powerpc/pseries/cmm: call balloon_devinfo_init() also without CONFIG_BALLOON_COMPACTION

[ Upstream commit fc6bcf9ac4de76f5e7bcd020b3c0a86faff3f2d5 ]

Patch series "powerpc/pseries/cmm: two smaller fixes".

Two smaller fixes identified while doing a bigger rework.

This patch (of 2):

We always have to initialize the balloon_dev_info, even when compaction is
not configured in: otherwise the containing list and the lock are left
uninitialized.

Likely not many such configs exist in practice, but let's CC stable to
be sure.

This was found by code inspection.

Link: https://lkml.kernel.org/r/20251021100606.148294-1-david@redhat.com
Link: https://lkml.kernel.org/r/20251021100606.148294-2-david@redhat.com
Fixes: fe030c9b85e6 ("powerpc/pseries/cmm: Implement balloon compaction")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ moved balloon_devinfo_init() call from inside cmm_balloon_compaction_init() to cmm_init() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index 45a3a3022a85c9061ed7b724c1424369f83b0ee9..6b38ccd63c90888310baed1d8ae13135fc850654 100644 (file)
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -570,7 +570,6 @@ static int cmm_balloon_compaction_init(void)
 {
        int rc;
 
-       balloon_devinfo_init(&b_dev_info);
        b_dev_info.migratepage = cmm_migratepage;
 
        balloon_mnt = kern_mount(&balloon_fs);
@@ -624,6 +623,7 @@ static int cmm_init(void)
        if (!firmware_has_feature(FW_FEATURE_CMO) && !simulate)
                return -EOPNOTSUPP;
 
+       balloon_devinfo_init(&b_dev_info);
        rc = cmm_balloon_compaction_init();
        if (rc)
                return rc;