Subject: Re: [PATCHv3 bpf-next 1/5] kallsyms: Fully export kallsyms_on_each_symbol function

From: Jiri Olsa <[email-masked]>
Date: Thu, 28 Apr 2022 16:06:35 +0200

On Wed, Apr 27, 2022 at 11:03:41PM +0200, Jiri Olsa wrote:
> Fully exporting kallsyms_on_each_symbol function, so it can be used
> in following changes.
> 
> Rather than adding another ifdef option let's export the function
> completely (when CONFIG_KALLSYMS option is defined).
> 
> Cc: Christoph Hellwig <[email-masked]>
> Signed-off-by: Jiri Olsa <[email-masked]>
> ---
>  include/linux/kallsyms.h | 5 +++++
>  kernel/kallsyms.c        | 2 --
>  2 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
> index ce1bd2fbf23e..d423f3cffa6d 100644
> --- a/include/linux/kallsyms.h
> +++ b/include/linux/kallsyms.h
> @@ -163,6 +163,11 @@ static inline bool kallsyms_show_value(const struct cred *cred)
>  	return false;
>  }
>  
> +static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long),
> +					  void *data)
> +{
> +	return -EOPNOTSUPP;
> +}
>  #endif /*CONFIG_KALLSYMS*/
>  
>  static inline void print_ip_sym(const char *loglvl, unsigned long ip)
> diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
> index 79f2eb617a62..fdfd308bebc4 100644
> --- a/kernel/kallsyms.c
> +++ b/kernel/kallsyms.c
> @@ -228,7 +228,6 @@ unsigned long kallsyms_lookup_name(const char *name)
>  	return module_kallsyms_lookup_name(name);
>  }
>  
> -#ifdef CONFIG_LIVEPATCH
>  /*
>   * Iterate over all symbols in vmlinux.  For symbols from modules use
>   * module_kallsyms_on_each_symbol instead.
> @@ -251,7 +250,6 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
>  	}
>  	return 0;
>  }
> -#endif /* CONFIG_LIVEPATCH */
>  
>  static unsigned long get_symbol_pos(unsigned long addr,
>  				    unsigned long *symbolsize,
> -- 
> 2.35.1
> 

got this one wrong, it needs one more change
I'll send new version

jirka

---
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index ce1bd2fbf23e..89f063651192 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -65,11 +65,11 @@ static inline void *dereference_symbol_descriptor(void *ptr)
 	return ptr;
 }
 
+#ifdef CONFIG_KALLSYMS
 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
 				      unsigned long),
 			    void *data);
 
-#ifdef CONFIG_KALLSYMS
 /* Lookup the address for a symbol. Returns 0 if not found. */
 unsigned long kallsyms_lookup_name(const char *name);
 
@@ -163,6 +163,11 @@ static inline bool kallsyms_show_value(const struct cred *cred)
 	return false;
 }
 
+static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long),
+					  void *data)
+{
+	return -EOPNOTSUPP;
+}
 #endif /*CONFIG_KALLSYMS*/
 
 static inline void print_ip_sym(const char *loglvl, unsigned long ip)
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 79f2eb617a62..fdfd308bebc4 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -228,7 +228,6 @@ unsigned long kallsyms_lookup_name(const char *name)
 	return module_kallsyms_lookup_name(name);
 }
 
-#ifdef CONFIG_LIVEPATCH
 /*
  * Iterate over all symbols in vmlinux.  For symbols from modules use
  * module_kallsyms_on_each_symbol instead.
@@ -251,7 +250,6 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
 	}
 	return 0;
 }
-#endif /* CONFIG_LIVEPATCH */
 
 static unsigned long get_symbol_pos(unsigned long addr,
 				    unsigned long *symbolsize,