The quilt patch titled
Subject: mips: add pte_unmap() to balance pte_offset_map()
has been removed from the -mm tree. Its filename was
mips-add-pte_unmap-to-balance-pte_offset_map.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Hugh Dickins <hughd@xxxxxxxxxx>
Subject: mips: add pte_unmap() to balance pte_offset_map()
Date: Thu, 15 Jun 2023 16:02:43 -0700 (PDT)
To keep balance in future, __update_tlb() remember to pte_unmap() after
pte_offset_map(). This is an odd case, since the caller has already done
pte_offset_map_lock(), then mips forgets the address and recalculates it;
but my two naive attempts to clean that up did more harm than good.
Link: https://lkml.kernel.org/r/addfcb3-b5f4-976e-e050-a2508e589cfe@xxxxxxxxxx
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Tested-by: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Greg Ungerer <gerg@xxxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: John David Anglin <dave.anglin@xxxxxxxx>
Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Michal Simek <monstr@xxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/mips/mm/tlb-r4k.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
--- a/arch/mips/mm/tlb-r4k.c~mips-add-pte_unmap-to-balance-pte_offset_map
+++ a/arch/mips/mm/tlb-r4k.c
@@ -297,7 +297,7 @@ void __update_tlb(struct vm_area_struct
p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp;
- pte_t *ptep;
+ pte_t *ptep, *ptemap = NULL;
int idx, pid;
/*
@@ -344,7 +344,12 @@ void __update_tlb(struct vm_area_struct
} else
#endif
{
- ptep = pte_offset_map(pmdp, address);
+ ptemap = ptep = pte_offset_map(pmdp, address);
+ /*
+ * update_mmu_cache() is called between pte_offset_map_lock()
+ * and pte_unmap_unlock(), so we can assume that ptep is not
+ * NULL here: and what should be done below if it were NULL?
+ */
#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
#ifdef CONFIG_XPA
@@ -373,6 +378,9 @@ void __update_tlb(struct vm_area_struct
tlbw_use_hazard();
htw_start();
flush_micro_tlb_vm(vma);
+
+ if (ptemap)
+ pte_unmap(ptemap);
local_irq_restore(flags);
}
_
Patches currently in -mm which might be from hughd@xxxxxxxxxx are
