The quilt patch titled
Subject: riscv: mm: skip pgtable level check in {pud,p4d}_alloc_one
has been removed from the -mm tree. Its filename was
riscv-mm-skip-pgtable-level-check-in-pudp4d_alloc_one.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: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Subject: riscv: mm: skip pgtable level check in {pud,p4d}_alloc_one
Date: Wed, 8 Jan 2025 14:57:18 +0800
Patch series "move pagetable_*_dtor() to __tlb_remove_table()", v5.
As proposed [1] by Peter Zijlstra below, this patch series aims to move
pagetable_*_dtor() into __tlb_remove_table(). This will cleanup
pagetable_*_dtor() a bit and more gracefully fix the UAF issue [2]
reported by syzbot.
: Notably:
:
: - s390 pud isn't calling the existing pagetable_pud_[cd]tor()
: - none of the p4d things have pagetable_p4d_[cd]tor() (x86,arm64,s390,riscv)
: and they have inconsistent accounting
: - while much of the _ctor calls are in generic code, many of the _dtor
: calls are in arch code for hysterial raisins, this could easily be
: fixed
: - if we fix ptlock_free() to handle NULL, then all the _dtor()
: functions can use it, and we can observe they're all identical
: and can be folded
:
: after all that cleanup, you can move the _dtor from *_free_tlb() into
: tlb_remove_table() -- which for the above case, would then have it called
: from __tlb_remove_table_free().
This patch (of 16):
{pmd,pud,p4d}_alloc_one() is never called if the corresponding page table
level is folded, as {pmd,pud,p4d}_alloc() already does the required check.
We can therefore remove the runtime page table level checks in
{pud,p4d}_alloc_one. The PUD helper becomes equivalent to the generic
version, so we remove it altogether.
This is consistent with the way arm64 and x86 handle this situation
(runtime check in p4d_free() only).
Link: https://lkml.kernel.org/r/cover.1736317725.git.zhengqi.arch@xxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/93a1c6bddc0ded9f1a9f15658c1e4af5c93d1194.1736317725.git.zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Alexandre Ghiti <alex@xxxxxxxx>
Cc: Andreas Larsson <andreas@xxxxxxxxxxx>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/riscv/include/asm/pgalloc.h | 22 ++++------------------
1 file changed, 4 insertions(+), 18 deletions(-)
--- a/arch/riscv/include/asm/pgalloc.h~riscv-mm-skip-pgtable-level-check-in-pudp4d_alloc_one
+++ a/arch/riscv/include/asm/pgalloc.h
@@ -12,7 +12,6 @@
#include <asm/tlb.h>
#ifdef CONFIG_MMU
-#define __HAVE_ARCH_PUD_ALLOC_ONE
#define __HAVE_ARCH_PUD_FREE
#include <asm-generic/pgalloc.h>
@@ -88,15 +87,6 @@ static inline void pgd_populate_safe(str
}
}
-#define pud_alloc_one pud_alloc_one
-static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
- if (pgtable_l4_enabled)
- return __pud_alloc_one(mm, addr);
-
- return NULL;
-}
-
#define pud_free pud_free
static inline void pud_free(struct mm_struct *mm, pud_t *pud)
{
@@ -118,15 +108,11 @@ static inline void __pud_free_tlb(struct
#define p4d_alloc_one p4d_alloc_one
static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
{
- if (pgtable_l5_enabled) {
- gfp_t gfp = GFP_PGTABLE_USER;
-
- if (mm == &init_mm)
- gfp = GFP_PGTABLE_KERNEL;
- return (p4d_t *)get_zeroed_page(gfp);
- }
+ gfp_t gfp = GFP_PGTABLE_USER;
- return NULL;
+ if (mm == &init_mm)
+ gfp = GFP_PGTABLE_KERNEL;
+ return (p4d_t *)get_zeroed_page(gfp);
}
static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)
_
Patches currently in -mm which might be from kevin.brodsky@xxxxxxx are
