linux_dsm_epyc7002/arch/ia64/sn/kernel/sn2/prominfo_proc.c
Alexey Dobriyan 99b7623380 proc 2/2: remove struct proc_dir_entry::owner
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-03-31 01:14:44 +04:00

275 lines
6.9 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1999,2001-2004, 2006 Silicon Graphics, Inc. All Rights Reserved.
*
* Module to export the system's Firmware Interface Tables, including
* PROM revision numbers and banners, in /proc
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/nodemask.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/sn/sn_sal.h>
#include <asm/sn/sn_cpuid.h>
#include <asm/sn/addrs.h>
MODULE_DESCRIPTION("PROM version reporting for /proc");
MODULE_AUTHOR("Chad Talbott");
MODULE_LICENSE("GPL");
/* Standard Intel FIT entry types */
#define FIT_ENTRY_FIT_HEADER 0x00 /* FIT header entry */
#define FIT_ENTRY_PAL_B 0x01 /* PAL_B entry */
/* Entries 0x02 through 0x0D reserved by Intel */
#define FIT_ENTRY_PAL_A_PROC 0x0E /* Processor-specific PAL_A entry */
#define FIT_ENTRY_PAL_A 0x0F /* PAL_A entry, same as... */
#define FIT_ENTRY_PAL_A_GEN 0x0F /* ...Generic PAL_A entry */
#define FIT_ENTRY_UNUSED 0x7F /* Unused (reserved by Intel?) */
/* OEM-defined entries range from 0x10 to 0x7E. */
#define FIT_ENTRY_SAL_A 0x10 /* SAL_A entry */
#define FIT_ENTRY_SAL_B 0x11 /* SAL_B entry */
#define FIT_ENTRY_SALRUNTIME 0x12 /* SAL runtime entry */
#define FIT_ENTRY_EFI 0x1F /* EFI entry */
#define FIT_ENTRY_FPSWA 0x20 /* embedded fpswa entry */
#define FIT_ENTRY_VMLINUX 0x21 /* embedded vmlinux entry */
#define FIT_MAJOR_SHIFT (32 + 8)
#define FIT_MAJOR_MASK ((1 << 8) - 1)
#define FIT_MINOR_SHIFT 32
#define FIT_MINOR_MASK ((1 << 8) - 1)
#define FIT_MAJOR(q) \
((unsigned) ((q) >> FIT_MAJOR_SHIFT) & FIT_MAJOR_MASK)
#define FIT_MINOR(q) \
((unsigned) ((q) >> FIT_MINOR_SHIFT) & FIT_MINOR_MASK)
#define FIT_TYPE_SHIFT (32 + 16)
#define FIT_TYPE_MASK ((1 << 7) - 1)
#define FIT_TYPE(q) \
((unsigned) ((q) >> FIT_TYPE_SHIFT) & FIT_TYPE_MASK)
struct fit_type_map_t {
unsigned char type;
const char *name;
};
static const struct fit_type_map_t fit_entry_types[] = {
{FIT_ENTRY_FIT_HEADER, "FIT Header"},
{FIT_ENTRY_PAL_A_GEN, "Generic PAL_A"},
{FIT_ENTRY_PAL_A_PROC, "Processor-specific PAL_A"},
{FIT_ENTRY_PAL_A, "PAL_A"},
{FIT_ENTRY_PAL_B, "PAL_B"},
{FIT_ENTRY_SAL_A, "SAL_A"},
{FIT_ENTRY_SAL_B, "SAL_B"},
{FIT_ENTRY_SALRUNTIME, "SAL runtime"},
{FIT_ENTRY_EFI, "EFI"},
{FIT_ENTRY_VMLINUX, "Embedded Linux"},
{FIT_ENTRY_FPSWA, "Embedded FPSWA"},
{FIT_ENTRY_UNUSED, "Unused"},
{0xff, "Error"},
};
static const char *fit_type_name(unsigned char type)
{
struct fit_type_map_t const *mapp;
for (mapp = fit_entry_types; mapp->type != 0xff; mapp++)
if (type == mapp->type)
return mapp->name;
if ((type > FIT_ENTRY_PAL_A) && (type < FIT_ENTRY_UNUSED))
return "OEM type";
if ((type > FIT_ENTRY_PAL_B) && (type < FIT_ENTRY_PAL_A))
return "Reserved";
return "Unknown type";
}
static int
get_fit_entry(unsigned long nasid, int index, unsigned long *fentry,
char *banner, int banlen)
{
return ia64_sn_get_fit_compt(nasid, index, fentry, banner, banlen);
}
/*
* These two routines display the FIT table for each node.
*/
static int dump_fit_entry(char *page, unsigned long *fentry)
{
unsigned type;
type = FIT_TYPE(fentry[1]);
return sprintf(page, "%02x %-25s %x.%02x %016lx %u\n",
type,
fit_type_name(type),
FIT_MAJOR(fentry[1]), FIT_MINOR(fentry[1]),
fentry[0],
/* mult by sixteen to get size in bytes */
(unsigned)(fentry[1] & 0xffffff) * 16);
}
/*
* We assume that the fit table will be small enough that we can print
* the whole thing into one page. (This is true for our default 16kB
* pages -- each entry is about 60 chars wide when printed.) I read
* somewhere that the maximum size of the FIT is 128 entries, so we're
* OK except for 4kB pages (and no one is going to do that on SN
* anyway).
*/
static int
dump_fit(char *page, unsigned long nasid)
{
unsigned long fentry[2];
int index;
char *p;
p = page;
for (index=0;;index++) {
BUG_ON(index * 60 > PAGE_SIZE);
if (get_fit_entry(nasid, index, fentry, NULL, 0))
break;
p += dump_fit_entry(p, fentry);
}
return p - page;
}
static int
dump_version(char *page, unsigned long nasid)
{
unsigned long fentry[2];
char banner[128];
int index;
int len;
for (index = 0; ; index++) {
if (get_fit_entry(nasid, index, fentry, banner,
sizeof(banner)))
return 0;
if (FIT_TYPE(fentry[1]) == FIT_ENTRY_SAL_A)
break;
}
len = sprintf(page, "%x.%02x\n", FIT_MAJOR(fentry[1]),
FIT_MINOR(fentry[1]));
page += len;
if (banner[0])
len += snprintf(page, PAGE_SIZE-len, "%s\n", banner);
return len;
}
/* same as in proc_misc.c */
static int
proc_calc_metrics(char *page, char **start, off_t off, int count, int *eof,
int len)
{
if (len <= off + count)
*eof = 1;
*start = page + off;
len -= off;
if (len > count)
len = count;
if (len < 0)
len = 0;
return len;
}
static int
read_version_entry(char *page, char **start, off_t off, int count, int *eof,
void *data)
{
int len;
/* data holds the NASID of the node */
len = dump_version(page, (unsigned long)data);
len = proc_calc_metrics(page, start, off, count, eof, len);
return len;
}
static int
read_fit_entry(char *page, char **start, off_t off, int count, int *eof,
void *data)
{
int len;
/* data holds the NASID of the node */
len = dump_fit(page, (unsigned long)data);
len = proc_calc_metrics(page, start, off, count, eof, len);
return len;
}
/* module entry points */
int __init prominfo_init(void);
void __exit prominfo_exit(void);
module_init(prominfo_init);
module_exit(prominfo_exit);
static struct proc_dir_entry **proc_entries;
static struct proc_dir_entry *sgi_prominfo_entry;
#define NODE_NAME_LEN 11
int __init prominfo_init(void)
{
struct proc_dir_entry **entp;
cnodeid_t cnodeid;
unsigned long nasid;
int size;
char name[NODE_NAME_LEN];
if (!ia64_platform_is("sn2"))
return 0;
size = num_online_nodes() * sizeof(struct proc_dir_entry *);
proc_entries = kzalloc(size, GFP_KERNEL);
if (!proc_entries)
return -ENOMEM;
sgi_prominfo_entry = proc_mkdir("sgi_prominfo", NULL);
entp = proc_entries;
for_each_online_node(cnodeid) {
sprintf(name, "node%d", cnodeid);
*entp = proc_mkdir(name, sgi_prominfo_entry);
nasid = cnodeid_to_nasid(cnodeid);
create_proc_read_entry("fit", 0, *entp, read_fit_entry,
(void *)nasid);
create_proc_read_entry("version", 0, *entp,
read_version_entry, (void *)nasid);
entp++;
}
return 0;
}
void __exit prominfo_exit(void)
{
struct proc_dir_entry **entp;
unsigned int cnodeid;
char name[NODE_NAME_LEN];
entp = proc_entries;
for_each_online_node(cnodeid) {
remove_proc_entry("fit", *entp);
remove_proc_entry("version", *entp);
sprintf(name, "node%d", cnodeid);
remove_proc_entry(name, sgi_prominfo_entry);
entp++;
}
remove_proc_entry("sgi_prominfo", NULL);
kfree(proc_entries);
}