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Peter Anvin" , , , , , , , Kefeng Wang Subject: [PATCH rfc v2 04/10] s390: mm: use try_vma_locked_page_fault() Date: Mon, 21 Aug 2023 20:30:50 +0800 Message-ID: <20230821123056.2109942-5-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20230821123056.2109942-1-wangkefeng.wang@huawei.com> References: <20230821123056.2109942-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm100001.china.huawei.com (7.185.36.93) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230821_053121_874430_AF0E4475 X-CRM114-Status: GOOD ( 15.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Use new try_vma_locked_page_fault() helper to simplify code. No functional change intended. Signed-off-by: Kefeng Wang --- arch/s390/mm/fault.c | 66 ++++++++++++++++++-------------------------- 1 file changed, 27 insertions(+), 39 deletions(-) diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 099c4824dd8a..fbbdebde6ea7 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -357,16 +357,18 @@ static noinline void do_fault_error(struct pt_regs *regs, vm_fault_t fault) static inline vm_fault_t do_exception(struct pt_regs *regs, int access) { struct gmap *gmap; - struct task_struct *tsk; - struct mm_struct *mm; struct vm_area_struct *vma; enum fault_type type; - unsigned long address; - unsigned int flags; + struct mm_struct *mm = current->mm; + unsigned long address = get_fault_address(regs); vm_fault_t fault; bool is_write; + struct vm_fault vmf = { + .real_address = address, + .flags = FAULT_FLAG_DEFAULT, + .vm_flags = access, + }; - tsk = current; /* * The instruction that caused the program check has * been nullified. Don't signal single step via SIGTRAP. @@ -376,8 +378,6 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) if (kprobe_page_fault(regs, 14)) return 0; - mm = tsk->mm; - address = get_fault_address(regs); is_write = fault_is_write(regs); /* @@ -398,45 +398,33 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) } perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); - flags = FAULT_FLAG_DEFAULT; if (user_mode(regs)) - flags |= FAULT_FLAG_USER; + vmf.flags |= FAULT_FLAG_USER; if (is_write) - access = VM_WRITE; - if (access == VM_WRITE) - flags |= FAULT_FLAG_WRITE; - if (!(flags & FAULT_FLAG_USER)) - goto lock_mmap; - vma = lock_vma_under_rcu(mm, address); - if (!vma) - goto lock_mmap; - if (!(vma->vm_flags & access)) { - vma_end_read(vma); - goto lock_mmap; - } - fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs); - if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))) - vma_end_read(vma); - if (!(fault & VM_FAULT_RETRY)) { - count_vm_vma_lock_event(VMA_LOCK_SUCCESS); - if (likely(!(fault & VM_FAULT_ERROR))) - fault = 0; + vmf.vm_flags = VM_WRITE; + if (vmf.vm_flags == VM_WRITE) + vmf.flags |= FAULT_FLAG_WRITE; + + fault = try_vma_locked_page_fault(&vmf); + if (fault == VM_FAULT_NONE) + goto lock_mm; + if (!(fault & VM_FAULT_RETRY)) goto out; - } - count_vm_vma_lock_event(VMA_LOCK_RETRY); + /* Quick path to respond to signals */ if (fault_signal_pending(fault, regs)) { fault = VM_FAULT_SIGNAL; goto out; } -lock_mmap: + +lock_mm: mmap_read_lock(mm); gmap = NULL; if (IS_ENABLED(CONFIG_PGSTE) && type == GMAP_FAULT) { gmap = (struct gmap *) S390_lowcore.gmap; current->thread.gmap_addr = address; - current->thread.gmap_write_flag = !!(flags & FAULT_FLAG_WRITE); + current->thread.gmap_write_flag = !!(vmf.flags & FAULT_FLAG_WRITE); current->thread.gmap_int_code = regs->int_code & 0xffff; address = __gmap_translate(gmap, address); if (address == -EFAULT) { @@ -444,7 +432,7 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) goto out_up; } if (gmap->pfault_enabled) - flags |= FAULT_FLAG_RETRY_NOWAIT; + vmf.flags |= FAULT_FLAG_RETRY_NOWAIT; } retry: @@ -466,7 +454,7 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) * we can handle it.. */ fault = VM_FAULT_BADACCESS; - if (unlikely(!(vma->vm_flags & access))) + if (unlikely(!(vma->vm_flags & vmf.vm_flags))) goto out_up; /* @@ -474,10 +462,10 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) * make sure we exit gracefully rather than endlessly redo * the fault. */ - fault = handle_mm_fault(vma, address, flags, regs); + fault = handle_mm_fault(vma, address, vmf.flags, regs); if (fault_signal_pending(fault, regs)) { fault = VM_FAULT_SIGNAL; - if (flags & FAULT_FLAG_RETRY_NOWAIT) + if (vmf.flags & FAULT_FLAG_RETRY_NOWAIT) goto out_up; goto out; } @@ -497,7 +485,7 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) if (fault & VM_FAULT_RETRY) { if (IS_ENABLED(CONFIG_PGSTE) && gmap && - (flags & FAULT_FLAG_RETRY_NOWAIT)) { + (vmf.flags & FAULT_FLAG_RETRY_NOWAIT)) { /* * FAULT_FLAG_RETRY_NOWAIT has been set, mmap_lock has * not been released @@ -506,8 +494,8 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) fault = VM_FAULT_PFAULT; goto out_up; } - flags &= ~FAULT_FLAG_RETRY_NOWAIT; - flags |= FAULT_FLAG_TRIED; + vmf.flags &= ~FAULT_FLAG_RETRY_NOWAIT; + vmf.flags |= FAULT_FLAG_TRIED; mmap_read_lock(mm); goto retry; }