The for loop checks whether cur_section is NULL on every iteration, but
we know it can never be NULL as there is another check towards the
bottom of the loop body. Remove this unnecessary check.
Also change i to start at 1, so that we don't need an extra +1 when we
use it.
Addresses-Coverity: 1496984 ("Null pointer dereferences)
Signed-off-by: Alex Dewar <[email protected]>
---
drivers/net/wireless/ath/ath10k/sdio.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c
index 81ddaafb6721..f31ab2ec2c48 100644
--- a/drivers/net/wireless/ath/ath10k/sdio.c
+++ b/drivers/net/wireless/ath/ath10k/sdio.c
@@ -2308,7 +2308,7 @@ static int ath10k_sdio_dump_memory_section(struct ath10k *ar,
count = 0;
- for (i = 0; cur_section; i++) {
+ for (i = 1; ; i++) {
section_size = cur_section->end - cur_section->start;
if (section_size <= 0) {
@@ -2318,7 +2318,7 @@ static int ath10k_sdio_dump_memory_section(struct ath10k *ar,
break;
}
- if ((i + 1) == mem_region->section_table.size) {
+ if (i == mem_region->section_table.size) {
/* last section */
next_section = NULL;
skip_size = 0;
--
2.28.0
On Mon, 2020-09-14 at 20:19 +0100, Alex Dewar wrote:
> The for loop checks whether cur_section is NULL on every iteration,
> but
> we know it can never be NULL as there is another check towards the
> bottom of the loop body. Remove this unnecessary check.
>
> Also change i to start at 1, so that we don't need an extra +1 wheno
> we
> use it.
>
> Addresses-Coverity: 1496984 ("Null pointer dereferences)
> Signed-off-by: Alex Dewar <[email protected]>
> ---
> drivers/net/wireless/ath/ath10k/sdio.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/sdio.c
> b/drivers/net/wireless/ath/ath10k/sdio.c
> index 81ddaafb6721..f31ab2ec2c48 100644
> --- a/drivers/net/wireless/ath/ath10k/sdio.c
> +++ b/drivers/net/wireless/ath/ath10k/sdio.c
> @@ -2308,7 +2308,7 @@ static int
> ath10k_sdio_dump_memory_section(struct ath10k *ar,
>
> count = 0;
>
> - for (i = 0; cur_section; i++) {
> + for (i = 1; ; i++) {
'i' is only referenced once inside the loop to check boundary,
the loop is actually iterating over cur_section, so i would make it
clear in the loop statement, e.g.:
Remove the break condition and the cur_section assignment at the end of
the loop and use the loop statement to do it for you
for (; cur_section; cur_section = next_section)
> section_size = cur_section->end - cur_section->start;
>
> if (section_size <= 0) {
> @@ -2318,7 +2318,7 @@ static int
> ath10k_sdio_dump_memory_section(struct ath10k *ar,
> break;
> }
>
> - if ((i + 1) == mem_region->section_table.size) {
And for i you can just increment it inline:
if (++i == ...)
> + if (i == mem_region->section_table.size) {
> /* last section */
> next_section = NULL;
> skip_size = 0;
The for loop checks whether cur_section is NULL on every iteration, but
we know it can never be NULL as there is another check towards the
bottom of the loop body. Refactor to avoid this unnecessary check.
Also, increment the variable i inline for clarity
Addresses-Coverity: 1496984 ("Null pointer dereferences)
Suggested-by: Saeed Mahameed <[email protected]>
Signed-off-by: Alex Dewar <[email protected]>
---
v2: refactor in the manner suggested by Saeed
drivers/net/wireless/ath/ath10k/sdio.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c
index 81ddaafb6721..486886c74e6a 100644
--- a/drivers/net/wireless/ath/ath10k/sdio.c
+++ b/drivers/net/wireless/ath/ath10k/sdio.c
@@ -2307,8 +2307,8 @@ static int ath10k_sdio_dump_memory_section(struct ath10k *ar,
}
count = 0;
-
- for (i = 0; cur_section; i++) {
+ i = 0;
+ for (; cur_section; cur_section = next_section) {
section_size = cur_section->end - cur_section->start;
if (section_size <= 0) {
@@ -2318,7 +2318,7 @@ static int ath10k_sdio_dump_memory_section(struct ath10k *ar,
break;
}
- if ((i + 1) == mem_region->section_table.size) {
+ if (++i == mem_region->section_table.size) {
/* last section */
next_section = NULL;
skip_size = 0;
@@ -2361,12 +2361,6 @@ static int ath10k_sdio_dump_memory_section(struct ath10k *ar,
}
count += skip_size;
-
- if (!next_section)
- /* this was the last section */
- break;
-
- cur_section = next_section;
}
return count;
--
2.28.0
Hi Alex,
On Thu, Sep 17, 2020 at 3:09 AM Alex Dewar <[email protected]> wrote:
>
> The for loop checks whether cur_section is NULL on every iteration, but
> we know it can never be NULL as there is another check towards the
> bottom of the loop body. Refactor to avoid this unnecessary check.
>
> Also, increment the variable i inline for clarity
Comments below.
> Addresses-Coverity: 1496984 ("Null pointer dereferences)
> Suggested-by: Saeed Mahameed <[email protected]>
> Signed-off-by: Alex Dewar <[email protected]>
> ---
> v2: refactor in the manner suggested by Saeed
>
> drivers/net/wireless/ath/ath10k/sdio.c | 12 +++---------
> 1 file changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c
> index 81ddaafb6721..486886c74e6a 100644
> --- a/drivers/net/wireless/ath/ath10k/sdio.c
> +++ b/drivers/net/wireless/ath/ath10k/sdio.c
> @@ -2307,8 +2307,8 @@ static int ath10k_sdio_dump_memory_section(struct ath10k *ar,
> }
>
> count = 0;
> -
> - for (i = 0; cur_section; i++) {
> + i = 0;
> + for (; cur_section; cur_section = next_section) {
You can have multiple statements in each section of a for() if you need to, e.g.
for (i = 1; cur_section; cur_section = next_section, i++) {
which means that the increment of i isn't hidden deep in the function body.
That said, this function is a mess. Something (approximately) like
this might be more readable:
prev_end = memregion->start;
for (i = 0; i < mem_region->section_table.size; i++) {
cur_section = &mem_region->section_table.sections[i];
// fail if prev_end is greater than cur_section->start - message
from line 2329 and 2294
// check section size - from line 2315
skip_size = cur_section->start - prev_end;
// check buffer size - from line 2339 - needs to account for the
skip size too.
// fill in the skip size amount - from line 2358 and 2304
// ath10k_sdio_read_mem - from line 2346
prev_end = cur_section->end;
}
Thanks,
--
Julian Calaby
Email: [email protected]
Profile: http://www.google.com/profiles/julian.calaby/
Alex Dewar <[email protected]> writes:
>> I agree. Anyone can come up with a patch?
>
> Hi Kalle,
>
> I was thinking of having a go at this. Have you applied the v2 of this
> patch yet though? I couldn't see it in wireless-drivers-next. I just
> don't want to have to rebase the patch if you were going to apply this
> v2.
I have not applied this yet. It's in my pending branch but I can easily
drop it. Just let me know what you prefer.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Alex Dewar <[email protected]> wrote:
> The for loop checks whether cur_section is NULL on every iteration, but
> we know it can never be NULL as there is another check towards the
> bottom of the loop body. Refactor to avoid this unnecessary check.
>
> Also, increment the variable i inline for clarity
>
> Addresses-Coverity: 1496984 ("Null pointer dereferences)
> Suggested-by: Saeed Mahameed <[email protected]>
> Signed-off-by: Alex Dewar <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>
Patch applied to ath-next branch of ath.git, thanks.
dbeb101d28eb ath10k: sdio: remove redundant check in for loop
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches