linux/drivers/pci/pcie/aer/aer_inject.c

570 lines
14 KiB
C
Raw Normal View 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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/stddef.h>
#include <linux/device.h>
#include "aerdrv.h"
/* Override the existing corrected and uncorrected error masks */
static bool aer_mask_override;
module_param(aer_mask_override, bool, 0);
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;
u32 domain;
};
struct aer_error {
struct list_head list;
u32 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, u32 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(u32 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(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;
spin_lock_irqsave(&inject_lock, flags);
bus_ops = list_first_entry_or_null(&pci_bus_ops_list,
struct pci_bus_ops, list);
if (bus_ops)
list_del(&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 aer_inj_read_config(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;
struct pci_ops *my_ops;
int domain;
int rv;
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(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);
/*
* pci_lock must already be held, so we can directly
* manipulate bus->ops. Many config access functions,
* including pci_generic_config_read() require the original
* bus->ops be installed to function, so temporarily put them
* back.
*/
my_ops = bus->ops;
bus->ops = ops;
rv = ops->read(bus, devfn, where, size, val);
bus->ops = my_ops;
spin_unlock_irqrestore(&inject_lock, flags);
return rv;
}
static int aer_inj_write_config(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;
struct pci_ops *my_ops;
int domain;
int rv;
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(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);
/*
* pci_lock must already be held, so we can directly
* manipulate bus->ops. Many config access functions,
* including pci_generic_config_write() require the original
* bus->ops be installed to function, so temporarily put them
* back.
*/
my_ops = bus->ops;
bus->ops = ops;
rv = ops->write(bus, devfn, where, size, val);
bus->ops = my_ops;
spin_unlock_irqrestore(&inject_lock, flags);
return rv;
}
static struct pci_ops aer_inj_pci_ops = {
.read = aer_inj_read_config,
.write = aer_inj_write_config,
};
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, &aer_inj_pci_ops);
spin_lock_irqsave(&inject_lock, flags);
if (ops == &aer_inj_pci_ops)
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 (pci_pcie_type(dev) == 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, cor_mask_orig = 0, uncor_mask_orig = 0;
int ret = 0;
dev = pci_get_domain_bus_and_slot(einj->domain, einj->bus, devfn);
if (!dev)
return -ENODEV;
rpdev = pcie_find_root_port(dev);
if (!rpdev) {
dev_err(&dev->dev, "aer_inject: Root port not found\n");
ret = -ENODEV;
goto out_put;
}
pos_cap_err = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
if (!pos_cap_err) {
dev_err(&dev->dev, "aer_inject: Device doesn't support AER\n");
ret = -EPROTONOSUPPORT;
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) {
dev_err(&rpdev->dev,
"aer_inject: Root port doesn't support AER\n");
ret = -EPROTONOSUPPORT;
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;
}
if (aer_mask_override) {
cor_mask_orig = cor_mask;
cor_mask &= !(einj->cor_status);
pci_write_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK,
cor_mask);
uncor_mask_orig = uncor_mask;
uncor_mask &= !(einj->uncor_status);
pci_write_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
uncor_mask);
}
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 (!aer_mask_override && einj->cor_status &&
!(einj->cor_status & ~cor_mask)) {
ret = -EINVAL;
dev_warn(&dev->dev,
"aer_inject: The correctable error(s) is masked by device\n");
spin_unlock_irqrestore(&inject_lock, flags);
goto out_put;
}
if (!aer_mask_override && einj->uncor_status &&
!(einj->uncor_status & ~uncor_mask)) {
ret = -EINVAL;
dev_warn(&dev->dev,
"aer_inject: 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);
if (aer_mask_override) {
pci_write_config_dword(dev, pos_cap_err + PCI_ERR_COR_MASK,
cor_mask_orig);
pci_write_config_dword(dev, pos_cap_err + PCI_ERR_UNCOR_MASK,
uncor_mask_orig);
}
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;
PCI: AER: fix aer inject result in kernel oops If the BIOS does not export _OSC to allow OS take over the PCIe AER, the pcie aer driver will not initialize the aer service. However, the aer_inject driver does not check this scenario, which results in a kernel oops when injecting an aer error into OS. For example: BUG: unable to handle kernel NULL pointer dereference at 0000000000000350 IP: [<ffffffff812e08f7>] _spin_lock_irqsave+0xc/0x23 PGD 155c41067 PUD 157fe0067 PMD 0 Oops: 0002 [#1] SMP Pid: 5119, comm: aer-inject Not tainted 2.6.32-rc8-mce #2 RIP: 0010:[<ffffffff812e08f7>] [<ffffffff812e08f7>] _spin_lock_irqsave+0xc/0x23 RSP: 0018:ffff880157f81e28 EFLAGS: 00010096 RAX: 0000000000000296 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 0000000000010000 RSI: 0000000000000246 RDI: 0000000000000350 RBP: ffff880157f81e28 R08: 0000000000000004 R09: ffff880157f81dac R10: ffff88015a666f60 R11: ffff88015a666f40 R12: ffff88015758cc00 R13: 0000000000000350 R14: 0000000000000000 R15: 0000000000000100 FS: 00007f4d4a66e6f0(0000) GS:ffff8800282e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000350 CR3: 000000015661a000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process aer-inject (pid: 5119, threadinfo ffff880157f80000, task ffff8801585f4340) Stack: ffff880157f81e78 ffffffff811b1615 ffff880157f81e78 ffffffff81222823 Call Trace: [<ffffffff811b1615>] aer_irq+0x38/0x117 [<ffffffff81222823>] ? device_for_each_child+0x5f/0x6f [<ffffffffa00967bf>] aer_inject_write+0x409/0x45e [aer_inject] [<ffffffff810eb80e>] vfs_write+0xae/0x16a [<ffffffff810eb98e>] sys_write+0x47/0x6e [<ffffffff8100ba2b>] system_call_fastpath+0x16/0x1b RIP [<ffffffff812e08f7>] _spin_lock_irqsave+0xc/0x23 RSP <ffff880157f81e28> CR2: 0000000000000350 So check the _OSC before assuming that AER is available to the OS. Signed-off-by: Youquan, Song <youquan.song@intel.com> Acked-by: Ying, Huang <ying.huang@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-12-12 07:42:35 +08:00
if (find_aer_device(rpdev, &edev)) {
if (!get_service_data(edev)) {
dev_warn(&edev->device,
"aer_inject: AER service is not initialized\n");
ret = -EPROTONOSUPPORT;
PCI: AER: fix aer inject result in kernel oops If the BIOS does not export _OSC to allow OS take over the PCIe AER, the pcie aer driver will not initialize the aer service. However, the aer_inject driver does not check this scenario, which results in a kernel oops when injecting an aer error into OS. For example: BUG: unable to handle kernel NULL pointer dereference at 0000000000000350 IP: [<ffffffff812e08f7>] _spin_lock_irqsave+0xc/0x23 PGD 155c41067 PUD 157fe0067 PMD 0 Oops: 0002 [#1] SMP Pid: 5119, comm: aer-inject Not tainted 2.6.32-rc8-mce #2 RIP: 0010:[<ffffffff812e08f7>] [<ffffffff812e08f7>] _spin_lock_irqsave+0xc/0x23 RSP: 0018:ffff880157f81e28 EFLAGS: 00010096 RAX: 0000000000000296 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 0000000000010000 RSI: 0000000000000246 RDI: 0000000000000350 RBP: ffff880157f81e28 R08: 0000000000000004 R09: ffff880157f81dac R10: ffff88015a666f60 R11: ffff88015a666f40 R12: ffff88015758cc00 R13: 0000000000000350 R14: 0000000000000000 R15: 0000000000000100 FS: 00007f4d4a66e6f0(0000) GS:ffff8800282e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000350 CR3: 000000015661a000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process aer-inject (pid: 5119, threadinfo ffff880157f80000, task ffff8801585f4340) Stack: ffff880157f81e78 ffffffff811b1615 ffff880157f81e78 ffffffff81222823 Call Trace: [<ffffffff811b1615>] aer_irq+0x38/0x117 [<ffffffff81222823>] ? device_for_each_child+0x5f/0x6f [<ffffffffa00967bf>] aer_inject_write+0x409/0x45e [aer_inject] [<ffffffff810eb80e>] vfs_write+0xae/0x16a [<ffffffff810eb98e>] sys_write+0x47/0x6e [<ffffffff8100ba2b>] system_call_fastpath+0x16/0x1b RIP [<ffffffff812e08f7>] _spin_lock_irqsave+0xc/0x23 RSP <ffff880157f81e28> CR2: 0000000000000350 So check the _OSC before assuming that AER is available to the OS. Signed-off-by: Youquan, Song <youquan.song@intel.com> Acked-by: Ying, Huang <ying.huang@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-12-12 07:42:35 +08:00
goto out_put;
}
aer_irq(-1, edev);
} else {
dev_err(&rpdev->dev, "aer_inject: AER device not found\n");
ret = -ENODEV;
}
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: 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>
2010-08-16 00:52:59 +08:00
.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");