[PATCH] util: Add own prototype for __clone2() on ia64

[PATCH] util: Add own prototype for __clone2() on ia64

[Stefano Brivio]

ia64 needs to use __clone2() as clone() is not available, but glibc
doesn't export the prototype. Take it from clone(2) to avoid an
implicit declaration:

util.c: In function ‘do_clone’:
util.c:512:16: warning: implicit declaration of function ‘__clone2’ [-Wimplicit-function-declaration]
  512 |         return __clone2(fn, stack_area + stack_size / 2, stack_size / 2,
      |                ^~~~~~~~

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 util.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/util.c b/util.c
index c5ee1c0..799173f 100644
--- a/util.c
+++ b/util.c
@@ -495,6 +495,15 @@ int write_file(const char *path, const char *buf)
 	return len == 0 ? 0 : -1;
 }
 
+#ifdef __ia64__
+/* Needed by do_clone() below: glibc doesn't export the prototype of __clone2(),
+ * use the description from clone(2).
+ */
+int __clone2(int (*fn)(void *), void *stack_base, size_t stack_size, int flags,
+	     void *arg, ... /* pid_t *parent_tid, struct user_desc *tls,
+	     pid_t *child_tid */ );
+#endif
+
 /**
  * do_clone() - Wrapper of __clone2() for ia64, clone() for other architectures
  * @fn:		Entry point for child
-- 
@@ -495,6 +495,15 @@ int write_file(const char *path, const char *buf)
 	return len == 0 ? 0 : -1;
 }
 
+#ifdef __ia64__
+/* Needed by do_clone() below: glibc doesn't export the prototype of __clone2(),
+ * use the description from clone(2).
+ */
+int __clone2(int (*fn)(void *), void *stack_base, size_t stack_size, int flags,
+	     void *arg, ... /* pid_t *parent_tid, struct user_desc *tls,
+	     pid_t *child_tid */ );
+#endif
+
 /**
  * do_clone() - Wrapper of __clone2() for ia64, clone() for other architectures
  * @fn:		Entry point for child
-- 
2.39.1

Re: [PATCH] util: Add own prototype for __clone2() on ia64

[David Gibson]

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On Mon, Feb 27, 2023 at 05:50:51PM +0100, Stefano Brivio wrote:
> ia64 needs to use __clone2() as clone() is not available, but glibc
> doesn't export the prototype. Take it from clone(2) to avoid an
> implicit declaration:
> 
> util.c: In function ‘do_clone’:
> util.c:512:16: warning: implicit declaration of function ‘__clone2’ [-Wimplicit-function-declaration]
>   512 |         return __clone2(fn, stack_area + stack_size / 2, stack_size / 2,
>       |                ^~~~~~~~
> 
> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  util.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/util.c b/util.c
> index c5ee1c0..799173f 100644
> --- a/util.c
> +++ b/util.c
> @@ -495,6 +495,15 @@ int write_file(const char *path, const char *buf)
>  	return len == 0 ? 0 : -1;
>  }
>  
> +#ifdef __ia64__
> +/* Needed by do_clone() below: glibc doesn't export the prototype of __clone2(),
> + * use the description from clone(2).
> + */
> +int __clone2(int (*fn)(void *), void *stack_base, size_t stack_size, int flags,
> +	     void *arg, ... /* pid_t *parent_tid, struct user_desc *tls,
> +	     pid_t *child_tid */ );
> +#endif
> +
>  /**
>   * do_clone() - Wrapper of __clone2() for ia64, clone() for other architectures
>   * @fn:		Entry point for child

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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