From 4e2e391ff7242998c8dcb871bac429b3e34454c4 Mon Sep 17 00:00:00 2001 From: Michel Lespinasse Date: Mon, 24 Jan 2022 17:43:54 -0800 Subject: [PATCH] BACKPORT: FROMLIST: mm: add do_handle_mm_fault() Add a new do_handle_mm_fault function, which extends the existing handle_mm_fault() API by adding an mmap sequence count, to be used in the FAULT_FLAG_SPECULATIVE case. In the initial implementation, FAULT_FLAG_SPECULATIVE always fails (by returning VM_FAULT_RETRY). The existing handle_mm_fault() API is kept as a wrapper around do_handle_mm_fault() so that we do not have to immediately update every handle_mm_fault() call site. Signed-off-by: Michel Lespinasse Conflicts: mm/memory.c 1. Trivial merge conflict due to folios. Link: https://lore.kernel.org/all/20220128131006.67712-10-michel@lespinasse.org/ Bug: 161210518 Signed-off-by: Suren Baghdasaryan Change-Id: Ic07b6d84af3e5d1fcc856e0968f1a6dd1544fa88 --- include/linux/mm.h | 12 +++++++++--- mm/memory.c | 10 +++++++--- 2 files changed, 16 insertions(+), 6 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 980d10dc1499..cd7a7a50dd62 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1776,9 +1776,15 @@ int generic_error_remove_page(struct address_space *mapping, struct page *page); int invalidate_inode_page(struct page *page); #ifdef CONFIG_MMU -extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma, - unsigned long address, unsigned int flags, - struct pt_regs *regs); +extern vm_fault_t do_handle_mm_fault(struct vm_area_struct *vma, + unsigned long address, unsigned int flags, + unsigned long seq, struct pt_regs *regs); +static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma, + unsigned long address, unsigned int flags, + struct pt_regs *regs) +{ + return do_handle_mm_fault(vma, address, flags, 0, regs); +} extern int fixup_user_fault(struct mm_struct *mm, unsigned long address, unsigned int fault_flags, bool *unlocked); diff --git a/mm/memory.c b/mm/memory.c index 0ed79b4aa49c..ca43ee0d8a09 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4763,11 +4763,15 @@ static inline void mm_account_fault(struct pt_regs *regs, * The mmap_lock may have been released depending on flags and our * return value. See filemap_fault() and __lock_page_or_retry(). */ -vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, - unsigned int flags, struct pt_regs *regs) +vm_fault_t do_handle_mm_fault(struct vm_area_struct *vma, + unsigned long address, unsigned int flags, + unsigned long seq, struct pt_regs *regs) { vm_fault_t ret; + if (flags & FAULT_FLAG_SPECULATIVE) + return VM_FAULT_RETRY; + __set_current_state(TASK_RUNNING); count_vm_event(PGFAULT); @@ -4809,7 +4813,7 @@ vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, return ret; } -EXPORT_SYMBOL_GPL(handle_mm_fault); +EXPORT_SYMBOL_GPL(do_handle_mm_fault); #ifndef __PAGETABLE_P4D_FOLDED /*