Make mce_gen_pool_create() return explicit error codes for better
readability.

No functional changes intended.

Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
---
Changes in v3:
  - Collect "Reviewed-by:" from Nikolay & Sohil.
  - Move the 'int ret' along with the other int variables (Sohil).

Changes in v2:
 - Collect "Reviewed-by:" from Tony.

 arch/x86/kernel/cpu/mce/genpool.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/genpool.c b/arch/x86/kernel/cpu/mce/genpool.c
index 4284749ec803..64dffb50335a 100644
--- a/arch/x86/kernel/cpu/mce/genpool.c
+++ b/arch/x86/kernel/cpu/mce/genpool.c
@@ -118,22 +118,21 @@ int mce_gen_pool_add(struct mce *mce)
 
 static int mce_gen_pool_create(void)
 {
-	int mce_numrecords, mce_poolsz, order;
+	int mce_numrecords, mce_poolsz, order, ret;
 	struct gen_pool *gpool;
-	int ret = -ENOMEM;
 	void *mce_pool;
 
 	order = order_base_2(sizeof(struct mce_evt_llist));
 	gpool = gen_pool_create(order, -1);
 	if (!gpool)
-		return ret;
+		return -ENOMEM;
 
 	mce_numrecords = max(MCE_MIN_ENTRIES, num_possible_cpus() * MCE_PER_CPU);
 	mce_poolsz = mce_numrecords * (1 << order);
 	mce_pool = kmalloc(mce_poolsz, GFP_KERNEL);
 	if (!mce_pool) {
 		gen_pool_destroy(gpool);
-		return ret;
+		return -ENOMEM;
 	}
 	ret = gen_pool_add(gpool, (unsigned long)mce_pool, mce_poolsz, -1);
 	if (ret) {
@@ -144,7 +143,7 @@ static int mce_gen_pool_create(void)
 
 	mce_evt_pool = gpool;
 
-	return ret;
+	return 0;
 }
 
 int mce_gen_pool_init(void)
-- 
2.17.1

On Fri, Oct 25, 2024 at 10:45:57AM +0800, Qiuxu Zhuo wrote:
>  	mce_numrecords = max(MCE_MIN_ENTRIES, num_possible_cpus() * MCE_PER_CPU);
>  	mce_poolsz = mce_numrecords * (1 << order);
>  	mce_pool = kmalloc(mce_poolsz, GFP_KERNEL);
>  	if (!mce_pool) {
>  		gen_pool_destroy(gpool);
> -		return ret;
> +		return -ENOMEM;

This patch is just silly: the function is not that huge not to be able to see
at a quick glance that it is -ENOMEM that is being returned in all error cases
...

>  	}
>  	ret = gen_pool_add(gpool, (unsigned long)mce_pool, mce_poolsz, -1);
>  	if (ret) {

... except in this case where, oh well, actually, it is -ENOMEM again but you
have to go down the bowells of genalloc to see it.

All in all, this is causing more churn than actually improving something...

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette