[dpdk-dev] [PATCH] app/testpmd: fix division by zero bug

[dpdk-dev] [PATCH] app/testpmd: fix division by zero bug

[Min Hu (Connor)]

Variable total, which may be zero and result in segmentation fault.

This patch fixed it.

Fixes: 9b1249d9ff69 ("app/testpmd: support dumping socket memory")
Cc: stable@dpdk.org

Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
---
 app/test-pmd/cmdline.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
index 08da2b1..cde0a00 100644
--- a/app/test-pmd/cmdline.c
+++ b/app/test-pmd/cmdline.c
@@ -9631,6 +9631,9 @@ dump_socket_mem(FILE *f)
 			socket_stats.alloc_count,
 			socket_stats.free_count);
 	}
+
+	if (total == 0)
+		return;
 	fprintf(f,
 		"Total   : size(M) total: %.6lf alloc: %.6lf(%.3lf%%) free: %.6lf \tcount alloc: %-4u free: %u\n",
 		(double)total / (1024 * 1024), (double)alloc / (1024 * 1024),
-- 
2.7.4

Re: [dpdk-dev] [PATCH] app/testpmd: fix division by zero bug

[Ferruh Yigit]

On 4/21/2021 12:38 PM, Min Hu (Connor) wrote:
> Variable total, which may be zero and result in segmentation fault.
> 
> This patch fixed it.
> 
> Fixes: 9b1249d9ff69 ("app/testpmd: support dumping socket memory")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
> ---
>   app/test-pmd/cmdline.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
> index 08da2b1..cde0a00 100644
> --- a/app/test-pmd/cmdline.c
> +++ b/app/test-pmd/cmdline.c
> @@ -9631,6 +9631,9 @@ dump_socket_mem(FILE *f)
>   			socket_stats.alloc_count,
>   			socket_stats.free_count);
>   	}
> +
> +	if (total == 0)
> +		return;
>   	fprintf(f,
>   		"Total   : size(M) total: %.6lf alloc: %.6lf(%.3lf%%) free: %.6lf \tcount alloc: %-4u free: %u\n",
>   		(double)total / (1024 * 1024), (double)alloc / (1024 * 1024),
> 

Hi Connor,

Not sure if the value can be zero on practice, but if the issue is found via 
static analyzer tool, instead of return from function without any output what 
about following instead:

  -               (double)alloc * 100 / (double)total,
  +               total ? ((double)alloc * 100 / (double)total) : 0,

[dpdk-dev] [PATCH v2] app/testpmd: fix division by zero bug

[Min Hu (Connor)]

Variable total, which may be zero and result in segmentation fault.

This patch fixed it.

Fixes: 9b1249d9ff69 ("app/testpmd: support dumping socket memory")
Cc: stable@dpdk.org

Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
---
 app/test-pmd/cmdline.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
index 12efbc0..51d789e 100644
--- a/app/test-pmd/cmdline.c
+++ b/app/test-pmd/cmdline.c
@@ -9727,7 +9727,7 @@ dump_socket_mem(FILE *f)
 	fprintf(f,
 		"Total   : size(M) total: %.6lf alloc: %.6lf(%.3lf%%) free: %.6lf \tcount alloc: %-4u free: %u\n",
 		(double)total / (1024 * 1024), (double)alloc / (1024 * 1024),
-		(double)alloc * 100 / (double)total,
+		total ? ((double)alloc * 100 / (double)total) : 0,
 		(double)free / (1024 * 1024),
 		n_alloc, n_free);
 	if (last_allocs)
-- 
2.7.4

Re: [dpdk-dev] [PATCH] app/testpmd: fix division by zero bug

[Min Hu (Connor)]

在 2021/4/21 19:38, Min Hu (Connor) 写道:
> Variable total, which may be zero and result in segmentation fault.
> 
> This patch fixed it.
> 
> Fixes: 9b1249d9ff69 ("app/testpmd: support dumping socket memory")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
> ---
>   app/test-pmd/cmdline.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
> index 08da2b1..cde0a00 100644
> --- a/app/test-pmd/cmdline.c
> +++ b/app/test-pmd/cmdline.c
> @@ -9631,6 +9631,9 @@ dump_socket_mem(FILE *f)
>   			socket_stats.alloc_count,
>   			socket_stats.free_count);
>   	}
> +
> +	if (total == 0)
> +		return;
>   	fprintf(f,
>   		"Total   : size(M) total: %.6lf alloc: %.6lf(%.3lf%%) free: %.6lf \tcount alloc: %-4u free: %u\n",
>   		(double)total / (1024 * 1024), (double)alloc / (1024 * 1024),
> 
Agreed, fixed in v2, thanks.

Re: [dpdk-dev] [PATCH v2] app/testpmd: fix division by zero bug

[Ferruh Yigit]

On 4/26/2021 12:57 PM, Min Hu (Connor) wrote:
> Variable total, which may be zero and result in segmentation fault.
> 
> This patch fixed it.
> 
> Fixes: 9b1249d9ff69 ("app/testpmd: support dumping socket memory")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>

Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>

Applied to dpdk-next-net/main, thanks.