[PATCH v2 2/4] powerpc/rtas: make all exports GPL

[Laurent Dufour]

On 24/01/2023 15:04:46, Nathan Lynch wrote:
> The first symbol exports of RTAS functions and data came with the (now
> removed) scanlog driver in 2003:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=f92e361842d5251e50562b09664082dcbd0548bb
> 
> At the time this was applied, EXPORT_SYMBOL_GPL() was very new, and
> the exports of rtas_call() etc have remained non-GPL. As new APIs have
> been added to the RTAS subsystem, their symbol exports have followed
> the convention set by existing code.
> 
> However, the historical evidence is that RTAS function exports have
> been added over time only to satisfy the needs of in-kernel users, and
> these clients must have fairly intimate knowledge of how the APIs work
> to use them safely. No out of tree users are known, and future ones
> seem unlikely.
> 
> Arguably the default for RTAS symbols should have become
> EXPORT_SYMBOL_GPL once it was available. Let's make it so now, and
> exceptions can be evaluated as needed.

I also think this is unlikely to happen. But in the case a non GPL driver
needs one of this symbol, I guess it will be hard to move backward once it
is upstream. Crossing fingers!

Reviewed-by: Laurent Dufour <laurent.dufour at fr.ibm.com>

> 
> Signed-off-by: Nathan Lynch <nathanl at linux.ibm.com>
> ---
>  arch/powerpc/kernel/rtas.c | 30 +++++++++++++++---------------
>  1 file changed, 15 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
> index 6c5716b19d69..e60e2f5af7b9 100644
> --- a/arch/powerpc/kernel/rtas.c
> +++ b/arch/powerpc/kernel/rtas.c
> @@ -65,10 +65,10 @@ struct rtas_t rtas = {
>  };
>  
>  DEFINE_SPINLOCK(rtas_data_buf_lock);
> -EXPORT_SYMBOL(rtas_data_buf_lock);
> +EXPORT_SYMBOL_GPL(rtas_data_buf_lock);
>  
>  char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
> -EXPORT_SYMBOL(rtas_data_buf);
> +EXPORT_SYMBOL_GPL(rtas_data_buf);
>  
>  unsigned long rtas_rmo_buf;
>  
> @@ -77,7 +77,7 @@ unsigned long rtas_rmo_buf;
>   * This is done like this so rtas_flash can be a module.
>   */
>  void (*rtas_flash_term_hook)(int);
> -EXPORT_SYMBOL(rtas_flash_term_hook);
> +EXPORT_SYMBOL_GPL(rtas_flash_term_hook);
>  
>  /* RTAS use home made raw locking instead of spin_lock_irqsave
>   * because those can be called from within really nasty contexts
> @@ -325,7 +325,7 @@ void rtas_progress(char *s, unsigned short hex)
>   
>  	spin_unlock(&progress_lock);
>  }
> -EXPORT_SYMBOL(rtas_progress);		/* needed by rtas_flash module */
> +EXPORT_SYMBOL_GPL(rtas_progress);		/* needed by rtas_flash module */
>  
>  int rtas_token(const char *service)
>  {
> @@ -335,13 +335,13 @@ int rtas_token(const char *service)
>  	tokp = of_get_property(rtas.dev, service, NULL);
>  	return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
>  }
> -EXPORT_SYMBOL(rtas_token);
> +EXPORT_SYMBOL_GPL(rtas_token);
>  
>  int rtas_service_present(const char *service)
>  {
>  	return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
>  }
> -EXPORT_SYMBOL(rtas_service_present);
> +EXPORT_SYMBOL_GPL(rtas_service_present);
>  
>  #ifdef CONFIG_RTAS_ERROR_LOGGING
>  
> @@ -356,7 +356,7 @@ int rtas_get_error_log_max(void)
>  {
>  	return rtas_error_log_max;
>  }
> -EXPORT_SYMBOL(rtas_get_error_log_max);
> +EXPORT_SYMBOL_GPL(rtas_get_error_log_max);
>  
>  static void __init init_error_log_max(void)
>  {
> @@ -584,7 +584,7 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...)
>  	}
>  	return ret;
>  }
> -EXPORT_SYMBOL(rtas_call);
> +EXPORT_SYMBOL_GPL(rtas_call);
>  
>  /**
>   * rtas_busy_delay_time() - From an RTAS status value, calculate the
> @@ -622,7 +622,7 @@ unsigned int rtas_busy_delay_time(int status)
>  
>  	return ms;
>  }
> -EXPORT_SYMBOL(rtas_busy_delay_time);
> +EXPORT_SYMBOL_GPL(rtas_busy_delay_time);
>  
>  /**
>   * rtas_busy_delay() - helper for RTAS busy and extended delay statuses
> @@ -696,7 +696,7 @@ bool rtas_busy_delay(int status)
>  
>  	return ret;
>  }
> -EXPORT_SYMBOL(rtas_busy_delay);
> +EXPORT_SYMBOL_GPL(rtas_busy_delay);
>  
>  static int rtas_error_rc(int rtas_rc)
>  {
> @@ -741,7 +741,7 @@ int rtas_get_power_level(int powerdomain, int *level)
>  		return rtas_error_rc(rc);
>  	return rc;
>  }
> -EXPORT_SYMBOL(rtas_get_power_level);
> +EXPORT_SYMBOL_GPL(rtas_get_power_level);
>  
>  int rtas_set_power_level(int powerdomain, int level, int *setlevel)
>  {
> @@ -759,7 +759,7 @@ int rtas_set_power_level(int powerdomain, int level, int *setlevel)
>  		return rtas_error_rc(rc);
>  	return rc;
>  }
> -EXPORT_SYMBOL(rtas_set_power_level);
> +EXPORT_SYMBOL_GPL(rtas_set_power_level);
>  
>  int rtas_get_sensor(int sensor, int index, int *state)
>  {
> @@ -777,7 +777,7 @@ int rtas_get_sensor(int sensor, int index, int *state)
>  		return rtas_error_rc(rc);
>  	return rc;
>  }
> -EXPORT_SYMBOL(rtas_get_sensor);
> +EXPORT_SYMBOL_GPL(rtas_get_sensor);
>  
>  int rtas_get_sensor_fast(int sensor, int index, int *state)
>  {
> @@ -820,7 +820,7 @@ bool rtas_indicator_present(int token, int *maxindex)
>  
>  	return false;
>  }
> -EXPORT_SYMBOL(rtas_indicator_present);
> +EXPORT_SYMBOL_GPL(rtas_indicator_present);
>  
>  int rtas_set_indicator(int indicator, int index, int new_value)
>  {
> @@ -838,7 +838,7 @@ int rtas_set_indicator(int indicator, int index, int new_value)
>  		return rtas_error_rc(rc);
>  	return rc;
>  }
> -EXPORT_SYMBOL(rtas_set_indicator);
> +EXPORT_SYMBOL_GPL(rtas_set_indicator);
>  
>  /*
>   * Ignoring RTAS extended delay