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Message-ID: <20230821123056.2109942-5-wangkefeng.wang@huawei.com>
Date: Mon, 21 Aug 2023 20:30:50 +0800
From: Kefeng Wang <wangkefeng.wang@...wei.com>
To: Andrew Morton <akpm@...ux-foundation.org>, <linux-mm@...ck.org>
CC: <surenb@...gle.com>, <willy@...radead.org>,
Russell King <linux@...linux.org.uk>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>,
Huacai Chen <chenhuacai@...nel.org>,
WANG Xuerui <kernel@...0n.name>,
Michael Ellerman <mpe@...erman.id.au>,
Nicholas Piggin <npiggin@...il.com>,
Christophe Leroy <christophe.leroy@...roup.eu>,
Paul Walmsley <paul.walmsley@...ive.com>,
Palmer Dabbelt <palmer@...belt.com>,
Albert Ou <aou@...s.berkeley.edu>,
Alexander Gordeev <agordeev@...ux.ibm.com>,
Gerald Schaefer <gerald.schaefer@...ux.ibm.com>,
Heiko Carstens <hca@...ux.ibm.com>,
Vasily Gorbik <gor@...ux.ibm.com>,
Christian Borntraeger <borntraeger@...ux.ibm.com>,
Sven Schnelle <svens@...ux.ibm.com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Andy Lutomirski <luto@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
<x86@...nel.org>, "H . Peter Anvin" <hpa@...or.com>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <loongarch@...ts.linux.dev>,
<linuxppc-dev@...ts.ozlabs.org>, <linux-riscv@...ts.infradead.org>,
<linux-s390@...r.kernel.org>,
Kefeng Wang <wangkefeng.wang@...wei.com>
Subject: [PATCH rfc v2 04/10] s390: mm: use try_vma_locked_page_fault()
Use new try_vma_locked_page_fault() helper to simplify code.
No functional change intended.
Signed-off-by: Kefeng Wang <wangkefeng.wang@...wei.com>
---
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;
}
--
2.27.0
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