[SRU,Xenial,1/1] powerpc/fadump: Return error when fadump registration fails

From: Michal Suchanek <msuchanek@suse.de>

BugLink: https://bugs.launchpad.net/bugs/1795662

 - log an error message when registration fails and no error code listed
   in the switch is returned
 - translate the hv error code to posix error code and return it from
   fw_register
 - return the posix error code from fw_register to the process writing
   to sysfs
 - return EEXIST on re-registration
 - return success on deregistration when fadump is not registered
 - return ENODEV when no memory is reserved for fadump

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Tested-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Use pr_err() to shrink the error print]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(backported from commit 98b8cd7f75643e0a442d7a4c1cef2c9d53b7e92b)
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
---
 arch/powerpc/kernel/fadump.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

On 02.10.2018 16:11, Kleber Sacilotto de Souza wrote:
> From: Michal Suchanek <msuchanek@suse.de>
> 
> BugLink: https://bugs.launchpad.net/bugs/1795662
> 
>  - log an error message when registration fails and no error code listed
>    in the switch is returned
>  - translate the hv error code to posix error code and return it from
>    fw_register
>  - return the posix error code from fw_register to the process writing
>    to sysfs
>  - return EEXIST on re-registration
>  - return success on deregistration when fadump is not registered
>  - return ENODEV when no memory is reserved for fadump
> 
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> Tested-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
> [mpe: Use pr_err() to shrink the error print]
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> (backported from commit 98b8cd7f75643e0a442d7a4c1cef2c9d53b7e92b)
> Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
> ---
>  arch/powerpc/kernel/fadump.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
> index 4e71df4048a9..6c217b931ccb 100644
> --- a/arch/powerpc/kernel/fadump.c
> +++ b/arch/powerpc/kernel/fadump.c
> @@ -360,9 +360,9 @@ static int __init early_fadump_reserve_mem(char *p)
>  }
>  early_param("fadump_reserve_mem", early_fadump_reserve_mem);
>  
> -static void register_fw_dump(struct fadump_mem_struct *fdm)
> +static int register_fw_dump(struct fadump_mem_struct *fdm)
>  {
> -	int rc;
> +	int rc, err;
>  	unsigned int wait_time;
>  
>  	pr_debug("Registering for firmware-assisted kernel dump...\n");
> @@ -379,7 +379,11 @@ static void register_fw_dump(struct fadump_mem_struct *fdm)
>  
>  	} while (wait_time);
>  
> +	err = -EIO;
>  	switch (rc) {
> +	default:
> +		pr_err("Failed to register. Unknown Error(%d).\n", rc);
> +		break;
>  	case -1:
>  		printk(KERN_ERR "Failed to register firmware-assisted kernel"
>  			" dump. Hardware Error(%d).\n", rc);
> @@ -387,18 +391,22 @@ static void register_fw_dump(struct fadump_mem_struct *fdm)
>  	case -3:
>  		printk(KERN_ERR "Failed to register firmware-assisted kernel"
>  			" dump. Parameter Error(%d).\n", rc);
> +		err = -EINVAL;
>  		break;
>  	case -9:
>  		printk(KERN_ERR "firmware-assisted kernel dump is already "
>  			" registered.");
>  		fw_dump.dump_registered = 1;
> +		err = -EEXIST;
>  		break;
>  	case 0:
>  		printk(KERN_INFO "firmware-assisted kernel dump registration"
>  			" is successful\n");
>  		fw_dump.dump_registered = 1;
> +		err = 0;
>  		break;
>  	}
> +	return err;
>  }
>  
>  void crash_fadump(struct pt_regs *regs, const char *str)
> @@ -997,7 +1005,7 @@ static unsigned long init_fadump_header(unsigned long addr)
>  	return addr;
>  }
>  
> -static void register_fadump(void)
> +static int register_fadump(void)
>  {
>  	unsigned long addr;
>  	void *vaddr;
> @@ -1008,7 +1016,7 @@ static void register_fadump(void)
>  	 * assisted dump.
>  	 */
>  	if (!fw_dump.reserve_dump_area_size)
> -		return;
> +		return -ENODEV;
>  
>  	ret = fadump_setup_crash_memory_ranges();
>  	if (ret)
> @@ -1023,7 +1031,7 @@ static void register_fadump(void)
>  	fadump_create_elfcore_headers(vaddr);
>  
>  	/* register the future kernel dump with firmware. */
> -	register_fw_dump(&fdm);
> +	return register_fw_dump(&fdm);
>  }
>  
>  static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
> @@ -1208,7 +1216,6 @@ static ssize_t fadump_register_store(struct kobject *kobj,
>  	switch (buf[0]) {
>  	case '0':
>  		if (fw_dump.dump_registered == 0) {
> -			ret = -EINVAL;
>  			goto unlock_out;
>  		}
>  		/* Un-register Firmware-assisted dump */
> @@ -1216,11 +1223,11 @@ static ssize_t fadump_register_store(struct kobject *kobj,
>  		break;
>  	case '1':
>  		if (fw_dump.dump_registered == 1) {
> -			ret = -EINVAL;
> +			ret = -EEXIST;
>  			goto unlock_out;
>  		}
>  		/* Register Firmware-assisted dump */
> -		register_fadump();
> +		ret = register_fadump();
>  		break;
>  	default:
>  		ret = -EINVAL;
>