| Message ID | 20240830084117.4079805-3-dev.jain@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Do not shatter hugezeropage on wp-fault | expand |
Hello,
kernel test robot noticed "BUG:sleeping_function_called_from_invalid_context_at_mm/memory.c" on:
commit: c636ba74f021bfe8d72845f9e53ee2b8ea16f5f8 ("[PATCH 2/2] mm: Allocate THP on hugezeropage wp-fault")
url: https://github.com/intel-lab-lkp/linux/commits/Dev-Jain/mm-Abstract-THP-allocation/20240830-164300
base: https://git.kernel.org/cgit/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/all/20240830084117.4079805-3-dev.jain@arm.com/
patch subject: [PATCH 2/2] mm: Allocate THP on hugezeropage wp-fault
in testcase: trinity
version: trinity-i386-abe9de86-1_20230429
with following parameters:
runtime: 600s
compiler: gcc-12
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
(please refer to attached dmesg/kmsg for entire log/backtrace)
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 <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202409031602.14479174-lkp@intel.com
[ 189.202955][T15284] BUG: sleeping function called from invalid context at mm/memory.c:6690
[ 189.203611][T15284] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 15284, name: trinity-c6
[ 189.204103][T15284] preempt_count: 1, expected: 0
[ 189.204364][T15284] RCU nest depth: 0, expected: 0
[ 189.204630][T15284] 2 locks held by trinity-c6/15284:
[189.204909][T15284] #0: ffff888164fc27b0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma (arch/x86/include/asm/atomic.h:23 include/linux/atomic/atomic-arch-fallback.h:457 include/linux/jump_label.h:261 include/linux/jump_label.h:273 include/linux/mmap_lock.h:35 include/linux/mmap_lock.h:164 mm/memory.c:6067 mm/memory.c:6127)
[189.205536][T15284] #1: ffff888160945c48 (ptlock_ptr(ptdesc)){+.+.}-{2:2}, at: do_huge_pmd_wp_page (mm/huge_memory.c:1816 mm/huge_memory.c:1838)
[ 189.206099][T15284] CPU: 1 UID: 65534 PID: 15284 Comm: trinity-c6 Not tainted 6.11.0-rc4-00551-gc636ba74f021 #1
[ 189.206657][T15284] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 189.207205][T15284] Call Trace:
[ 189.207389][T15284] <TASK>
[189.207552][T15284] dump_stack_lvl (lib/dump_stack.c:122)
[189.207803][T15284] __might_resched (kernel/sched/core.c:8462)
[189.208106][T15284] ? __pfx___might_resched (kernel/sched/core.c:8416)
[189.208397][T15284] folio_zero_user (include/linux/kernel.h:73 mm/memory.c:6690 mm/memory.c:6767)
[189.208657][T15284] thp_fault_alloc (include/linux/page-flags.h:785 (discriminator 2) mm/huge_memory.c:1156 (discriminator 2))
[189.208914][T15284] do_huge_pmd_wp_page (mm/huge_memory.c:1792 mm/huge_memory.c:1818 mm/huge_memory.c:1838)
[189.209197][T15284] ? __lock_release+0x3fe/0x860
[189.209494][T15284] ? __pfx_do_huge_pmd_wp_page (mm/huge_memory.c:1826)
[189.209802][T15284] __handle_mm_fault (mm/memory.c:5614 mm/memory.c:5852)
[189.210072][T15284] ? mt_find (lib/maple_tree.c:6961)
[189.210303][T15284] ? __pfx___handle_mm_fault (mm/memory.c:5771)
[189.210595][T15284] ? __pfx_mt_find (lib/maple_tree.c:6927)
[189.210875][T15284] handle_mm_fault (mm/memory.c:6042)
[189.211134][T15284] ? __pfx_handle_mm_fault (mm/memory.c:5997)
[189.211424][T15284] ? down_read_trylock (kernel/locking/rwsem.c:1568)
[189.211701][T15284] ? lock_mm_and_find_vma (mm/memory.c:6130)
[189.211997][T15284] do_user_addr_fault (arch/x86/mm/fault.c:1391)
[189.212283][T15284] exc_page_fault (arch/x86/include/asm/irqflags.h:26 arch/x86/include/asm/irqflags.h:87 arch/x86/include/asm/irqflags.h:147 arch/x86/mm/fault.c:1489 arch/x86/mm/fault.c:1539)
[189.212539][T15284] asm_exc_page_fault (arch/x86/include/asm/idtentry.h:623)
[189.212811][T15284] RIP: 0010:__put_user_4 (arch/x86/lib/putuser.S:88)
[ 189.213091][T15284] Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 1f 00 <89> 01 31 c9 0f 1f 00 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90
All code
========
0: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
7: 00
8: 90 nop
9: 90 nop
a: 90 nop
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: f3 0f 1e fa endbr64
1d: 48 89 cb mov %rcx,%rbx
20: 48 c1 fb 3f sar $0x3f,%rbx
24: 48 09 d9 or %rbx,%rcx
27: 0f 1f 00 nopl (%rax)
2a:* 89 01 mov %eax,(%rcx) <-- trapping instruction
2c: 31 c9 xor %ecx,%ecx
2e: 0f 1f 00 nopl (%rax)
31: c3 ret
32: cc int3
33: cc int3
34: cc int3
35: cc int3
36: 0f 1f 00 nopl (%rax)
39: 90 nop
3a: 90 nop
3b: 90 nop
3c: 90 nop
3d: 90 nop
3e: 90 nop
3f: 90 nop
Code starting with the faulting instruction
===========================================
0: 89 01 mov %eax,(%rcx)
2: 31 c9 xor %ecx,%ecx
4: 0f 1f 00 nopl (%rax)
7: c3 ret
8: cc int3
9: cc int3
a: cc int3
b: cc int3
c: 0f 1f 00 nopl (%rax)
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
[ 189.214257][T15284] RSP: 0000:ffff88812fc0fd70 EFLAGS: 00010206
[ 189.214726][T15284] RAX: 0000000020080522 RBX: 0000000000000000 RCX: 00000000ff7fffff
[ 189.215167][T15284] RDX: 1ffff1102bfd712e RSI: 1ffff11075e09456 RDI: ffff88815feb8970
[ 189.215605][T15284] RBP: 00000000ff7fffff R08: ffff88815feb8978 R09: fffffbfff50eecad
[ 189.216059][T15284] R10: ffffffffa877656f R11: 0000000000000000 R12: 1ffff11025f81faf
[ 189.216637][T15284] R13: ffff88812fc0fe30 R14: 00000000000000b9 R15: 0000000000000000
[189.217074][T15284] cap_validate_magic (kernel/capability.c:94)
[189.217349][T15284] ? __pfx_cap_validate_magic (kernel/capability.c:76)
[189.217654][T15284] __do_sys_capset (kernel/capability.c:230)
[189.217925][T15284] ? __pfx___do_sys_capset (kernel/capability.c:221)
[189.218226][T15284] do_int80_emulation (arch/x86/entry/common.c:165 arch/x86/entry/common.c:253)
[189.218497][T15284] asm_int80_emulation (arch/x86/include/asm/idtentry.h:626)
[ 189.218871][T15284] RIP: 0023:0xf7f30092
[ 189.219200][T15284] Code: 00 00 00 e9 90 ff ff ff ff a3 24 00 00 00 68 30 00 00 00 e9 80 ff ff ff ff a3 f8 ff ff ff 66 90 00 00 00 00 00 00 00 00 cd 80 <c3> 8d b4 26 00 00 00 00 8d b6 00 00 00 00 8b 1c 24 c3 8d b4 26 00
All code
========
0: 00 00 add %al,(%rax)
2: 00 e9 add %ch,%cl
4: 90 nop
5: ff (bad)
6: ff (bad)
7: ff (bad)
8: ff a3 24 00 00 00 jmp *0x24(%rbx)
e: 68 30 00 00 00 push $0x30
13: e9 80 ff ff ff jmp 0xffffffffffffff98
18: ff a3 f8 ff ff ff jmp *-0x8(%rbx)
1e: 66 90 xchg %ax,%ax
...
28: cd 80 int $0x80
2a:* c3 ret <-- trapping instruction
2b: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
32: 8d b6 00 00 00 00 lea 0x0(%rsi),%esi
38: 8b 1c 24 mov (%rsp),%ebx
3b: c3 ret
3c: 8d .byte 0x8d
3d: b4 26 mov $0x26,%ah
...
Code starting with the faulting instruction
===========================================
0: c3 ret
1: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
8: 8d b6 00 00 00 00 lea 0x0(%rsi),%esi
e: 8b 1c 24 mov (%rsp),%ebx
11: c3 ret
12: 8d .byte 0x8d
13: b4 26 mov $0x26,%ah
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20240903/202409031602.14479174-lkp@intel.com
On 9/3/24 14:15, kernel test robot wrote: > > Hello, > > kernel test robot noticed "BUG:sleeping_function_called_from_invalid_context_at_mm/memory.c" on: > > commit: c636ba74f021bfe8d72845f9e53ee2b8ea16f5f8 ("[PATCH 2/2] mm: Allocate THP on hugezeropage wp-fault") > url: https://github.com/intel-lab-lkp/linux/commits/Dev-Jain/mm-Abstract-THP-allocation/20240830-164300 > base: https://git.kernel.org/cgit/linux/kernel/git/akpm/mm.git mm-everything > patch link: https://lore.kernel.org/all/20240830084117.4079805-3-dev.jain@arm.com/ > patch subject: [PATCH 2/2] mm: Allocate THP on hugezeropage wp-fault > > in testcase: trinity > version: trinity-i386-abe9de86-1_20230429 > with following parameters: > > runtime: 600s > > > > compiler: gcc-12 > test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G > > (please refer to attached dmesg/kmsg for entire log/backtrace) > > > > 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 <oliver.sang@intel.com> > | Closes: https://lore.kernel.org/oe-lkp/202409031602.14479174-lkp@intel.com > > > [ 189.202955][T15284] BUG: sleeping function called from invalid context at mm/memory.c:6690 > [ 189.203611][T15284] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 15284, name: trinity-c6 I guess, since thp_fault_alloc() may sleep due to folio_zero_user(), I need to call it before do_huge_zero_wp_pmd_locked(). I will send a v2 since I also need to clean up the lock/unlock sites. > >
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index e25d9ebfdf89..375dba4fb130 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -9,6 +9,13 @@ #include <linux/kobject.h> vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf); +vm_fault_t thp_fault_alloc(gfp_t gfp, int order, struct vm_area_struct *vma, + unsigned long haddr, struct folio **foliop, + unsigned long addr); +void map_pmd_thp(struct folio *folio, struct vm_fault *vmf, + struct vm_area_struct *vma, unsigned long haddr, + pgtable_t pgtable) + __releases(vmf->ptl); int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e5b568e2bb34..0f8b2e224795 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -943,9 +943,9 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr, } EXPORT_SYMBOL_GPL(thp_get_unmapped_area); -static vm_fault_t thp_fault_alloc(gfp_t gfp, int order, struct vm_area_struct *vma, - unsigned long haddr, struct folio **foliop, - unsigned long addr) +vm_fault_t thp_fault_alloc(gfp_t gfp, int order, struct vm_area_struct *vma, + unsigned long haddr, struct folio **foliop, + unsigned long addr) { struct folio *folio = vma_alloc_folio(gfp, order, vma, haddr, true); @@ -984,22 +984,30 @@ static void __thp_fault_success_stats(struct vm_area_struct *vma, int order) count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); } -static void map_pmd_thp(struct folio *folio, struct vm_fault *vmf, - struct vm_area_struct *vma, unsigned long haddr, - pgtable_t pgtable) +void map_pmd_thp(struct folio *folio, struct vm_fault *vmf, + struct vm_area_struct *vma, unsigned long haddr, + pgtable_t pgtable) __releases(vmf->ptl) { - pmd_t entry; + pmd_t entry, old_pmd; + bool is_pmd_none = pmd_none(*vmf->pmd); entry = mk_huge_pmd(&folio->page, vma->vm_page_prot); entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); folio_add_new_anon_rmap(folio, vma, haddr, RMAP_EXCLUSIVE); folio_add_lru_vma(folio, vma); - pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); + if (!is_pmd_none) { + old_pmd = pmdp_huge_clear_flush(vma, haddr, vmf->pmd); + if (pmd_uffd_wp(old_pmd)) + entry = pmd_mkuffd_wp(entry); + } + if (pgtable) + pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR); - mm_inc_nr_ptes(vma->vm_mm); + if (is_pmd_none) + mm_inc_nr_ptes(vma->vm_mm); spin_unlock(vmf->ptl); __thp_fault_success_stats(vma, HPAGE_PMD_ORDER); } @@ -1577,6 +1585,47 @@ void huge_pmd_set_accessed(struct vm_fault *vmf) spin_unlock(vmf->ptl); } +static vm_fault_t do_huge_zero_wp_pmd_locked(struct vm_fault *vmf, + unsigned long haddr) +{ + struct vm_area_struct *vma = vmf->vma; + gfp_t gfp = vma_thp_gfp_mask(vma); + struct folio *folio = NULL; + vm_fault_t ret; + + ret = thp_fault_alloc(gfp, HPAGE_PMD_ORDER, vma, haddr, &folio, + vmf->address); + if (ret) + goto unlock; + ret = check_stable_address_space(vma->vm_mm); + if (ret) + goto unlock; + map_pmd_thp(folio, vmf, vma, haddr, NULL); + return 0; + +unlock: + spin_unlock(vmf->ptl); + return ret; +} + +static vm_fault_t do_huge_zero_wp_pmd(struct vm_fault *vmf, unsigned long haddr) +{ + struct vm_area_struct *vma = vmf->vma; + struct mmu_notifier_range range; + vm_fault_t ret = 0; + + mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, haddr, + haddr + HPAGE_PMD_SIZE); + mmu_notifier_invalidate_range_start(&range); + vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); + if (likely(pmd_same(pmdp_get(vmf->pmd), vmf->orig_pmd))) + ret = do_huge_zero_wp_pmd_locked(vmf, haddr); + else + spin_unlock(vmf->ptl); + mmu_notifier_invalidate_range_end(&range); + return ret; +} + vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) { const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE; @@ -1589,8 +1638,15 @@ vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) vmf->ptl = pmd_lockptr(vma->vm_mm, vmf->pmd); VM_BUG_ON_VMA(!vma->anon_vma, vma); - if (is_huge_zero_pmd(orig_pmd)) + if (is_huge_zero_pmd(orig_pmd)) { + vm_fault_t ret = do_huge_zero_wp_pmd(vmf, haddr); + + if (!(ret & VM_FAULT_FALLBACK)) + return ret; + + /* Fallback to splitting PMD if THP cannot be allocated */ goto fallback; + } spin_lock(vmf->ptl); diff --git a/mm/memory.c b/mm/memory.c index 3c01d68065be..c081a25f5173 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5409,9 +5409,10 @@ static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf) if (vma_is_anonymous(vma)) { if (likely(!unshare) && userfaultfd_huge_pmd_wp(vma, vmf->orig_pmd)) { - if (userfaultfd_wp_async(vmf->vma)) + if (!userfaultfd_wp_async(vmf->vma)) + return handle_userfault(vmf, VM_UFFD_WP); + if (!is_huge_zero_pmd(vmf->orig_pmd)) goto split; - return handle_userfault(vmf, VM_UFFD_WP); } return do_huge_pmd_wp_page(vmf); }
Introduce do_huge_zero_wp_pmd() to handle wp-fault on a hugezeropage and replace it with a PMD-mapped THP. Change the helpers introduced in the previous patch to flush TLB entry corresponding to the hugezeropage, and preserve PMD uffd-wp marker. In case of failure, fallback to splitting the PMD. Signed-off-by: Dev Jain <dev.jain@arm.com> --- include/linux/huge_mm.h | 7 ++++ mm/huge_memory.c | 76 +++++++++++++++++++++++++++++++++++------ mm/memory.c | 5 +-- 3 files changed, 76 insertions(+), 12 deletions(-)