threads / patch / 58836

patchbuiltin: submodule--helper: Add allocation check of module_cb structure objects may be helpful in case of allocation failure

Subject: [PATCH] builtin: submodule--helper: Add allocation check of module_cb structure objects may be helpful in case of allocation failure

## tl;dr

3 messages between Nov 22, 2022 and Nov 22, 2022. Diffs are folded; open one to read it.

replies: 2people: 3as markdown or json

Li kunyu· Nov 22, 2022, 03:17 UTC · lore

The purpose of using temp is unknown, but adding an allocation failure report should be helpful.

Signed-off-by: Li kunyu <kunyu@nfschina.com>
---
 builtin/submodule--helper.c | 3 +++
 1 file changed, 3 insertions(+)

Show changes to builtin/submodule--helper.c +3 −0

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index b63f420ece..2e379623ea 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1077,6 +1077,9 @@ static void submodule_summary_callback(struct diff_queue_struct *q,
 		if (!S_ISGITLINK(p->one->mode) && !S_ISGITLINK(p->two->mode))
 			continue;
 		temp = (struct module_cb*)malloc(sizeof(struct module_cb));
+		if (!temp)
+			 BUG("The module_cb structure object fails to be allocated and the program may terminate abnormally");
+
 		temp->mod_src = p->one->mode;
 		temp->mod_dst = p->two->mode;
 		temp->oid_src = p->one->oid;

-- 
2.18.2

Junio C Hamano· Nov 22, 2022, 04:22 UTC · re: Li kunyu · lore

Re: [PATCH] builtin: submodule--helper: Add allocation check of module_cb structure objects may be helpful in case of allocation failure

Li kunyu <kunyu@nfschina.com> writes:

> The purpose of using temp is unknown, but adding an allocation failure
> report should be helpful.

Yuck.  Use of xmalloc() may be more appropriate.

Use of BUG() in a context like this is never the right thing to do. BUG() is reserved for cases where the condition should NEVER hold true in a correctly written program, and even for a correctly written program, malloc() can fail after you allocated too much memory from the heap.

Show 20 quoted lines

>
> Signed-off-by: Li kunyu <kunyu@nfschina.com>
> ---
>  builtin/submodule--helper.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index b63f420ece..2e379623ea 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -1077,6 +1077,9 @@ static void submodule_summary_callback(struct diff_queue_struct *q,
>  		if (!S_ISGITLINK(p->one->mode) && !S_ISGITLINK(p->two->mode))
>  			continue;
>  		temp = (struct module_cb*)malloc(sizeof(struct module_cb));
> +		if (!temp)
> +			 BUG("The module_cb structure object fails to be allocated and the program may terminate abnormally");
> +
>  		temp->mod_src = p->one->mode;
>  		temp->mod_dst = p->two->mode;
>  		temp->oid_src = p->one->oid;

Bagas Sanjaya· Nov 22, 2022, 08:08 UTC · re: Li kunyu · lore

Re: [PATCH] builtin: submodule--helper: Add allocation check of module_cb structure objects may be helpful in case of allocation failure

On 11/22/22 10:17, Li kunyu wrote:

> The purpose of using temp is unknown, but adding an allocation failure
> report should be helpful.
>

Don't you understand the code?

Show 16 quoted lines

> Signed-off-by: Li kunyu <kunyu@nfschina.com>
> ---
>  builtin/submodule--helper.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index b63f420ece..2e379623ea 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -1077,6 +1077,9 @@ static void submodule_summary_callback(struct diff_queue_struct *q,
>  		if (!S_ISGITLINK(p->one->mode) && !S_ISGITLINK(p->two->mode))
>  			continue;
>  		temp = (struct module_cb*)malloc(sizeof(struct module_cb));
> +		if (!temp)
> +			 BUG("The module_cb structure object fails to be allocated and the program may terminate abnormally");
> +

Why do you check whenever allocating temp is successful?

-- 
An old man doll... just what I always wanted! - Clara