[v1] objtool: Fix calloc call for new -Walloc-size

[PATCH] objtool: Fix calloc call for new -Walloc-size

Posted by Sam James 2 years, 1 month ago

GCC 14 introduces a new -Walloc-size included in -Wextra which errors out
like:
```
check.c: In function ‘cfi_alloc’:
check.c:294:33: error: allocation of insufficient size ‘1’ for type ‘struct cfi_state’ with size ‘320’ [-Werror=alloc-size]
  294 |         struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
      |                                 ^~~~~~
```

The calloc prototype is:
```
void *calloc(size_t nmemb, size_t size);
```

So, just swap the number of members and size arguments to match the prototype, as
we're initialising 1 struct of size `sizeof(struct ...)`. GCC then sees we're not
doing anything wrong.

Signed-off-by: Sam James <sam@gentoo.org>
---
 tools/objtool/check.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e94756e09ca9..548ec3cd7c00 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -291,7 +291,7 @@ static void init_insn_state(struct objtool_file *file, struct insn_state *state,
 
 static struct cfi_state *cfi_alloc(void)
 {
-	struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
+	struct cfi_state *cfi = calloc(1, sizeof(struct cfi_state));
 	if (!cfi) {
 		WARN("calloc failed");
 		exit(1);
-- 
2.42.1

Re: [PATCH] objtool: Fix calloc call for new -Walloc-size

Posted by Josh Poimboeuf 2 years, 1 month ago

On Tue, Nov 07, 2023 at 08:55:00PM +0000, Sam James wrote:
> GCC 14 introduces a new -Walloc-size included in -Wextra which errors out
> like:
> ```
> check.c: In function ‘cfi_alloc’:
> check.c:294:33: error: allocation of insufficient size ‘1’ for type ‘struct cfi_state’ with size ‘320’ [-Werror=alloc-size]
>   294 |         struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
>       |                                 ^~~~~~
> ```
> 
> The calloc prototype is:
> ```
> void *calloc(size_t nmemb, size_t size);
> ```
> 
> So, just swap the number of members and size arguments to match the prototype, as
> we're initialising 1 struct of size `sizeof(struct ...)`. GCC then sees we're not
> doing anything wrong.
> 
> Signed-off-by: Sam James <sam@gentoo.org>
> ---
>  tools/objtool/check.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index e94756e09ca9..548ec3cd7c00 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -291,7 +291,7 @@ static void init_insn_state(struct objtool_file *file, struct insn_state *state,
>  
>  static struct cfi_state *cfi_alloc(void)
>  {
> -	struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
> +	struct cfi_state *cfi = calloc(1, sizeof(struct cfi_state));
>  	if (!cfi) {
>  		WARN("calloc failed");
>  		exit(1);

Thanks!

Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>

Peter are you able to grab this or should I put it in my tree first?

-- 
Josh

Re: [PATCH] objtool: Fix calloc call for new -Walloc-size

Posted by Peter Zijlstra 2 years, 1 month ago

On Thu, Nov 09, 2023 at 01:40:30PM -0800, Josh Poimboeuf wrote:
> On Tue, Nov 07, 2023 at 08:55:00PM +0000, Sam James wrote:
> > GCC 14 introduces a new -Walloc-size included in -Wextra which errors out
> > like:
> > ```
> > check.c: In function ‘cfi_alloc’:
> > check.c:294:33: error: allocation of insufficient size ‘1’ for type ‘struct cfi_state’ with size ‘320’ [-Werror=alloc-size]
> >   294 |         struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
> >       |                                 ^~~~~~
> > ```
> > 
> > The calloc prototype is:
> > ```
> > void *calloc(size_t nmemb, size_t size);
> > ```
> > 
> > So, just swap the number of members and size arguments to match the prototype, as
> > we're initialising 1 struct of size `sizeof(struct ...)`. GCC then sees we're not
> > doing anything wrong.
> > 
> > Signed-off-by: Sam James <sam@gentoo.org>
> > ---
> >  tools/objtool/check.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> > index e94756e09ca9..548ec3cd7c00 100644
> > --- a/tools/objtool/check.c
> > +++ b/tools/objtool/check.c
> > @@ -291,7 +291,7 @@ static void init_insn_state(struct objtool_file *file, struct insn_state *state,
> >  
> >  static struct cfi_state *cfi_alloc(void)
> >  {
> > -	struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
> > +	struct cfi_state *cfi = calloc(1, sizeof(struct cfi_state));
> >  	if (!cfi) {
> >  		WARN("calloc failed");
> >  		exit(1);
> 
> Thanks!
> 
> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
> 
> Peter are you able to grab this or should I put it in my tree first?

Got it, thanks!

[tip: objtool/core] objtool: Fix calloc call for new -Walloc-size

Posted by tip-bot2 for Sam James 2 years, 1 month ago

The following commit has been merged into the objtool/core branch of tip:

Commit-ID:     e2e13630f93d942d02f3b3f98660228a3545c60e
Gitweb:        https://git.kernel.org/tip/e2e13630f93d942d02f3b3f98660228a3545c60e
Author:        Sam James <sam@gentoo.org>
AuthorDate:    Tue, 07 Nov 2023 20:55:00 
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 17 Nov 2023 10:54:50 +01:00

objtool: Fix calloc call for new -Walloc-size

GCC 14 introduces a new -Walloc-size included in -Wextra which errors out
like:
```
check.c: In function ‘cfi_alloc’:
check.c:294:33: error: allocation of insufficient size ‘1’ for type ‘struct cfi_state’ with size ‘320’ [-Werror=alloc-size]
  294 |         struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
      |                                 ^~~~~~
```

The calloc prototype is:
```
void *calloc(size_t nmemb, size_t size);
```

So, just swap the number of members and size arguments to match the prototype, as
we're initialising 1 struct of size `sizeof(struct ...)`. GCC then sees we're not
doing anything wrong.

Signed-off-by: Sam James <sam@gentoo.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/20231107205504.1470006-1-sam@gentoo.org
---
 tools/objtool/check.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index e94756e..548ec3c 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -291,7 +291,7 @@ static void init_insn_state(struct objtool_file *file, struct insn_state *state,
 
 static struct cfi_state *cfi_alloc(void)
 {
-	struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
+	struct cfi_state *cfi = calloc(1, sizeof(struct cfi_state));
 	if (!cfi) {
 		WARN("calloc failed");
 		exit(1);