[PATCH] parisc: perf: Handle return NULL error from ioremap_nocache.

From: Arvind Yadav
Date: Tue Mar 14 2017 - 05:55:22 EST


Here, If ioremap_nocache will fail. It will return NULL.
Kernel can run into a NULL-pointer dereference.
This error check will avoid NULL pointer dereference.

This patch will remove coding style errors.
- ERROR: code indent should use tabs where possible.
- ERROR: trailing whitespace.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
---
arch/parisc/kernel/perf.c | 90 +++++++++++++++++++++++++----------------------
1 file changed, 47 insertions(+), 43 deletions(-)

diff --git a/arch/parisc/kernel/perf.c b/arch/parisc/kernel/perf.c
index e282a51..4313624 100644
--- a/arch/parisc/kernel/perf.c
+++ b/arch/parisc/kernel/perf.c
@@ -39,7 +39,7 @@
* the PDC INTRIGUE calls. This is done to eliminate bugs introduced
* in various PDC revisions. The code is much more maintainable
* and reliable this way vs having to debug on every version of PDC
- * on every box.
+ * on every box.
*/

#include <linux/capability.h>
@@ -195,7 +195,7 @@ struct rdr_tbl_ent {
static int perf_release(struct inode *inode, struct file *file);
static int perf_open(struct inode *inode, struct file *file);
static ssize_t perf_read(struct file *file, char __user *buf, size_t cnt, loff_t *ppos);
-static ssize_t perf_write(struct file *file, const char __user *buf, size_t count,
+static ssize_t perf_write(struct file *file, const char __user *buf, size_t count,
loff_t *ppos);
static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
static void perf_start_counters(void);
@@ -222,7 +222,7 @@ static ssize_t perf_write(struct file *file, const char __user *buf, size_t coun
/*
* configure:
*
- * Configure the cpu with a given data image. First turn off the counters,
+ * Configure the cpu with a given data image. First turn off the counters,
* then download the image, then turn the counters back on.
*/
static int perf_config(uint32_t *image_ptr)
@@ -234,7 +234,7 @@ static int perf_config(uint32_t *image_ptr)
error = perf_stop_counters(raddr);
if (error != 0) {
printk("perf_config: perf_stop_counters = %ld\n", error);
- return -EINVAL;
+ return -EINVAL;
}

printk("Preparing to write image\n");
@@ -242,7 +242,7 @@ static int perf_config(uint32_t *image_ptr)
error = perf_write_image((uint64_t *)image_ptr);
if (error != 0) {
printk("perf_config: DOWNLOAD = %ld\n", error);
- return -EINVAL;
+ return -EINVAL;
}

printk("Preparing to start counters\n");
@@ -254,7 +254,7 @@ static int perf_config(uint32_t *image_ptr)
}

/*
- * Open the device and initialize all of its memory. The device is only
+ * Open the device and initialize all of its memory. The device is only
* opened once, but can be "queried" by multiple processes that know its
* file descriptor.
*/
@@ -298,7 +298,7 @@ static ssize_t perf_read(struct file *file, char __user *buf, size_t cnt, loff_t
* called on the processor that the download should happen
* on.
*/
-static ssize_t perf_write(struct file *file, const char __user *buf, size_t count,
+static ssize_t perf_write(struct file *file, const char __user *buf, size_t count,
loff_t *ppos)
{
size_t image_size;
@@ -306,11 +306,11 @@ static ssize_t perf_write(struct file *file, const char __user *buf, size_t coun
uint32_t interface_type;
uint32_t test;

- if (perf_processor_interface == ONYX_INTF)
+ if (perf_processor_interface == ONYX_INTF)
image_size = PCXU_IMAGE_SIZE;
- else if (perf_processor_interface == CUDA_INTF)
+ else if (perf_processor_interface == CUDA_INTF)
image_size = PCXW_IMAGE_SIZE;
- else
+ else
return -EFAULT;

if (!capable(CAP_SYS_ADMIN))
@@ -330,22 +330,22 @@ static ssize_t perf_write(struct file *file, const char __user *buf, size_t coun

/* First check the machine type is correct for
the requested image */
- if (((perf_processor_interface == CUDA_INTF) &&
- (interface_type != CUDA_INTF)) ||
- ((perf_processor_interface == ONYX_INTF) &&
- (interface_type != ONYX_INTF)))
+ if (((perf_processor_interface == CUDA_INTF) &&
+ (interface_type != CUDA_INTF)) ||
+ ((perf_processor_interface == ONYX_INTF) &&
+ (interface_type != ONYX_INTF)))
return -EINVAL;

/* Next check to make sure the requested image
is valid */
- if (((interface_type == CUDA_INTF) &&
+ if (((interface_type == CUDA_INTF) &&
(test >= MAX_CUDA_IMAGES)) ||
- ((interface_type == ONYX_INTF) &&
- (test >= MAX_ONYX_IMAGES)))
+ ((interface_type == ONYX_INTF) &&
+ (test >= MAX_ONYX_IMAGES)))
return -EINVAL;

/* Copy the image into the processor */
- if (interface_type == CUDA_INTF)
+ if (interface_type == CUDA_INTF)
return perf_config(cuda_images[test]);
else
return perf_config(onyx_images[test]);
@@ -359,7 +359,7 @@ static ssize_t perf_write(struct file *file, const char __user *buf, size_t coun
static void perf_patch_images(void)
{
#if 0 /* FIXME!! */
-/*
+/*
* NOTE: this routine is VERY specific to the current TLB image.
* If the image is changed, this routine might also need to be changed.
*/
@@ -367,9 +367,9 @@ static void perf_patch_images(void)
extern void $i_dtlb_miss_2_0();
extern void PA2_0_iva();

- /*
+ /*
* We can only use the lower 32-bits, the upper 32-bits should be 0
- * anyway given this is in the kernel
+ * anyway given this is in the kernel
*/
uint32_t itlb_addr = (uint32_t)&($i_itlb_miss_2_0);
uint32_t dtlb_addr = (uint32_t)&($i_dtlb_miss_2_0);
@@ -377,21 +377,21 @@ static void perf_patch_images(void)

if (perf_processor_interface == ONYX_INTF) {
/* clear last 2 bytes */
- onyx_images[TLBMISS][15] &= 0xffffff00;
+ onyx_images[TLBMISS][15] &= 0xffffff00;
/* set 2 bytes */
onyx_images[TLBMISS][15] |= (0x000000ff&((dtlb_addr) >> 24));
onyx_images[TLBMISS][16] = (dtlb_addr << 8)&0xffffff00;
onyx_images[TLBMISS][17] = itlb_addr;

/* clear last 2 bytes */
- onyx_images[TLBHANDMISS][15] &= 0xffffff00;
+ onyx_images[TLBHANDMISS][15] &= 0xffffff00;
/* set 2 bytes */
onyx_images[TLBHANDMISS][15] |= (0x000000ff&((dtlb_addr) >> 24));
onyx_images[TLBHANDMISS][16] = (dtlb_addr << 8)&0xffffff00;
onyx_images[TLBHANDMISS][17] = itlb_addr;

/* clear last 2 bytes */
- onyx_images[BIG_CPI][15] &= 0xffffff00;
+ onyx_images[BIG_CPI][15] &= 0xffffff00;
/* set 2 bytes */
onyx_images[BIG_CPI][15] |= (0x000000ff&((dtlb_addr) >> 24));
onyx_images[BIG_CPI][16] = (dtlb_addr << 8)&0xffffff00;
@@ -404,24 +404,24 @@ static void perf_patch_images(void)

} else if (perf_processor_interface == CUDA_INTF) {
/* Cuda interface */
- cuda_images[TLBMISS][16] =
+ cuda_images[TLBMISS][16] =
(cuda_images[TLBMISS][16]&0xffff0000) |
((dtlb_addr >> 8)&0x0000ffff);
- cuda_images[TLBMISS][17] =
+ cuda_images[TLBMISS][17] =
((dtlb_addr << 24)&0xff000000) | ((itlb_addr >> 16)&0x000000ff);
cuda_images[TLBMISS][18] = (itlb_addr << 16)&0xffff0000;

- cuda_images[TLBHANDMISS][16] =
+ cuda_images[TLBHANDMISS][16] =
(cuda_images[TLBHANDMISS][16]&0xffff0000) |
((dtlb_addr >> 8)&0x0000ffff);
- cuda_images[TLBHANDMISS][17] =
+ cuda_images[TLBHANDMISS][17] =
((dtlb_addr << 24)&0xff000000) | ((itlb_addr >> 16)&0x000000ff);
cuda_images[TLBHANDMISS][18] = (itlb_addr << 16)&0xffff0000;

- cuda_images[BIG_CPI][16] =
+ cuda_images[BIG_CPI][16] =
(cuda_images[BIG_CPI][16]&0xffff0000) |
((dtlb_addr >> 8)&0x0000ffff);
- cuda_images[BIG_CPI][17] =
+ cuda_images[BIG_CPI][17] =
((dtlb_addr << 24)&0xff000000) | ((itlb_addr >> 16)&0x000000ff);
cuda_images[BIG_CPI][18] = (itlb_addr << 16)&0xffff0000;
} else {
@@ -433,7 +433,7 @@ static void perf_patch_images(void)

/*
* ioctl routine
- * All routines effect the processor that they are executed on. Thus you
+ * All routines effect the processor that they are executed on. Thus you
* must be running on the processor that you wish to change.
*/

@@ -459,7 +459,7 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}

/* copy out the Counters */
- if (copy_to_user((void __user *)arg, raddr,
+ if (copy_to_user((void __user *)arg, raddr,
sizeof (raddr)) != 0) {
error = -EFAULT;
break;
@@ -487,7 +487,7 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
.open = perf_open,
.release = perf_release
};
-
+
static struct miscdevice perf_dev = {
MISC_DYNAMIC_MINOR,
PA_PERF_DEV,
@@ -595,7 +595,7 @@ static int perf_stop_counters(uint32_t *raddr)
/* OR sticky2 (bit 1496) to counter2 bit 32 */
tmp64 |= (userbuf[23] >> 8) & 0x0000000080000000;
raddr[2] = (uint32_t)tmp64;
-
+
/* Counter3 is bits 1497 to 1528 */
tmp64 = (userbuf[23] >> 7) & 0x00000000ffffffff;
/* OR sticky3 (bit 1529) to counter3 bit 32 */
@@ -617,7 +617,7 @@ static int perf_stop_counters(uint32_t *raddr)
userbuf[22] = 0;
userbuf[23] = 0;

- /*
+ /*
* Write back the zeroed bytes + the image given
* the read was destructive.
*/
@@ -625,13 +625,13 @@ static int perf_stop_counters(uint32_t *raddr)
} else {

/*
- * Read RDR-15 which contains the counters and sticky bits
+ * Read RDR-15 which contains the counters and sticky bits
*/
if (!perf_rdr_read_ubuf(15, userbuf)) {
return -13;
}

- /*
+ /*
* Clear out the counters
*/
perf_rdr_clear(15);
@@ -644,7 +644,7 @@ static int perf_stop_counters(uint32_t *raddr)
raddr[2] = (uint32_t)((userbuf[1] >> 32) & 0x00000000ffffffffUL);
raddr[3] = (uint32_t)(userbuf[1] & 0x00000000ffffffffUL);
}
-
+
return 0;
}

@@ -682,7 +682,7 @@ static int perf_rdr_read_ubuf(uint32_t rdr_num, uint64_t *buffer)
i = tentry->num_words;
while (i--) {
buffer[i] = 0;
- }
+ }

/* Check for bits an even number of 64 */
if ((xbits = width & 0x03f) != 0) {
@@ -808,18 +808,22 @@ static int perf_write_image(uint64_t *memaddr)
}

runway = ioremap_nocache(cpu_device->hpa.start, 4096);
+ if (!runway) {
+ printk(KERN_ERR "write_image: virtual mapping failed!\n");
+ return -ENOMEM;
+ }

/* Merge intrigue bits into Runway STATUS 0 */
tmp64 = __raw_readq(runway + RUNWAY_STATUS) & 0xffecfffffffffffful;
- __raw_writeq(tmp64 | (*memaddr++ & 0x0013000000000000ul),
+ __raw_writeq(tmp64 | (*memaddr++ & 0x0013000000000000ul),
runway + RUNWAY_STATUS);
-
+
/* Write RUNWAY DEBUG registers */
for (i = 0; i < 8; i++) {
__raw_writeq(*memaddr++, runway + RUNWAY_DEBUG);
}

- return 0;
+ return 0;
}

/*
@@ -843,7 +847,7 @@ static void perf_rdr_write(uint32_t rdr_num, uint64_t *buffer)
perf_rdr_shift_out_U(rdr_num, buffer[i]);
} else {
perf_rdr_shift_out_W(rdr_num, buffer[i]);
- }
+ }
}
printk("perf_rdr_write done\n");
}
--
1.9.1