mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Tom Hromatka](/assets/img/avatar_default.png)
SPARC M7 and newer processors utilize ADI to version and protect memory. This driver is capable of reading/writing ADI/MCD versions from privileged user space processes. Addresses in the adi file are mapped linearly to physical memory at a ratio of 1:adi_blksz. Thus, a read (or write) of offset K in the file operates upon the ADI version at physical address K * adi_blksz. The version information is encoded as one version per byte. Intended consumers are makedumpfile and crash. Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
239 lines
4.5 KiB
C
239 lines
4.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Privileged ADI driver for sparc64
|
|
*
|
|
* Author: Tom Hromatka <tom.hromatka@oracle.com>
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/module.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/asi.h>
|
|
|
|
#define MAX_BUF_SZ PAGE_SIZE
|
|
|
|
static int adi_open(struct inode *inode, struct file *file)
|
|
{
|
|
file->f_mode |= FMODE_UNSIGNED_OFFSET;
|
|
return 0;
|
|
}
|
|
|
|
static int read_mcd_tag(unsigned long addr)
|
|
{
|
|
long err;
|
|
int ver;
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldxa [%[addr]] %[asi], %[ver]\n"
|
|
" mov 0, %[err]\n"
|
|
"2:\n"
|
|
" .section .fixup,#alloc,#execinstr\n"
|
|
" .align 4\n"
|
|
"3: sethi %%hi(2b), %%g1\n"
|
|
" jmpl %%g1 + %%lo(2b), %%g0\n"
|
|
" mov %[invalid], %[err]\n"
|
|
" .previous\n"
|
|
" .section __ex_table, \"a\"\n"
|
|
" .align 4\n"
|
|
" .word 1b, 3b\n"
|
|
" .previous\n"
|
|
: [ver] "=r" (ver), [err] "=r" (err)
|
|
: [addr] "r" (addr), [invalid] "i" (EFAULT),
|
|
[asi] "i" (ASI_MCD_REAL)
|
|
: "memory", "g1"
|
|
);
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
else
|
|
return ver;
|
|
}
|
|
|
|
static ssize_t adi_read(struct file *file, char __user *buf,
|
|
size_t count, loff_t *offp)
|
|
{
|
|
size_t ver_buf_sz, bytes_read = 0;
|
|
int ver_buf_idx = 0;
|
|
loff_t offset;
|
|
u8 *ver_buf;
|
|
ssize_t ret;
|
|
|
|
ver_buf_sz = min_t(size_t, count, MAX_BUF_SZ);
|
|
ver_buf = kmalloc(ver_buf_sz, GFP_KERNEL);
|
|
if (!ver_buf)
|
|
return -ENOMEM;
|
|
|
|
offset = (*offp) * adi_blksize();
|
|
|
|
while (bytes_read < count) {
|
|
ret = read_mcd_tag(offset);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ver_buf[ver_buf_idx] = (u8)ret;
|
|
ver_buf_idx++;
|
|
offset += adi_blksize();
|
|
|
|
if (ver_buf_idx >= ver_buf_sz) {
|
|
if (copy_to_user(buf + bytes_read, ver_buf,
|
|
ver_buf_sz)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
bytes_read += ver_buf_sz;
|
|
ver_buf_idx = 0;
|
|
|
|
ver_buf_sz = min(count - bytes_read,
|
|
(size_t)MAX_BUF_SZ);
|
|
}
|
|
}
|
|
|
|
(*offp) += bytes_read;
|
|
ret = bytes_read;
|
|
out:
|
|
kfree(ver_buf);
|
|
return ret;
|
|
}
|
|
|
|
static int set_mcd_tag(unsigned long addr, u8 ver)
|
|
{
|
|
long err;
|
|
|
|
__asm__ __volatile__(
|
|
"1: stxa %[ver], [%[addr]] %[asi]\n"
|
|
" mov 0, %[err]\n"
|
|
"2:\n"
|
|
" .section .fixup,#alloc,#execinstr\n"
|
|
" .align 4\n"
|
|
"3: sethi %%hi(2b), %%g1\n"
|
|
" jmpl %%g1 + %%lo(2b), %%g0\n"
|
|
" mov %[invalid], %[err]\n"
|
|
" .previous\n"
|
|
" .section __ex_table, \"a\"\n"
|
|
" .align 4\n"
|
|
" .word 1b, 3b\n"
|
|
" .previous\n"
|
|
: [err] "=r" (err)
|
|
: [ver] "r" (ver), [addr] "r" (addr),
|
|
[invalid] "i" (EFAULT), [asi] "i" (ASI_MCD_REAL)
|
|
: "memory", "g1"
|
|
);
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
else
|
|
return ver;
|
|
}
|
|
|
|
static ssize_t adi_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *offp)
|
|
{
|
|
size_t ver_buf_sz, bytes_written = 0;
|
|
loff_t offset;
|
|
u8 *ver_buf;
|
|
ssize_t ret;
|
|
int i;
|
|
|
|
if (count <= 0)
|
|
return -EINVAL;
|
|
|
|
ver_buf_sz = min_t(size_t, count, MAX_BUF_SZ);
|
|
ver_buf = kmalloc(ver_buf_sz, GFP_KERNEL);
|
|
if (!ver_buf)
|
|
return -ENOMEM;
|
|
|
|
offset = (*offp) * adi_blksize();
|
|
|
|
do {
|
|
if (copy_from_user(ver_buf, &buf[bytes_written],
|
|
ver_buf_sz)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < ver_buf_sz; i++) {
|
|
ret = set_mcd_tag(offset, ver_buf[i]);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
offset += adi_blksize();
|
|
}
|
|
|
|
bytes_written += ver_buf_sz;
|
|
ver_buf_sz = min(count - bytes_written, (size_t)MAX_BUF_SZ);
|
|
} while (bytes_written < count);
|
|
|
|
(*offp) += bytes_written;
|
|
ret = bytes_written;
|
|
out:
|
|
__asm__ __volatile__("membar #Sync");
|
|
kfree(ver_buf);
|
|
return ret;
|
|
}
|
|
|
|
static loff_t adi_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
loff_t ret = -EINVAL;
|
|
|
|
switch (whence) {
|
|
case SEEK_END:
|
|
case SEEK_DATA:
|
|
case SEEK_HOLE:
|
|
/* unsupported */
|
|
return -EINVAL;
|
|
case SEEK_CUR:
|
|
if (offset == 0)
|
|
return file->f_pos;
|
|
|
|
offset += file->f_pos;
|
|
break;
|
|
case SEEK_SET:
|
|
break;
|
|
}
|
|
|
|
if (offset != file->f_pos) {
|
|
file->f_pos = offset;
|
|
file->f_version = 0;
|
|
ret = offset;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations adi_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = adi_llseek,
|
|
.open = adi_open,
|
|
.read = adi_read,
|
|
.write = adi_write,
|
|
};
|
|
|
|
static struct miscdevice adi_miscdev = {
|
|
.minor = MISC_DYNAMIC_MINOR,
|
|
.name = KBUILD_MODNAME,
|
|
.fops = &adi_fops,
|
|
};
|
|
|
|
static int __init adi_init(void)
|
|
{
|
|
if (!adi_capable())
|
|
return -EPERM;
|
|
|
|
return misc_register(&adi_miscdev);
|
|
}
|
|
|
|
static void __exit adi_exit(void)
|
|
{
|
|
misc_deregister(&adi_miscdev);
|
|
}
|
|
|
|
module_init(adi_init);
|
|
module_exit(adi_exit);
|
|
|
|
MODULE_AUTHOR("Tom Hromatka <tom.hromatka@oracle.com>");
|
|
MODULE_DESCRIPTION("Privileged interface to ADI");
|
|
MODULE_VERSION("1.0");
|
|
MODULE_LICENSE("GPL v2");
|