[PATCH] powerpc/xive: fix return value of __setup handler

[PATCH] powerpc/xive: fix return value of __setup handler

[Randy Dunlap]

__setup() handlers should return 1 to obsolete_checksetup() in
init/main.c to indicate that the boot option has been handled.
A return of 0 causes the boot option/value to be listed as an Unknown
kernel parameter and added to init's (limited) argument or environment
strings. Also, error return codes don't mean anything to
obsolete_checksetup() -- only non-zero (usually 1) or zero.
So return 1 from xive_off() and xive_store_eoi_cmdline().

Fixes: 243e25112d06 ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Fixes: c21ee04f11ae ("powerpc/xive: Add a kernel parameter for StoreEOI")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
From: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Cédric Le Goater <clg@kaod.org>
Cc: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/sysdev/xive/common.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- linux-next-20220310.orig/arch/powerpc/sysdev/xive/common.c
+++ linux-next-20220310/arch/powerpc/sysdev/xive/common.c
@@ -1708,20 +1708,20 @@ __be32 *xive_queue_page_alloc(unsigned i
 static int __init xive_off(char *arg)
 {
 	xive_cmdline_disabled = true;
-	return 0;
+	return 1;
 }
 __setup("xive=off", xive_off);
 
 static int __init xive_store_eoi_cmdline(char *arg)
 {
 	if (!arg)
-		return -EINVAL;
+		return 1;
 
 	if (strncmp(arg, "off", 3) == 0) {
 		pr_info("StoreEOI disabled on kernel command line\n");
 		xive_store_eoi = false;
 	}
-	return 0;
+	return 1;
 }
 __setup("xive.store-eoi=", xive_store_eoi_cmdline);
 

Re: [PATCH] powerpc/xive: fix return value of __setup handler

[Cédric Le Goater]

On 3/13/22 07:59, Randy Dunlap wrote:
> __setup() handlers should return 1 to obsolete_checksetup() in
> init/main.c to indicate that the boot option has been handled.
> A return of 0 causes the boot option/value to be listed as an Unknown
> kernel parameter and added to init's (limited) argument or environment
> strings. Also, error return codes don't mean anything to
> obsolete_checksetup() -- only non-zero (usually 1) or zero.
> So return 1 from xive_off() and xive_store_eoi_cmdline().
> 
> Fixes: 243e25112d06 ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
> Fixes: c21ee04f11ae ("powerpc/xive: Add a kernel parameter for StoreEOI")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> From: Igor Zhbanov <i.zhbanov@omprussia.ru>
> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Cédric Le Goater <clg@kaod.org>
> Cc: Paul Mackerras <paulus@samba.org>

Reviewed-by: Cédric Le Goater <clg@kaod.org>


Thanks,

C.


> ---
>   arch/powerpc/sysdev/xive/common.c |    6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> --- linux-next-20220310.orig/arch/powerpc/sysdev/xive/common.c
> +++ linux-next-20220310/arch/powerpc/sysdev/xive/common.c
> @@ -1708,20 +1708,20 @@ __be32 *xive_queue_page_alloc(unsigned i
>   static int __init xive_off(char *arg)
>   {
>   	xive_cmdline_disabled = true;
> -	return 0;
> +	return 1;
>   }
>   __setup("xive=off", xive_off);
>   
>   static int __init xive_store_eoi_cmdline(char *arg)
>   {
>   	if (!arg)
> -		return -EINVAL;
> +		return 1;
>   
>   	if (strncmp(arg, "off", 3) == 0) {
>   		pr_info("StoreEOI disabled on kernel command line\n");
>   		xive_store_eoi = false;
>   	}
> -	return 0;
> +	return 1;
>   }
>   __setup("xive.store-eoi=", xive_store_eoi_cmdline);
>   

Re: [PATCH] powerpc/xive: fix return value of __setup handler

[Michael Ellerman]

On Sat, 12 Mar 2022 22:59:36 -0800, Randy Dunlap wrote:
> __setup() handlers should return 1 to obsolete_checksetup() in
> init/main.c to indicate that the boot option has been handled.
> A return of 0 causes the boot option/value to be listed as an Unknown
> kernel parameter and added to init's (limited) argument or environment
> strings. Also, error return codes don't mean anything to
> obsolete_checksetup() -- only non-zero (usually 1) or zero.
> So return 1 from xive_off() and xive_store_eoi_cmdline().
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/xive: fix return value of __setup handler
      https://git.kernel.org/powerpc/c/d64e3eab75a8e1e900c0fda2410a2df8893d8f85

cheers