Re: [PATCH] viafb: replace strict_strtoul to kstrtoul and check returnvalue

From: Florian Tobias Schandinat
Date: Sun Aug 07 2011 - 10:20:59 EST


Hi Wang,

On 08/07/2011 01:31 PM, stufever@xxxxxxxxx wrote:
From: Wang Shaoyan<wangshaoyan.pt@xxxxxxxxxx>

This commit replace the function strict_strtoul(becasue commit 33ee3b2e), and check the return value to avoid such warning:

drivers/video/via/viafbdev.c:1992: warning: ignoring return value of 'kstrtoul', declared with attribute warn_unused_result

well I'm not against using the new functions but if you do this change please try to have a look why those were introduced.

Signed-off-by: Wang Shaoyan<wangshaoyan.pt@xxxxxxxxxx>
---
drivers/video/via/viafbdev.c | 137 ++++++++++++++++++++++++------------------
1 files changed, 79 insertions(+), 58 deletions(-)

diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index 53aa443..5f638d6 100644
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c
@@ -1158,7 +1158,8 @@ static ssize_t viafb_dvp0_proc_write(struct file *file,
for (i = 0; i< 3; i++) {
value = strsep(&pbuf, " ");
if (value != NULL) {
- strict_strtoul(value, 0, (unsigned long *)&reg_val);
+ if (kstrtoul(value, 0, (unsigned long *)&reg_val)< 0)
+ return -EINVAL;

Ugh, the old code was ugly (casting u8* to unsigned long*) but you did not really improve it although the new functions were introduced for cases like this. You should use kstrtou8() here, I think.
It would also be nice if you could add range checks for the value entered as the behavior to -EINVAL on values > 255 but accepting too big values that are <= 255 is not very consistent. Okay, as I know that doing this right would be difficult I'll accept this patch without them or without them being 100% accurate.

DEBUG_MSG(KERN_INFO "DVP0:reg_val[%l]=:%x\n", i,
reg_val);
switch (i) {
@@ -1228,7 +1229,8 @@ static ssize_t viafb_dvp1_proc_write(struct file *file,
for (i = 0; i< 3; i++) {
value = strsep(&pbuf, " ");
if (value != NULL) {
- strict_strtoul(value, 0, (unsigned long *)&reg_val);
+ if (kstrtoul(value, 0, (unsigned long *)&reg_val)< 0)
+ return -EINVAL;

Same here.

switch (i) {
case 0:
viafb_write_reg_mask(CR9B, VIACR,
@@ -1286,7 +1288,8 @@ static ssize_t viafb_dfph_proc_write(struct file *file,
if (copy_from_user(&buf[0], buffer, length))
return -EFAULT;
buf[length - 1] = '\0'; /*Ensure end string */
- strict_strtoul(&buf[0], 0, (unsigned long *)&reg_val);
+ if (kstrtoul(&buf[0], 0, (unsigned long *)&reg_val)< 0)
+ return -EINVAL;

Same here. And the &buf[0] is somewhat misleading, can you please correct it to be just buf?

viafb_write_reg_mask(CR97, VIACR, reg_val, 0x0f);
return count;
}
@@ -1325,7 +1328,8 @@ static ssize_t viafb_dfpl_proc_write(struct file *file,
if (copy_from_user(&buf[0], buffer, length))
return -EFAULT;
buf[length - 1] = '\0'; /*Ensure end string */
- strict_strtoul(&buf[0], 0, (unsigned long *)&reg_val);
+ if (kstrtoul(&buf[0], 0, (unsigned long *)&reg_val)< 0)
+ return -EINVAL;

Same as above.

viafb_write_reg_mask(CR99, VIACR, reg_val, 0x0f);
return count;
}
@@ -1394,8 +1398,9 @@ static ssize_t viafb_vt1636_proc_write(struct file *file,
for (i = 0; i< 2; i++) {
value = strsep(&pbuf, " ");
if (value != NULL) {
- strict_strtoul(value, 0,
- (unsigned long *)&reg_val.Data);
+ if (kstrtoul(value, 0,
+ (unsigned long *)&reg_val.Data)< 0)
+ return -EINVAL;

Again this u8 thing.

switch (i) {
case 0:
reg_val.Index = 0x08;
@@ -1431,8 +1436,9 @@ static ssize_t viafb_vt1636_proc_write(struct file *file,
for (i = 0; i< 2; i++) {
value = strsep(&pbuf, " ");
if (value != NULL) {
- strict_strtoul(value, 0,
- (unsigned long *)&reg_val.Data);
+ if (kstrtoul(value, 0,
+ (unsigned long *)&reg_val.Data)< 0)
+ return -EINVAL;

And again.

switch (i) {
case 0:
reg_val.Index = 0x08;
@@ -1950,61 +1956,76 @@ static int __init viafb_setup(void)
if (!*this_opt)
continue;

- if (!strncmp(this_opt, "viafb_mode1=", 12))
+ if (!strncmp(this_opt, "viafb_mode1=", 12)) {
viafb_mode1 = kstrdup(this_opt + 12, GFP_KERNEL);
- else if (!strncmp(this_opt, "viafb_mode=", 11))
+ } else if (!strncmp(this_opt, "viafb_mode=", 11)) {
viafb_mode = kstrdup(this_opt + 11, GFP_KERNEL);
- else if (!strncmp(this_opt, "viafb_bpp1=", 11))
- strict_strtoul(this_opt + 11, 0,
- (unsigned long *)&viafb_bpp1);
- else if (!strncmp(this_opt, "viafb_bpp=", 10))
- strict_strtoul(this_opt + 10, 0,
- (unsigned long *)&viafb_bpp);
- else if (!strncmp(this_opt, "viafb_refresh1=", 15))
- strict_strtoul(this_opt + 15, 0,
- (unsigned long *)&viafb_refresh1);
- else if (!strncmp(this_opt, "viafb_refresh=", 14))
- strict_strtoul(this_opt + 14, 0,
- (unsigned long *)&viafb_refresh);
- else if (!strncmp(this_opt, "viafb_lcd_dsp_method=", 21))
- strict_strtoul(this_opt + 21, 0,
- (unsigned long *)&viafb_lcd_dsp_method);
- else if (!strncmp(this_opt, "viafb_lcd_panel_id=", 19))
- strict_strtoul(this_opt + 19, 0,
- (unsigned long *)&viafb_lcd_panel_id);
- else if (!strncmp(this_opt, "viafb_accel=", 12))
- strict_strtoul(this_opt + 12, 0,
- (unsigned long *)&viafb_accel);
- else if (!strncmp(this_opt, "viafb_SAMM_ON=", 14))
- strict_strtoul(this_opt + 14, 0,
- (unsigned long *)&viafb_SAMM_ON);
- else if (!strncmp(this_opt, "viafb_active_dev=", 17))
+ } else if (!strncmp(this_opt, "viafb_bpp1=", 11)) {
+ if (kstrtoul(this_opt + 11, 0,
+ (unsigned long *)&viafb_bpp1)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_bpp=", 10)) {
+ if (kstrtoul(this_opt + 10, 0,
+ (unsigned long *)&viafb_bpp)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_refresh1=", 15)) {
+ if (kstrtoul(this_opt + 15, 0,
+ (unsigned long *)&viafb_refresh1)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_refresh=", 14)) {
+ if (kstrtoul(this_opt + 14, 0,
+ (unsigned long *)&viafb_refresh)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_lcd_dsp_method=", 21)) {
+ if (kstrtoul(this_opt + 21, 0,
+ (unsigned long *)&viafb_lcd_dsp_method)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_lcd_panel_id=", 19)) {
+ if (kstrtoul(this_opt + 19, 0,
+ (unsigned long *)&viafb_lcd_panel_id)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_accel=", 12)) {
+ if (kstrtoul(this_opt + 12, 0,
+ (unsigned long *)&viafb_accel)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_SAMM_ON=", 14)) {
+ if (kstrtoul(this_opt + 14, 0,
+ (unsigned long *)&viafb_SAMM_ON)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_active_dev=", 17)) {
viafb_active_dev = kstrdup(this_opt + 17, GFP_KERNEL);
- else if (!strncmp(this_opt,
- "viafb_display_hardware_layout=", 30))
- strict_strtoul(this_opt + 30, 0,
- (unsigned long *)&viafb_display_hardware_layout);
- else if (!strncmp(this_opt, "viafb_second_size=", 18))
- strict_strtoul(this_opt + 18, 0,
- (unsigned long *)&viafb_second_size);
- else if (!strncmp(this_opt,
- "viafb_platform_epia_dvi=", 24))
- strict_strtoul(this_opt + 24, 0,
- (unsigned long *)&viafb_platform_epia_dvi);
- else if (!strncmp(this_opt,
- "viafb_device_lcd_dualedge=", 26))
- strict_strtoul(this_opt + 26, 0,
- (unsigned long *)&viafb_device_lcd_dualedge);
- else if (!strncmp(this_opt, "viafb_bus_width=", 16))
- strict_strtoul(this_opt + 16, 0,
- (unsigned long *)&viafb_bus_width);
- else if (!strncmp(this_opt, "viafb_lcd_mode=", 15))
- strict_strtoul(this_opt + 15, 0,
- (unsigned long *)&viafb_lcd_mode);
- else if (!strncmp(this_opt, "viafb_lcd_port=", 15))
+ } else if (!strncmp(this_opt,
+ "viafb_display_hardware_layout=", 30)) {
+ if (kstrtoul(this_opt + 30, 0,
+ (unsigned long *)&viafb_display_hardware_layout)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_second_size=", 18)) {
+ if (kstrtoul(this_opt + 18, 0,
+ (unsigned long *)&viafb_second_size)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt,
+ "viafb_platform_epia_dvi=", 24)) {
+ if ( kstrtoul(this_opt + 24, 0,
+ (unsigned long *)&viafb_platform_epia_dvi)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt,
+ "viafb_device_lcd_dualedge=", 26)) {
+ if (kstrtoul(this_opt + 26, 0,
+ (unsigned long *)&viafb_device_lcd_dualedge)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_bus_width=", 16)) {
+ if (kstrtoul(this_opt + 16, 0,
+ (unsigned long *)&viafb_bus_width)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_lcd_mode=", 15)) {
+ if (kstrtoul(this_opt + 15, 0,
+ (unsigned long *)&viafb_lcd_mode)< 0)
+ return -EINVAL;
+ } else if (!strncmp(this_opt, "viafb_lcd_port=", 15)) {
viafb_lcd_port = kstrdup(this_opt + 15, GFP_KERNEL);
- else if (!strncmp(this_opt, "viafb_dvi_port=", 15))
+ } else if (!strncmp(this_opt, "viafb_dvi_port=", 15)) {
viafb_dvi_port = kstrdup(this_opt + 15, GFP_KERNEL);
+ }
}
return 0;
}

Please try to use the correct functions (kstrtoint, ...) here too, basically you should no longer have any need for casting pointers.


Thanks,

Florian Tobias Schandinat

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