Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [Medium] The `policy_private_has_kernel_zone()` function incorrectly skips checking `ZONE_DMA` and `ZONE_DMA32`, which causes mempolicy bypass for private nodes possessing only lower-zone memory. --
--- Patch [23]: [PATCH v5 23/36] mm/mempolicy: apply policy at the kernel zone for private-node binds --- commit 04782bb72086af5fe29a7dbf4184affd04c79df6 Author: Gregory Price <[email protected]> mm/mempolicy: apply policy at the kernel zone for private-node binds This commit introduces policy_private_has_kernel_zone() to prevent mempolicy bypass when private nodes have non-movable memory. > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 90110e9761122..e83c2c7a94c1d 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c [ ... ] > @@ -2091,6 +2091,34 @@ bool vma_policy_mof(struct vm_area_struct *vma) [ ... ] > +static bool policy_private_has_kernel_zone(const struct mempolicy *pol) > +{ > + int nid; > + > + if (!(pol->flags & MPOL_F_PRIVATE)) > + return false; > + > + for_each_node_mask(nid, pol->nodes) { > + pg_data_t *pgdat = NODE_DATA(nid); > + enum zone_type zt; > + > + if (!node_is_private(nid)) > + continue; > + for (zt = ZONE_NORMAL; zt < ZONE_MOVABLE; zt++) [Severity: Medium] Does this loop miss checking ZONE_DMA and ZONE_DMA32 by starting at ZONE_NORMAL? If a user process sets a mempolicy binding to a private NUMA node that only contains memory in ZONE_DMA or ZONE_DMA32, this loop will return false because it skips those populated lower zones. This would cause apply_policy_zone() to incorrectly raise dynamic_policy_zone to ZONE_MOVABLE, resulting in kernel allocations falling back to other system nodes and bypassing the policy intent. > + if (managed_zone(&pgdat->node_zones[zt])) > + return true; > + } > + return false; > +} -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=23
