tmp_suning_uos_patched/arch/s390/hypfs/hypfs_vm.c
Michael Holzheu 2fcb3686e1 [S390] hypfs: Move buffer allocation from open to read
Currently the buffer for diagnose data is allocated in the open function
of the debugfs file and is released in the close function. This has the
drawback that a user (root) can pin that memory by not closing the file.
This patch moves the buffer allocation to the read function. The buffer is
automatically released after the buffer is copied to userspace.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-01-05 12:47:27 +01:00

284 lines
6.7 KiB
C

/*
* Hypervisor filesystem for Linux on s390. z/VM implementation.
*
* Copyright (C) IBM Corp. 2006
* Author(s): Michael Holzheu <holzheu@de.ibm.com>
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <asm/ebcdic.h>
#include <asm/timex.h>
#include "hypfs.h"
#define NAME_LEN 8
#define DBFS_D2FC_HDR_VERSION 0
static char local_guest[] = " ";
static char all_guests[] = "* ";
static char *guest_query;
struct diag2fc_data {
__u32 version;
__u32 flags;
__u64 used_cpu;
__u64 el_time;
__u64 mem_min_kb;
__u64 mem_max_kb;
__u64 mem_share_kb;
__u64 mem_used_kb;
__u32 pcpus;
__u32 lcpus;
__u32 vcpus;
__u32 cpu_min;
__u32 cpu_max;
__u32 cpu_shares;
__u32 cpu_use_samp;
__u32 cpu_delay_samp;
__u32 page_wait_samp;
__u32 idle_samp;
__u32 other_samp;
__u32 total_samp;
char guest_name[NAME_LEN];
};
struct diag2fc_parm_list {
char userid[NAME_LEN];
char aci_grp[NAME_LEN];
__u64 addr;
__u32 size;
__u32 fmt;
};
static int diag2fc(int size, char* query, void *addr)
{
unsigned long residual_cnt;
unsigned long rc;
struct diag2fc_parm_list parm_list;
memcpy(parm_list.userid, query, NAME_LEN);
ASCEBC(parm_list.userid, NAME_LEN);
parm_list.addr = (unsigned long) addr ;
parm_list.size = size;
parm_list.fmt = 0x02;
memset(parm_list.aci_grp, 0x40, NAME_LEN);
rc = -1;
asm volatile(
" diag %0,%1,0x2fc\n"
"0:\n"
EX_TABLE(0b,0b)
: "=d" (residual_cnt), "+d" (rc) : "0" (&parm_list) : "memory");
if ((rc != 0 ) && (rc != -2))
return rc;
else
return -residual_cnt;
}
/*
* Allocate buffer for "query" and store diag 2fc at "offset"
*/
static void *diag2fc_store(char *query, unsigned int *count, int offset)
{
void *data;
int size;
do {
size = diag2fc(0, query, NULL);
if (size < 0)
return ERR_PTR(-EACCES);
data = vmalloc(size + offset);
if (!data)
return ERR_PTR(-ENOMEM);
if (diag2fc(size, query, data + offset) == 0)
break;
vfree(data);
} while (1);
*count = (size / sizeof(struct diag2fc_data));
return data;
}
static void diag2fc_free(const void *data)
{
vfree(data);
}
#define ATTRIBUTE(sb, dir, name, member) \
do { \
void *rc; \
rc = hypfs_create_u64(sb, dir, name, member); \
if (IS_ERR(rc)) \
return PTR_ERR(rc); \
} while(0)
static int hpyfs_vm_create_guest(struct super_block *sb,
struct dentry *systems_dir,
struct diag2fc_data *data)
{
char guest_name[NAME_LEN + 1] = {};
struct dentry *guest_dir, *cpus_dir, *samples_dir, *mem_dir;
int dedicated_flag, capped_value;
capped_value = (data->flags & 0x00000006) >> 1;
dedicated_flag = (data->flags & 0x00000008) >> 3;
/* guest dir */
memcpy(guest_name, data->guest_name, NAME_LEN);
EBCASC(guest_name, NAME_LEN);
strim(guest_name);
guest_dir = hypfs_mkdir(sb, systems_dir, guest_name);
if (IS_ERR(guest_dir))
return PTR_ERR(guest_dir);
ATTRIBUTE(sb, guest_dir, "onlinetime_us", data->el_time);
/* logical cpu information */
cpus_dir = hypfs_mkdir(sb, guest_dir, "cpus");
if (IS_ERR(cpus_dir))
return PTR_ERR(cpus_dir);
ATTRIBUTE(sb, cpus_dir, "cputime_us", data->used_cpu);
ATTRIBUTE(sb, cpus_dir, "capped", capped_value);
ATTRIBUTE(sb, cpus_dir, "dedicated", dedicated_flag);
ATTRIBUTE(sb, cpus_dir, "count", data->vcpus);
ATTRIBUTE(sb, cpus_dir, "weight_min", data->cpu_min);
ATTRIBUTE(sb, cpus_dir, "weight_max", data->cpu_max);
ATTRIBUTE(sb, cpus_dir, "weight_cur", data->cpu_shares);
/* memory information */
mem_dir = hypfs_mkdir(sb, guest_dir, "mem");
if (IS_ERR(mem_dir))
return PTR_ERR(mem_dir);
ATTRIBUTE(sb, mem_dir, "min_KiB", data->mem_min_kb);
ATTRIBUTE(sb, mem_dir, "max_KiB", data->mem_max_kb);
ATTRIBUTE(sb, mem_dir, "used_KiB", data->mem_used_kb);
ATTRIBUTE(sb, mem_dir, "share_KiB", data->mem_share_kb);
/* samples */
samples_dir = hypfs_mkdir(sb, guest_dir, "samples");
if (IS_ERR(samples_dir))
return PTR_ERR(samples_dir);
ATTRIBUTE(sb, samples_dir, "cpu_using", data->cpu_use_samp);
ATTRIBUTE(sb, samples_dir, "cpu_delay", data->cpu_delay_samp);
ATTRIBUTE(sb, samples_dir, "mem_delay", data->page_wait_samp);
ATTRIBUTE(sb, samples_dir, "idle", data->idle_samp);
ATTRIBUTE(sb, samples_dir, "other", data->other_samp);
ATTRIBUTE(sb, samples_dir, "total", data->total_samp);
return 0;
}
int hypfs_vm_create_files(struct super_block *sb, struct dentry *root)
{
struct dentry *dir, *file;
struct diag2fc_data *data;
unsigned int count = 0;
int rc, i;
data = diag2fc_store(guest_query, &count, 0);
if (IS_ERR(data))
return PTR_ERR(data);
/* Hpervisor Info */
dir = hypfs_mkdir(sb, root, "hyp");
if (IS_ERR(dir)) {
rc = PTR_ERR(dir);
goto failed;
}
file = hypfs_create_str(sb, dir, "type", "z/VM Hypervisor");
if (IS_ERR(file)) {
rc = PTR_ERR(file);
goto failed;
}
/* physical cpus */
dir = hypfs_mkdir(sb, root, "cpus");
if (IS_ERR(dir)) {
rc = PTR_ERR(dir);
goto failed;
}
file = hypfs_create_u64(sb, dir, "count", data->lcpus);
if (IS_ERR(file)) {
rc = PTR_ERR(file);
goto failed;
}
/* guests */
dir = hypfs_mkdir(sb, root, "systems");
if (IS_ERR(dir)) {
rc = PTR_ERR(dir);
goto failed;
}
for (i = 0; i < count; i++) {
rc = hpyfs_vm_create_guest(sb, dir, &(data[i]));
if (rc)
goto failed;
}
diag2fc_free(data);
return 0;
failed:
diag2fc_free(data);
return rc;
}
struct dbfs_d2fc_hdr {
u64 len; /* Length of d2fc buffer without header */
u16 version; /* Version of header */
char tod_ext[16]; /* TOD clock for d2fc */
u64 count; /* Number of VM guests in d2fc buffer */
char reserved[30];
} __attribute__ ((packed));
struct dbfs_d2fc {
struct dbfs_d2fc_hdr hdr; /* 64 byte header */
char buf[]; /* d2fc buffer */
} __attribute__ ((packed));
static int dbfs_diag2fc_create(void **data, void **data_free_ptr, size_t *size)
{
struct dbfs_d2fc *d2fc;
unsigned int count;
d2fc = diag2fc_store(guest_query, &count, sizeof(d2fc->hdr));
if (IS_ERR(d2fc))
return PTR_ERR(d2fc);
get_clock_ext(d2fc->hdr.tod_ext);
d2fc->hdr.len = count * sizeof(struct diag2fc_data);
d2fc->hdr.version = DBFS_D2FC_HDR_VERSION;
d2fc->hdr.count = count;
memset(&d2fc->hdr.reserved, 0, sizeof(d2fc->hdr.reserved));
*data = d2fc;
*data_free_ptr = d2fc;
*size = d2fc->hdr.len + sizeof(struct dbfs_d2fc_hdr);
return 0;
}
static struct hypfs_dbfs_file dbfs_file_2fc = {
.name = "diag_2fc",
.data_create = dbfs_diag2fc_create,
.data_free = diag2fc_free,
};
int hypfs_vm_init(void)
{
if (!MACHINE_IS_VM)
return 0;
if (diag2fc(0, all_guests, NULL) > 0)
guest_query = all_guests;
else if (diag2fc(0, local_guest, NULL) > 0)
guest_query = local_guest;
else
return -EACCES;
return hypfs_dbfs_create_file(&dbfs_file_2fc);
}
void hypfs_vm_exit(void)
{
if (!MACHINE_IS_VM)
return;
hypfs_dbfs_remove_file(&dbfs_file_2fc);
}