linux_dsm_epyc7002/arch/s390/oprofile/init.c
Robert Richter 81ff3478d9 oprofile, s390: Fix uninitialized memory access when writing to oprofilefs
If oprofilefs_ulong_from_user() is called with count equals zero, *val
remains unchanged. Depending on the implementation it might be
uninitialized. Fixing users of oprofilefs_ulong_ from_user().

We missed these s390 changes with:

 913050b oprofile: Fix uninitialized memory access when writing to writing to oprofilefs

Cc: stable@vger.kernel.org  # 3.3+
Signed-off-by: Robert Richter <robert.richter@amd.com>
2012-08-27 14:49:23 +02:00

508 lines
12 KiB
C

/*
* S390 Version
* Copyright IBM Corp. 2002, 2011
* Author(s): Thomas Spatzier (tspat@de.ibm.com)
* Author(s): Mahesh Salgaonkar (mahesh@linux.vnet.ibm.com)
* Author(s): Heinz Graalfs (graalfs@linux.vnet.ibm.com)
* Author(s): Andreas Krebbel (krebbel@linux.vnet.ibm.com)
*
* @remark Copyright 2002-2011 OProfile authors
*/
#include <linux/oprofile.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <asm/processor.h>
#include "../../../drivers/oprofile/oprof.h"
extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth);
#ifdef CONFIG_64BIT
#include "hwsampler.h"
#include "op_counter.h"
#define DEFAULT_INTERVAL 4127518
#define DEFAULT_SDBT_BLOCKS 1
#define DEFAULT_SDB_BLOCKS 511
static unsigned long oprofile_hw_interval = DEFAULT_INTERVAL;
static unsigned long oprofile_min_interval;
static unsigned long oprofile_max_interval;
static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;
static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;
static int hwsampler_enabled;
static int hwsampler_running; /* start_mutex must be held to change */
static int hwsampler_available;
static struct oprofile_operations timer_ops;
struct op_counter_config counter_config;
enum __force_cpu_type {
reserved = 0, /* do not force */
timer,
};
static int force_cpu_type;
static int set_cpu_type(const char *str, struct kernel_param *kp)
{
if (!strcmp(str, "timer")) {
force_cpu_type = timer;
printk(KERN_INFO "oprofile: forcing timer to be returned "
"as cpu type\n");
} else {
force_cpu_type = 0;
}
return 0;
}
module_param_call(cpu_type, set_cpu_type, NULL, NULL, 0);
MODULE_PARM_DESC(cpu_type, "Force legacy basic mode sampling"
"(report cpu_type \"timer\"");
static int oprofile_hwsampler_start(void)
{
int retval;
hwsampler_running = hwsampler_enabled;
if (!hwsampler_running)
return timer_ops.start();
retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks);
if (retval)
return retval;
retval = hwsampler_start_all(oprofile_hw_interval);
if (retval)
hwsampler_deallocate();
return retval;
}
static void oprofile_hwsampler_stop(void)
{
if (!hwsampler_running) {
timer_ops.stop();
return;
}
hwsampler_stop_all();
hwsampler_deallocate();
return;
}
/*
* File ops used for:
* /dev/oprofile/0/enabled
* /dev/oprofile/hwsampling/hwsampler (cpu_type = timer)
*/
static ssize_t hwsampler_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(hwsampler_enabled, buf, count, offset);
}
static ssize_t hwsampler_write(struct file *file, char const __user *buf,
size_t count, loff_t *offset)
{
unsigned long val;
int retval;
if (*offset)
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval <= 0)
return retval;
if (val != 0 && val != 1)
return -EINVAL;
if (oprofile_started)
/*
* save to do without locking as we set
* hwsampler_running in start() when start_mutex is
* held
*/
return -EBUSY;
hwsampler_enabled = val;
return count;
}
static const struct file_operations hwsampler_fops = {
.read = hwsampler_read,
.write = hwsampler_write,
};
/*
* File ops used for:
* /dev/oprofile/0/count
* /dev/oprofile/hwsampling/hw_interval (cpu_type = timer)
*
* Make sure that the value is within the hardware range.
*/
static ssize_t hw_interval_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(oprofile_hw_interval, buf,
count, offset);
}
static ssize_t hw_interval_write(struct file *file, char const __user *buf,
size_t count, loff_t *offset)
{
unsigned long val;
int retval;
if (*offset)
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval <= 0)
return retval;
if (val < oprofile_min_interval)
oprofile_hw_interval = oprofile_min_interval;
else if (val > oprofile_max_interval)
oprofile_hw_interval = oprofile_max_interval;
else
oprofile_hw_interval = val;
return count;
}
static const struct file_operations hw_interval_fops = {
.read = hw_interval_read,
.write = hw_interval_write,
};
/*
* File ops used for:
* /dev/oprofile/0/event
* Only a single event with number 0 is supported with this counter.
*
* /dev/oprofile/0/unit_mask
* This is a dummy file needed by the user space tools.
* No value other than 0 is accepted or returned.
*/
static ssize_t hwsampler_zero_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(0, buf, count, offset);
}
static ssize_t hwsampler_zero_write(struct file *file, char const __user *buf,
size_t count, loff_t *offset)
{
unsigned long val;
int retval;
if (*offset)
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval <= 0)
return retval;
if (val != 0)
return -EINVAL;
return count;
}
static const struct file_operations zero_fops = {
.read = hwsampler_zero_read,
.write = hwsampler_zero_write,
};
/* /dev/oprofile/0/kernel file ops. */
static ssize_t hwsampler_kernel_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(counter_config.kernel,
buf, count, offset);
}
static ssize_t hwsampler_kernel_write(struct file *file, char const __user *buf,
size_t count, loff_t *offset)
{
unsigned long val;
int retval;
if (*offset)
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval <= 0)
return retval;
if (val != 0 && val != 1)
return -EINVAL;
counter_config.kernel = val;
return count;
}
static const struct file_operations kernel_fops = {
.read = hwsampler_kernel_read,
.write = hwsampler_kernel_write,
};
/* /dev/oprofile/0/user file ops. */
static ssize_t hwsampler_user_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(counter_config.user,
buf, count, offset);
}
static ssize_t hwsampler_user_write(struct file *file, char const __user *buf,
size_t count, loff_t *offset)
{
unsigned long val;
int retval;
if (*offset)
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval <= 0)
return retval;
if (val != 0 && val != 1)
return -EINVAL;
counter_config.user = val;
return count;
}
static const struct file_operations user_fops = {
.read = hwsampler_user_read,
.write = hwsampler_user_write,
};
/*
* File ops used for: /dev/oprofile/timer/enabled
* The value always has to be the inverted value of hwsampler_enabled. So
* no separate variable is created. That way we do not need locking.
*/
static ssize_t timer_enabled_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
return oprofilefs_ulong_to_user(!hwsampler_enabled, buf, count, offset);
}
static ssize_t timer_enabled_write(struct file *file, char const __user *buf,
size_t count, loff_t *offset)
{
unsigned long val;
int retval;
if (*offset)
return -EINVAL;
retval = oprofilefs_ulong_from_user(&val, buf, count);
if (retval <= 0)
return retval;
if (val != 0 && val != 1)
return -EINVAL;
/* Timer cannot be disabled without having hardware sampling. */
if (val == 0 && !hwsampler_available)
return -EINVAL;
if (oprofile_started)
/*
* save to do without locking as we set
* hwsampler_running in start() when start_mutex is
* held
*/
return -EBUSY;
hwsampler_enabled = !val;
return count;
}
static const struct file_operations timer_enabled_fops = {
.read = timer_enabled_read,
.write = timer_enabled_write,
};
static int oprofile_create_hwsampling_files(struct super_block *sb,
struct dentry *root)
{
struct dentry *dir;
dir = oprofilefs_mkdir(sb, root, "timer");
if (!dir)
return -EINVAL;
oprofilefs_create_file(sb, dir, "enabled", &timer_enabled_fops);
if (!hwsampler_available)
return 0;
/* reinitialize default values */
hwsampler_enabled = 1;
counter_config.kernel = 1;
counter_config.user = 1;
if (!force_cpu_type) {
/*
* Create the counter file system. A single virtual
* counter is created which can be used to
* enable/disable hardware sampling dynamically from
* user space. The user space will configure a single
* counter with a single event. The value of 'event'
* and 'unit_mask' are not evaluated by the kernel code
* and can only be set to 0.
*/
dir = oprofilefs_mkdir(sb, root, "0");
if (!dir)
return -EINVAL;
oprofilefs_create_file(sb, dir, "enabled", &hwsampler_fops);
oprofilefs_create_file(sb, dir, "event", &zero_fops);
oprofilefs_create_file(sb, dir, "count", &hw_interval_fops);
oprofilefs_create_file(sb, dir, "unit_mask", &zero_fops);
oprofilefs_create_file(sb, dir, "kernel", &kernel_fops);
oprofilefs_create_file(sb, dir, "user", &user_fops);
oprofilefs_create_ulong(sb, dir, "hw_sdbt_blocks",
&oprofile_sdbt_blocks);
} else {
/*
* Hardware sampling can be used but the cpu_type is
* forced to timer in order to deal with legacy user
* space tools. The /dev/oprofile/hwsampling fs is
* provided in that case.
*/
dir = oprofilefs_mkdir(sb, root, "hwsampling");
if (!dir)
return -EINVAL;
oprofilefs_create_file(sb, dir, "hwsampler",
&hwsampler_fops);
oprofilefs_create_file(sb, dir, "hw_interval",
&hw_interval_fops);
oprofilefs_create_ro_ulong(sb, dir, "hw_min_interval",
&oprofile_min_interval);
oprofilefs_create_ro_ulong(sb, dir, "hw_max_interval",
&oprofile_max_interval);
oprofilefs_create_ulong(sb, dir, "hw_sdbt_blocks",
&oprofile_sdbt_blocks);
}
return 0;
}
static int oprofile_hwsampler_init(struct oprofile_operations *ops)
{
/*
* Initialize the timer mode infrastructure as well in order
* to be able to switch back dynamically. oprofile_timer_init
* is not supposed to fail.
*/
if (oprofile_timer_init(ops))
BUG();
memcpy(&timer_ops, ops, sizeof(timer_ops));
ops->create_files = oprofile_create_hwsampling_files;
/*
* If the user space tools do not support newer cpu types,
* the force_cpu_type module parameter
* can be used to always return \"timer\" as cpu type.
*/
if (force_cpu_type != timer) {
struct cpuid id;
get_cpu_id (&id);
switch (id.machine) {
case 0x2097: case 0x2098: ops->cpu_type = "s390/z10"; break;
case 0x2817: case 0x2818: ops->cpu_type = "s390/z196"; break;
default: return -ENODEV;
}
}
if (hwsampler_setup())
return -ENODEV;
/*
* Query the range for the sampling interval from the
* hardware.
*/
oprofile_min_interval = hwsampler_query_min_interval();
if (oprofile_min_interval == 0)
return -ENODEV;
oprofile_max_interval = hwsampler_query_max_interval();
if (oprofile_max_interval == 0)
return -ENODEV;
/* The initial value should be sane */
if (oprofile_hw_interval < oprofile_min_interval)
oprofile_hw_interval = oprofile_min_interval;
if (oprofile_hw_interval > oprofile_max_interval)
oprofile_hw_interval = oprofile_max_interval;
printk(KERN_INFO "oprofile: System z hardware sampling "
"facility found.\n");
ops->start = oprofile_hwsampler_start;
ops->stop = oprofile_hwsampler_stop;
return 0;
}
static void oprofile_hwsampler_exit(void)
{
hwsampler_shutdown();
}
#endif /* CONFIG_64BIT */
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
ops->backtrace = s390_backtrace;
#ifdef CONFIG_64BIT
/*
* -ENODEV is not reported to the caller. The module itself
* will use the timer mode sampling as fallback and this is
* always available.
*/
hwsampler_available = oprofile_hwsampler_init(ops) == 0;
return 0;
#else
return -ENODEV;
#endif
}
void oprofile_arch_exit(void)
{
#ifdef CONFIG_64BIT
oprofile_hwsampler_exit();
#endif
}