Re: [PATCH v4 15/29] arm64: handle PKEY/POE faults
flat view
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2024-06-21 16:57:40
Also in:
kvmarm, linux-arm-kernel, linux-fsdevel, linux-mm
On Fri, May 03, 2024 at 02:01:33PM +0100, Joey Gouly wrote:
quoted hunk ↗ jump to hunk
@@ -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); + }
I was wondering if we actually need to test this again. We know the fault was from a pkey already above but I guess it matches what we do with the vma->vm_flags check in case it races with some mprotect() call.
+ fault = __do_page_fault(mm, vma, addr, mm_flags, vm_flags, regs);
You'll need to rebase this on 6.10-rcX since this function disappeared. Otherwise the patch looks fine. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>