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> > u32 reg, enables; > > - struct arm_smmu_cmdq_ent cmd; > > + struct arm_smmu_cmdq_ent ent; > > This shouldn't be uninitialized, we only seem to be setting ent.opcode > later in the function. Yes, that's how the existing code is. struct arm_smmu_cmdq_ent cmd; cmd.opcode = CMDQ_OP_CFGI_ALL; arm_smmu_cmdq_issue_cmd_with_sync(smmu, &cmd); cmd.opcode = CMDQ_OP_TLBI_EL2_ALL; arm_smmu_cmdq_issue_cmd_with_sync(smmu, &cmd); cmd.opcode = CMDQ_OP_TLBI_NSNH_ALL; arm_smmu_cmdq_issue_cmd_with_sync(smmu, &cmd); > Since arm_smmu_cmdq_build_cmd reads other fields > of ent to build the cmd, we are potentially sending stack garbage in ent Ah, it is tricky, it doesn't: static int arm_smmu_cmdq_build_cmd(u64 *cmd, struct arm_smmu_cmdq_ent *ent) { memset(cmd, 0, 1 << CMDQ_ENT_SZ_SHIFT); cmd[0] |= FIELD_PREP(CMDQ_0_OP, ent->opcode); switch (ent->opcode) { case CMDQ_OP_TLBI_EL2_ALL: case CMDQ_OP_TLBI_NSNH_ALL: break; [..] case CMDQ_OP_CFGI_ALL: /* Cover the entire SID range */ cmd[1] |= FIELD_PREP(CMDQ_CFGI_1_RANGE, 31); break; Only opcode is used, so it's "fine" Later patches remove ent and this trickyness so let's just leave it: /* Invalidate any cached configuration */ arm_smmu_cmdq_issue_cmd_with_sync(smmu, arm_smmu_make_cmd_cfgi_all()); /* Invalidate any stale TLB entries */ if (smmu->features & ARM_SMMU_FEAT_HYP) { arm_smmu_cmdq_issue_cmd_with_sync( smmu, arm_smmu_make_cmd_op(CMDQ_OP_TLBI_EL2_ALL)); } arm_smmu_cmdq_issue_cmd_with_sync( smmu, arm_smmu_make_cmd_op(CMDQ_OP_TLBI_NSNH_ALL)); Jason