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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 5A5D840079 X-Stat-Signature: kxhi3ndd7pj6dcgxf9ufi8d4ykdcgi9s X-Rspam-User: X-HE-Tag: 1720530233-974069 X-HE-Meta: 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 pvYY/9Y2 zCIkGagkxbUpH0tJ+Th3MQw4MEQKEUA/4B8n1wpiHkz4Od/Moh9kXGxFiKeFSxuu1Uh1oHxv2oD81345BzjYQ2SgPMzn029KJMACsz+YDC+6BUUZOSf/N83wtHinIGJ2SAguNLmH/IUyhTScZYXKiDjslUQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 03/05/2024 15:01, Joey Gouly wrote: > [...] > > +static bool fault_from_pkey(unsigned long esr, struct vm_area_struct *vma, > + unsigned int mm_flags) > +{ > + unsigned long iss2 = ESR_ELx_ISS2(esr); > + > + if (!arch_pkeys_enabled()) > + return false; > + > + if (iss2 & ESR_ELx_Overlay) > + return true; > + > + return !arch_vma_access_permitted(vma, > + mm_flags & FAULT_FLAG_WRITE, > + mm_flags & FAULT_FLAG_INSTRUCTION, > + mm_flags & FAULT_FLAG_REMOTE); This function is only called from do_page_fault(), so the access cannot be remote. The equivalent x86 function (access_error()) always sets foreign to false. > +} > + > static vm_fault_t __do_page_fault(struct mm_struct *mm, > struct vm_area_struct *vma, unsigned long addr, > unsigned int mm_flags, unsigned long vm_flags, > @@ -529,6 +547,8 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, > unsigned int mm_flags = FAULT_FLAG_DEFAULT; > unsigned long addr = untagged_addr(far); > struct vm_area_struct *vma; > + bool pkey_fault = false; > + int pkey = -1; > > if (kprobe_page_fault(regs, esr)) > return 0; > @@ -590,6 +610,12 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, > vma_end_read(vma); > goto lock_mmap; > } > + > + if (fault_from_pkey(esr, vma, mm_flags)) { > + vma_end_read(vma); > + goto lock_mmap; > + } > + > fault = handle_mm_fault(vma, addr, mm_flags | FAULT_FLAG_VMA_LOCK, regs); > if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))) > vma_end_read(vma); > @@ -617,6 +643,11 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, > goto done; > } > > + if (fault_from_pkey(esr, vma, mm_flags)) { > + pkey_fault = true; > + pkey = vma_pkey(vma); > + } > + > fault = __do_page_fault(mm, vma, addr, mm_flags, vm_flags, regs); We don't actually need to call __do_page_fault()/handle_mm_fault() if the fault was caused by POE. It still works since it checks arch_vma_access_permitted() early, but we might as well skip it altogether (like on x86). On 6.10-rcX, we could handle it like a missing vm_flags (goto bad_area). Kevin