
{
|
|
u8 local_buf[64];
|
|
void __iomem *io_addr;
|
|
void *buf;
|
|
unsigned long pfn;
|
|
long ret;
|
|
|
|
if (!zpci_is_enabled())
|
|
return -ENODEV;
|
|
|
|
if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length)
|
|
return -EINVAL;
|
|
if (length > 64) {
|
|
buf = kmalloc(length, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
} else
|
|
buf = local_buf;
|
|
|
|
ret = get_pfn(mmio_addr, VM_READ, &pfn);
|
|
if (ret)
|
|
goto out;
|
|
io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK));
|
|
|
|
if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
ret = zpci_memcpy_fromio(buf, io_addr, length);
|
|
if (ret)
|
|
goto out;
|
|
if (copy_to_user(user_buffer, buf, length))
|
|
ret = -EFAULT;
|
|
|
|
out:
|
|
if (buf != local_buf)
|
|
kfree(buf);
|
|
return ret;
|
|
}
|