Re: [PATCH v2 4/5] mm: FLEXIBLE_THP for improved performance

From: kernel test robot
Date: Mon Jul 03 2023 - 11:52:24 EST

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Hi Ryan,

kernel test robot noticed the following build errors:

[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on v6.4]
[cannot apply to akpm-mm/mm-everything linus/master next-20230703]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Ryan-Roberts/mm-Non-pmd-mappable-large-folios-for-folio_add_new_anon_rmap/20230703-215627
base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
patch link: https://lore.kernel.org/r/20230703135330.1865927-5-ryan.roberts%40arm.com
patch subject: [PATCH v2 4/5] mm: FLEXIBLE_THP for improved performance
config: um-allyesconfig (https://download.01.org/0day-ci/archive/20230703/202307032325.u93xmWbG-lkp@xxxxxxxxx/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project.git f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce: (https://download.01.org/0day-ci/archive/20230703/202307032325.u93xmWbG-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307032325.u93xmWbG-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

In file included from mm/memory.c:42:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
^
In file included from mm/memory.c:42:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
In file included from mm/memory.c:42:
In file included from include/linux/kernel_stat.h:9:
In file included from include/linux/interrupt.h:11:
In file included from include/linux/hardirq.h:11:
In file included from arch/um/include/asm/hardirq.h:5:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/um/include/asm/io.h:24:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> mm/memory.c:4271:2: error: implicit declaration of function 'set_ptes' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
set_ptes(vma->vm_mm, addr, vmf->pte, entry, pgcount);
^
mm/memory.c:4271:2: note: did you mean 'set_pte'?
arch/um/include/asm/pgtable.h:232:20: note: 'set_pte' declared here
static inline void set_pte(pte_t *pteptr, pte_t pteval)
^
>> mm/memory.c:4274:2: error: implicit declaration of function 'update_mmu_cache_range' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
update_mmu_cache_range(vma, addr, vmf->pte, pgcount);
^
12 warnings and 2 errors generated.

vim +/set_ptes +4271 mm/memory.c

4135
4136 /*
4137 * We enter with non-exclusive mmap_lock (to exclude vma changes,
4138 * but allow concurrent faults), and pte mapped but not yet locked.
4139 * We return with mmap_lock still held, but pte unmapped and unlocked.
4140 */
4141 static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
4142 {
4143 bool uffd_wp = vmf_orig_pte_uffd_wp(vmf);
4144 struct vm_area_struct *vma = vmf->vma;
4145 struct folio *folio;
4146 vm_fault_t ret = 0;
4147 pte_t entry;
4148 int order;
4149 int pgcount;
4150 unsigned long addr;
4151
4152 /* File mapping without ->vm_ops ? */
4153 if (vma->vm_flags & VM_SHARED)
4154 return VM_FAULT_SIGBUS;
4155
4156 /*
4157 * Use pte_alloc() instead of pte_alloc_map(). We can't run
4158 * pte_offset_map() on pmds where a huge pmd might be created
4159 * from a different thread.
4160 *
4161 * pte_alloc_map() is safe to use under mmap_write_lock(mm) or when
4162 * parallel threads are excluded by other means.
4163 *
4164 * Here we only have mmap_read_lock(mm).
4165 */
4166 if (pte_alloc(vma->vm_mm, vmf->pmd))
4167 return VM_FAULT_OOM;
4168
4169 /* See comment in handle_pte_fault() */
4170 if (unlikely(pmd_trans_unstable(vmf->pmd)))
4171 return 0;
4172
4173 /* Use the zero-page for reads */
4174 if (!(vmf->flags & FAULT_FLAG_WRITE) &&
4175 !mm_forbids_zeropage(vma->vm_mm)) {
4176 entry = pte_mkspecial(pfn_pte(my_zero_pfn(vmf->address),
4177 vma->vm_page_prot));
4178 vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,
4179 vmf->address, &vmf->ptl);
4180 if (vmf_pte_changed(vmf)) {
4181 update_mmu_tlb(vma, vmf->address, vmf->pte);
4182 goto unlock;
4183 }
4184 ret = check_stable_address_space(vma->vm_mm);
4185 if (ret)
4186 goto unlock;
4187 /* Deliver the page fault to userland, check inside PT lock */
4188 if (userfaultfd_missing(vma)) {
4189 pte_unmap_unlock(vmf->pte, vmf->ptl);
4190 return handle_userfault(vmf, VM_UFFD_MISSING);
4191 }
4192 if (uffd_wp)
4193 entry = pte_mkuffd_wp(entry);
4194 set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry);
4195
4196 /* No need to invalidate - it was non-present before */
4197 update_mmu_cache(vma, vmf->address, vmf->pte);
4198 goto unlock;
4199 }
4200
4201 /*
4202 * If allocating a large folio, determine the biggest suitable order for
4203 * the VMA (e.g. it must not exceed the VMA's bounds, it must not
4204 * overlap with any populated PTEs, etc). We are not under the ptl here
4205 * so we will need to re-check that we are not overlapping any populated
4206 * PTEs once we have the lock.
4207 */
4208 order = uffd_wp ? 0 : max_anon_folio_order(vma);
4209 if (order > 0) {
4210 vmf->pte = pte_offset_map(vmf->pmd, vmf->address);
4211 order = calc_anon_folio_order_alloc(vmf, order);
4212 pte_unmap(vmf->pte);
4213 }
4214
4215 /* Allocate our own private folio. */
4216 if (unlikely(anon_vma_prepare(vma)))
4217 goto oom;
4218 folio = alloc_anon_folio(vma, vmf->address, order);
4219 if (!folio && order > 0) {
4220 order = 0;
4221 folio = alloc_anon_folio(vma, vmf->address, order);
4222 }
4223 if (!folio)
4224 goto oom;
4225
4226 pgcount = 1 << order;
4227 addr = ALIGN_DOWN(vmf->address, pgcount << PAGE_SHIFT);
4228
4229 if (mem_cgroup_charge(folio, vma->vm_mm, GFP_KERNEL))
4230 goto oom_free_page;
4231 folio_throttle_swaprate(folio, GFP_KERNEL);
4232
4233 /*
4234 * The memory barrier inside __folio_mark_uptodate makes sure that
4235 * preceding stores to the folio contents become visible before
4236 * the set_ptes() write.
4237 */
4238 __folio_mark_uptodate(folio);
4239
4240 entry = mk_pte(&folio->page, vma->vm_page_prot);
4241 entry = pte_sw_mkyoung(entry);
4242 if (vma->vm_flags & VM_WRITE)
4243 entry = pte_mkwrite(pte_mkdirty(entry));
4244
4245 vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, addr, &vmf->ptl);
4246 if (vmf_pte_changed(vmf)) {
4247 update_mmu_tlb(vma, vmf->address, vmf->pte);
4248 goto release;
4249 } else if (order > 0 && check_ptes_none(vmf->pte, pgcount) != pgcount) {
4250 goto release;
4251 }
4252
4253 ret = check_stable_address_space(vma->vm_mm);
4254 if (ret)
4255 goto release;
4256
4257 /* Deliver the page fault to userland, check inside PT lock */
4258 if (userfaultfd_missing(vma)) {
4259 pte_unmap_unlock(vmf->pte, vmf->ptl);
4260 folio_put(folio);
4261 return handle_userfault(vmf, VM_UFFD_MISSING);
4262 }
4263
4264 folio_ref_add(folio, pgcount - 1);
4265 add_mm_counter(vma->vm_mm, MM_ANONPAGES, pgcount);
4266 folio_add_new_anon_rmap(folio, vma, addr);
4267 folio_add_lru_vma(folio, vma);
4268
4269 if (uffd_wp)
4270 entry = pte_mkuffd_wp(entry);
> 4271 set_ptes(vma->vm_mm, addr, vmf->pte, entry, pgcount);
4272
4273 /* No need to invalidate - it was non-present before */
> 4274 update_mmu_cache_range(vma, addr, vmf->pte, pgcount);
4275 unlock:
4276 pte_unmap_unlock(vmf->pte, vmf->ptl);
4277 return ret;
4278 release:
4279 folio_put(folio);
4280 goto unlock;
4281 oom_free_page:
4282 folio_put(folio);
4283 oom:
4284 return VM_FAULT_OOM;
4285 }
4286

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Next message: Mateusz Stachyra: "[PATCH] trace: fix null pointer dereference in tracing_err_log_open()"
Previous message: Zhangjin Wu: "Re: [PATCH v5 5/5] selftests/nolibc: riscv: customize makefile for rv32"
In reply to: Ryan Roberts: "[PATCH v2 4/5] mm: FLEXIBLE_THP for improved performance"
Next in thread: kernel test robot: "Re: [PATCH v2 4/5] mm: FLEXIBLE_THP for improved performance"
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