Merge branch 'for-next/fixes' into for-next/core

Merge in arm64 fixes queued for 6.7 so that kpti_install_ng_mappings()
can be updated to use arm64_kernel_unmapped_at_el0() instead of checking
the ARM64_UNMAP_KERNEL_AT_EL0 CPU capability directly.

* for-next/fixes:
  arm64: mm: Always make sw-dirty PTEs hw-dirty in pte_modify
  perf/arm-cmn: Fail DTC counter allocation correctly
  arm64: Avoid enabling KPTI unnecessarily

Author: willdeacon

arch/arm64/include/asm/pgtable.h

@@ -834,6 +834,12 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 		pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
 
 	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
+	/*
+	 * If we end up clearing hw dirtiness for a sw-dirty PTE, set hardware
+	 * dirtiness again.
+	 */
+	if (pte_sw_dirty(pte))
+		pte = pte_mkdirty(pte);
 	return pte;
 }
 

arch/arm64/kernel/cpufeature.c

@@ -1843,6 +1843,10 @@ static int __init __kpti_install_ng_mappings(void *__unused)
 
 static void __init kpti_install_ng_mappings(void)
 {
+	/* Check whether KPTI is going to be used */
+	if (!arm64_kernel_unmapped_at_el0())
+		return;
+
 	/*
 	 * We don't need to rewrite the page-tables if either we've done
 	 * it already or we have KASLR enabled and therefore have not

drivers/perf/arm-cmn.c

@@ -1816,7 +1816,7 @@ static int arm_cmn_event_add(struct perf_event *event, int flags)
 			idx = 0;
 			while (cmn->dtc[j].counters[idx])
 				if (++idx == CMN_DT_NUM_COUNTERS)
-					goto free_dtms;
+					return -ENOSPC;
 		}
 		hw->dtc_idx[j] = idx;
 	}