Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/…

…git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

 - Arm CMN perf: fix the DTC allocation failure path which can end up
   erroneously clearing live counters

 - arm64/mm: fix hugetlb handling of the dirty page state leading to a
   continuous fault loop in user on hardware without dirty bit
   management (DBM). That's caused by the dirty+writeable information
   not being properly preserved across a series of mprotect(PROT_NONE),
   mprotect(PROT_READ|PROT_WRITE)

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mm: Always make sw-dirty PTEs hw-dirty in pte_modify
  perf/arm-cmn: Fail DTC counter allocation correctly

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;
 }
 

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;
 	}