davidlt/kernel-ark
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
e9f29c9a56
kernel-ark/drivers/pci/pcie/aer/aer_inject.c
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop 
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00

515 lines
12 KiB
C
Raw Blame History

/*
* PCIe AER software error injection support.
*
* Debuging PCIe AER code is quite difficult because it is hard to
* trigger various real hardware errors. Software based error
* injection can fake almost all kinds of errors with the help of a
* user space helper tool aer-inject, which can be gotten from:
* http://www.kernel.org/pub/linux/utils/pci/aer-inject/
*
* Copyright 2009 Intel Corporation.
* Huang Ying <ying.huang@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2
* of the License.
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/stddef.h>
#include "aerdrv.h"
struct aer_error_inj {
u8 bus;
u8 dev;
u8 fn;
u32 uncor_status;
u32 cor_status;
u32 header_log0;
u32 header_log1;
u32 header_log2;
u32 header_log3;
u16 domain;
};
struct aer_error {
struct list_head list;
u16 domain;
unsigned int bus;
unsigned int devfn;
int pos_cap_err;
u32 uncor_status;
u32 cor_status;
u32 header_log0;
u32 header_log1;
u32 header_log2;
u32 header_log3;
u32 root_status;
u32 source_id;
};
struct pci_bus_ops {
struct list_head list;
struct pci_bus *bus;
struct pci_ops *ops;
};
static LIST_HEAD(einjected);
static LIST_HEAD(pci_bus_ops_list);
/* Protect einjected and pci_bus_ops_list */
static DEFINE_SPINLOCK(inject_lock);
static void aer_error_init(struct aer_error *err, u16 domain,
unsigned int bus, unsigned int devfn,
int pos_cap_err)
{
INIT_LIST_HEAD(&err->list);
err->domain = domain;
err->bus = bus;
err->devfn = devfn;
err->pos_cap_err = pos_cap_err;
}
/* inject_lock must be held before calling */
static struct aer_error *__find_aer_error(u16 domain, unsigned int bus,
unsigned int devfn)
{
struct aer_error *err;
list_for_each_entry(err, &einjected, list) {
if (domain == err->domain &&
bus == err->bus &&
devfn == err->devfn)
return err;
}
return NULL;
}
/* inject_lock must be held before calling */
static struct aer_error *__find_aer_error_by_dev(struct pci_dev *dev)
{
int domain = pci_domain_nr(dev->bus);
if (domain < 0)
return NULL;
return __find_aer_error((u16)domain, dev->bus->number, dev->devfn);
}
/* inject_lock must be held before calling */
static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus)
{
struct pci_bus_ops *bus_ops;
list_for_each_entry(bus_ops, &pci_bus_ops_list, list) {
if (bus_ops->bus == bus)
return bus_ops->ops;
}
return NULL;
}
static struct pci_bus_ops *pci_bus_ops_pop(void)
{
unsigned long flags;
struct pci_bus_ops *bus_ops = NULL;
spin_lock_irqsave(&inject_lock, flags);
if (list_empty(&pci_bus_ops_list))
bus_ops = NULL;
else {
struct list_head *lh = pci_bus_ops_list.next;
list_del(lh);
bus_ops = list_entry(lh, struct pci_bus_ops, list);
}
spin_unlock_irqrestore(&inject_lock, flags);
return bus_ops;
}
static u32 *find_pci_config_dword(struct aer_error *err, int where,
int *prw1cs)
{
int rw1cs = 0;
u32 *target = NULL;
if (err->pos_cap_err == -1)
return NULL;
switch (where - err->pos_cap_err) {
case PCI_ERR_UNCOR_STATUS:
target = &err->uncor_status;
rw1cs = 1;
break;
case PCI_ERR_COR_STATUS:
target = &err->cor_status;
rw1cs = 1;
break;
case PCI_ERR_HEADER_LOG:
target = &err->header_log0;
break;
case PCI_ERR_HEADER_LOG+4:
target = &err->header_log1;
break;
case PCI_ERR_HEADER_LOG+8:
target = &err->header_log2;
break;
case PCI_ERR_HEADER_LOG+12:
target = &err->header_log3;
break;
case PCI_ERR_ROOT_STATUS:
target = &err->root_status;
rw1cs = 1;
break;
case PCI_ERR_ROOT_ERR_SRC:
target = &err->source_id;
break;
}
if (prw1cs)
*prw1cs = rw1cs;
return target;
}
static int pci_read_aer(struct pci_bus *bus, unsigned int devfn, int where,
int size, u32 *val)
{
u32 *sim;
struct aer_error *err;
unsigned long flags;
struct pci_ops *ops;
int domain;
spin_lock_irqsave(&inject_lock, flags);
if (size != sizeof(u32))
goto out;
domain = pci_domain_nr(bus);
if (domain < 0)
goto out;
err = __find_aer_error((u16)domain, bus->number, devfn);
if (!err)
goto out;
sim = find_pci_config_dword(err, where, NULL);
if (sim) {
*val = *sim;
spin_unlock_irqrestore(&inject_lock, flags);
return 0;
}
out:
ops = __find_pci_bus_ops(bus);
spin_unlock_irqrestore(&inject_lock, flags);
return ops->read(bus, devfn, where, size, val);
}
int pci_write_aer(struct pci_bus *bus, unsigned int devfn, int where, int size,
u32 val)
{
u32 *sim;
struct aer_error *err;
unsigned long flags;
int rw1cs;
struct pci_ops *ops;
int domain;
spin_lock_irqsave(&inject_lock, flags);
if (size != sizeof(u32))
goto out;
domain = pci_domain_nr(bus);
if (domain < 0)
goto out;
err = __find_aer_error((u16)domain, bus->number, devfn);
if (!err)
goto out;
sim = find_pci_config_dword(err, where, &rw1cs);
if (sim) {
if (rw1cs)
*sim ^= val;
else
*sim = val;
spin_unlock_irqrestore(&inject_lock, flags);
return 0;
}
out:
ops = __find_pci_bus_ops(bus);
spin_unlock_irqrestore(&inject_lock, flags);
return ops->write(bus, devfn, where, size, val);
}
static struct pci_ops pci_ops_aer = {
.read = pci_read_aer,
.write = pci_write_aer,
};
static void pci_bus_ops_init(struct pci_bus_ops *bus_ops,
struct pci_bus *bus,
struct pci_ops *ops)
{
INIT_LIST_HEAD(&bus_ops->list);
bus_ops->bus = bus;
bus_ops->ops = ops;
}
static int pci_bus_set_aer_ops(struct pci_bus *bus)
{
struct pci_ops *ops;
struct pci_bus_ops *bus_ops;
unsigned long flags;
bus_ops = kmalloc(sizeof(*bus_ops), GFP_KERNEL);
if (!bus_ops)
return -ENOMEM;
ops = pci_bus_set_ops(bus, &pci_ops_aer);
spin_lock_irqsave(&inject_lock, flags);
if (ops == &pci_ops_aer)
goto out;
pci_bus_ops_init(bus_ops, bus, ops);
list_add(&bus_ops->list, &pci_bus_ops_list);
bus_ops = NULL;
out:
spin_unlock_irqrestore(&inject_lock, flags);
kfree(bus_ops);
return 0;
}
static struct pci_dev *pcie_find_root_port(struct pci_dev *dev)
{
while (1) {
if (!pci_is_pcie(dev))
break;
if (dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT)
return dev;
if (!dev->bus->self)
break;
dev = dev->bus->self;
}
return NULL;
}
static int find_aer_device_iter(struct device *device, void *data)
{
struct pcie_device **result = data;
struct pcie_device *pcie_dev;
if (device->bus == &pcie_port_bus_type) {
pcie_dev = to_pcie_device(device);
if (pcie_dev->service & PCIE_PORT_SERVICE_AER) {
*result = pcie_dev;
return 1;
}
}
return 0;
}
static int find_aer_device(struct pci_dev *dev, struct pcie_device **result)
{
return device_for_each_child(&dev->dev, result, find_aer_device_iter);
}
static int aer_inject(struct aer_error_inj *einj)
{
struct aer_error *err, *rperr;
struct aer_error *err_alloc = NULL, *rperr_alloc = NULL;
struct pci_dev *dev, *rpdev;
struct pcie_device *edev;
unsigned long flags;
unsigned int devfn = PCI_DEVFN(einj->dev, einj->fn);
int pos_cap_err, rp_pos_cap_err;
u32 sever, cor_mask, uncor_mask;
int ret = 0;
dev = pci_get_domain_bus_and_slot((int)einj->domain, einj->bus, devfn);
if (!dev)
return -ENODEV;
rpdev = pcie_find_root_port(dev);
if (!rpdev) {
ret = -ENOTTY;
goto out_put;
}
pos_cap_err = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
if (!pos_cap_err) {
ret = -ENOTTY;
goto out_put;
}
pci_read_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_SEVER, &sever);
pci_read_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK, &cor_mask);
pci_read_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
&uncor_mask);
rp_pos_cap_err = pci_find_ext_capability(rpdev, PCI_EXT_CAP_ID_ERR);
if (!rp_pos_cap_err) {
ret = -ENOTTY;
goto out_put;
}
err_alloc = kzalloc(sizeof(struct aer_error), GFP_KERNEL);
if (!err_alloc) {
ret = -ENOMEM;
goto out_put;
}
rperr_alloc = kzalloc(sizeof(struct aer_error), GFP_KERNEL);
if (!rperr_alloc) {
ret = -ENOMEM;
goto out_put;
}
spin_lock_irqsave(&inject_lock, flags);
err = __find_aer_error_by_dev(dev);
if (!err) {
err = err_alloc;
err_alloc = NULL;
aer_error_init(err, einj->domain, einj->bus, devfn,
pos_cap_err);
list_add(&err->list, &einjected);
}
err->uncor_status |= einj->uncor_status;
err->cor_status |= einj->cor_status;
err->header_log0 = einj->header_log0;
err->header_log1 = einj->header_log1;
err->header_log2 = einj->header_log2;
err->header_log3 = einj->header_log3;
if (einj->cor_status && !(einj->cor_status & ~cor_mask)) {
ret = -EINVAL;
printk(KERN_WARNING "The correctable error(s) is masked "
"by device\n");
spin_unlock_irqrestore(&inject_lock, flags);
goto out_put;
}
if (einj->uncor_status && !(einj->uncor_status & ~uncor_mask)) {
ret = -EINVAL;
printk(KERN_WARNING "The uncorrectable error(s) is masked "
"by device\n");
spin_unlock_irqrestore(&inject_lock, flags);
goto out_put;
}
rperr = __find_aer_error_by_dev(rpdev);
if (!rperr) {
rperr = rperr_alloc;
rperr_alloc = NULL;
aer_error_init(rperr, pci_domain_nr(rpdev->bus),
rpdev->bus->number, rpdev->devfn,
rp_pos_cap_err);
list_add(&rperr->list, &einjected);
}
if (einj->cor_status) {
if (rperr->root_status & PCI_ERR_ROOT_COR_RCV)
rperr->root_status |= PCI_ERR_ROOT_MULTI_COR_RCV;
else
rperr->root_status |= PCI_ERR_ROOT_COR_RCV;
rperr->source_id &= 0xffff0000;
rperr->source_id |= (einj->bus << 8) | devfn;
}
if (einj->uncor_status) {
if (rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV)
rperr->root_status |= PCI_ERR_ROOT_MULTI_UNCOR_RCV;
if (sever & einj->uncor_status) {
rperr->root_status |= PCI_ERR_ROOT_FATAL_RCV;
if (!(rperr->root_status & PCI_ERR_ROOT_UNCOR_RCV))
rperr->root_status |= PCI_ERR_ROOT_FIRST_FATAL;
} else
rperr->root_status |= PCI_ERR_ROOT_NONFATAL_RCV;
rperr->root_status |= PCI_ERR_ROOT_UNCOR_RCV;
rperr->source_id &= 0x0000ffff;
rperr->source_id |= ((einj->bus << 8) | devfn) << 16;
}
spin_unlock_irqrestore(&inject_lock, flags);
ret = pci_bus_set_aer_ops(dev->bus);
if (ret)
goto out_put;
ret = pci_bus_set_aer_ops(rpdev->bus);
if (ret)
goto out_put;
if (find_aer_device(rpdev, &edev)) {
if (!get_service_data(edev)) {
printk(KERN_WARNING "AER service is not initialized\n");
ret = -EINVAL;
goto out_put;
}
aer_irq(-1, edev);
}
else
ret = -EINVAL;
out_put:
kfree(err_alloc);
kfree(rperr_alloc);
pci_dev_put(dev);
return ret;
}
static ssize_t aer_inject_write(struct file *filp, const char __user *ubuf,
size_t usize, loff_t *off)
{
struct aer_error_inj einj;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (usize < offsetof(struct aer_error_inj, domain) ||
usize > sizeof(einj))
return -EINVAL;
memset(&einj, 0, sizeof(einj));
if (copy_from_user(&einj, ubuf, usize))
return -EFAULT;
ret = aer_inject(&einj);
return ret ? ret : usize;
}
static const struct file_operations aer_inject_fops = {
.write = aer_inject_write,
.owner = THIS_MODULE,
.llseek = noop_llseek,
};
static struct miscdevice aer_inject_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "aer_inject",
.fops = &aer_inject_fops,
};
static int __init aer_inject_init(void)
{
return misc_register(&aer_inject_device);
}
static void __exit aer_inject_exit(void)
{
struct aer_error *err, *err_next;
unsigned long flags;
struct pci_bus_ops *bus_ops;
misc_deregister(&aer_inject_device);
while ((bus_ops = pci_bus_ops_pop())) {
pci_bus_set_ops(bus_ops->bus, bus_ops->ops);
kfree(bus_ops);
}
spin_lock_irqsave(&inject_lock, flags);
list_for_each_entry_safe(err, err_next, &einjected, list) {
list_del(&err->list);
kfree(err);
}
spin_unlock_irqrestore(&inject_lock, flags);
}
module_init(aer_inject_init);
module_exit(aer_inject_exit);
MODULE_DESCRIPTION("PCIe AER software error injector");
MODULE_LICENSE("GPL");
Reference in New Issue View Git Blame Copy Permalink