mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-06 02:50:43 +00:00
![Gustavo A. R. Silva](/assets/img/avatar_default.png)
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293
("cxgb3/l2t: Fix undefined behaviour")
Link: https://lkml.kernel.org/r/20200221150612.GA9717@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
200 lines
4.2 KiB
C
200 lines
4.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* PCI I/O adapter configuration related functions.
|
|
*
|
|
* Copyright IBM Corp. 2016
|
|
*/
|
|
#define KMSG_COMPONENT "sclp_cmd"
|
|
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
|
|
|
|
#include <linux/completion.h>
|
|
#include <linux/export.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/init.h>
|
|
#include <linux/err.h>
|
|
|
|
#include <asm/sclp.h>
|
|
|
|
#include "sclp.h"
|
|
|
|
#define SCLP_CMDW_CONFIGURE_PCI 0x001a0001
|
|
#define SCLP_CMDW_DECONFIGURE_PCI 0x001b0001
|
|
|
|
#define SCLP_ATYPE_PCI 2
|
|
|
|
#define SCLP_ERRNOTIFY_AQ_RESET 0
|
|
#define SCLP_ERRNOTIFY_AQ_REPAIR 1
|
|
#define SCLP_ERRNOTIFY_AQ_INFO_LOG 2
|
|
|
|
static DEFINE_MUTEX(sclp_pci_mutex);
|
|
static struct sclp_register sclp_pci_event = {
|
|
.send_mask = EVTYP_ERRNOTIFY_MASK,
|
|
};
|
|
|
|
struct err_notify_evbuf {
|
|
struct evbuf_header header;
|
|
u8 action;
|
|
u8 atype;
|
|
u32 fh;
|
|
u32 fid;
|
|
u8 data[];
|
|
} __packed;
|
|
|
|
struct err_notify_sccb {
|
|
struct sccb_header header;
|
|
struct err_notify_evbuf evbuf;
|
|
} __packed;
|
|
|
|
struct pci_cfg_sccb {
|
|
struct sccb_header header;
|
|
u8 atype; /* adapter type */
|
|
u8 reserved1;
|
|
u16 reserved2;
|
|
u32 aid; /* adapter identifier */
|
|
} __packed;
|
|
|
|
static int do_pci_configure(sclp_cmdw_t cmd, u32 fid)
|
|
{
|
|
struct pci_cfg_sccb *sccb;
|
|
int rc;
|
|
|
|
if (!SCLP_HAS_PCI_RECONFIG)
|
|
return -EOPNOTSUPP;
|
|
|
|
sccb = (struct pci_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
|
|
if (!sccb)
|
|
return -ENOMEM;
|
|
|
|
sccb->header.length = PAGE_SIZE;
|
|
sccb->atype = SCLP_ATYPE_PCI;
|
|
sccb->aid = fid;
|
|
rc = sclp_sync_request(cmd, sccb);
|
|
if (rc)
|
|
goto out;
|
|
switch (sccb->header.response_code) {
|
|
case 0x0020:
|
|
case 0x0120:
|
|
break;
|
|
default:
|
|
pr_warn("configure PCI I/O adapter failed: cmd=0x%08x response=0x%04x\n",
|
|
cmd, sccb->header.response_code);
|
|
rc = -EIO;
|
|
break;
|
|
}
|
|
out:
|
|
free_page((unsigned long) sccb);
|
|
return rc;
|
|
}
|
|
|
|
int sclp_pci_configure(u32 fid)
|
|
{
|
|
return do_pci_configure(SCLP_CMDW_CONFIGURE_PCI, fid);
|
|
}
|
|
EXPORT_SYMBOL(sclp_pci_configure);
|
|
|
|
int sclp_pci_deconfigure(u32 fid)
|
|
{
|
|
return do_pci_configure(SCLP_CMDW_DECONFIGURE_PCI, fid);
|
|
}
|
|
EXPORT_SYMBOL(sclp_pci_deconfigure);
|
|
|
|
static void sclp_pci_callback(struct sclp_req *req, void *data)
|
|
{
|
|
struct completion *completion = data;
|
|
|
|
complete(completion);
|
|
}
|
|
|
|
static int sclp_pci_check_report(struct zpci_report_error_header *report)
|
|
{
|
|
if (report->version != 1)
|
|
return -EINVAL;
|
|
|
|
switch (report->action) {
|
|
case SCLP_ERRNOTIFY_AQ_RESET:
|
|
case SCLP_ERRNOTIFY_AQ_REPAIR:
|
|
case SCLP_ERRNOTIFY_AQ_INFO_LOG:
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (report->length > (PAGE_SIZE - sizeof(struct err_notify_sccb)))
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int sclp_pci_report(struct zpci_report_error_header *report, u32 fh, u32 fid)
|
|
{
|
|
DECLARE_COMPLETION_ONSTACK(completion);
|
|
struct err_notify_sccb *sccb;
|
|
struct sclp_req req;
|
|
int ret;
|
|
|
|
ret = sclp_pci_check_report(report);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mutex_lock(&sclp_pci_mutex);
|
|
ret = sclp_register(&sclp_pci_event);
|
|
if (ret)
|
|
goto out_unlock;
|
|
|
|
if (!(sclp_pci_event.sclp_receive_mask & EVTYP_ERRNOTIFY_MASK)) {
|
|
ret = -EOPNOTSUPP;
|
|
goto out_unregister;
|
|
}
|
|
|
|
sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
|
|
if (!sccb) {
|
|
ret = -ENOMEM;
|
|
goto out_unregister;
|
|
}
|
|
|
|
memset(&req, 0, sizeof(req));
|
|
req.callback_data = &completion;
|
|
req.callback = sclp_pci_callback;
|
|
req.command = SCLP_CMDW_WRITE_EVENT_DATA;
|
|
req.status = SCLP_REQ_FILLED;
|
|
req.sccb = sccb;
|
|
|
|
sccb->evbuf.header.length = sizeof(sccb->evbuf) + report->length;
|
|
sccb->evbuf.header.type = EVTYP_ERRNOTIFY;
|
|
sccb->header.length = sizeof(sccb->header) + sccb->evbuf.header.length;
|
|
|
|
sccb->evbuf.action = report->action;
|
|
sccb->evbuf.atype = SCLP_ATYPE_PCI;
|
|
sccb->evbuf.fh = fh;
|
|
sccb->evbuf.fid = fid;
|
|
|
|
memcpy(sccb->evbuf.data, report->data, report->length);
|
|
|
|
ret = sclp_add_request(&req);
|
|
if (ret)
|
|
goto out_free_req;
|
|
|
|
wait_for_completion(&completion);
|
|
if (req.status != SCLP_REQ_DONE) {
|
|
pr_warn("request failed (status=0x%02x)\n",
|
|
req.status);
|
|
ret = -EIO;
|
|
goto out_free_req;
|
|
}
|
|
|
|
if (sccb->header.response_code != 0x0020) {
|
|
pr_warn("request failed with response code 0x%x\n",
|
|
sccb->header.response_code);
|
|
ret = -EIO;
|
|
}
|
|
|
|
out_free_req:
|
|
free_page((unsigned long) sccb);
|
|
out_unregister:
|
|
sclp_unregister(&sclp_pci_event);
|
|
out_unlock:
|
|
mutex_unlock(&sclp_pci_mutex);
|
|
return ret;
|
|
}
|