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Message-ID: <20230821123056.2109942-4-wangkefeng.wang@huawei.com>
Date: Mon, 21 Aug 2023 20:30:49 +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>,
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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 03/10] x86: 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/x86/mm/fault.c | 55 +++++++++++++++++++--------------------------
1 file changed, 23 insertions(+), 32 deletions(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index ab778eac1952..3edc9edc0b28 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1227,6 +1227,13 @@ do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code,
}
NOKPROBE_SYMBOL(do_kern_addr_fault);
+#ifdef CONFIG_PER_VMA_LOCK
+bool arch_vma_access_error(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ return access_error(vmf->fault_code, vma);
+}
+#endif
+
/*
* Handle faults in the user portion of the address space. Nothing in here
* should check X86_PF_USER without a specific justification: for almost
@@ -1241,13 +1248,13 @@ void do_user_addr_fault(struct pt_regs *regs,
unsigned long address)
{
struct vm_area_struct *vma;
- struct task_struct *tsk;
- struct mm_struct *mm;
+ struct mm_struct *mm = current->mm;
vm_fault_t fault;
- unsigned int flags = FAULT_FLAG_DEFAULT;
-
- tsk = current;
- mm = tsk->mm;
+ struct vm_fault vmf = {
+ .real_address = address,
+ .fault_code = error_code,
+ .flags = FAULT_FLAG_DEFAULT
+ };
if (unlikely((error_code & (X86_PF_USER | X86_PF_INSTR)) == X86_PF_INSTR)) {
/*
@@ -1311,7 +1318,7 @@ void do_user_addr_fault(struct pt_regs *regs,
*/
if (user_mode(regs)) {
local_irq_enable();
- flags |= FAULT_FLAG_USER;
+ vmf.flags |= FAULT_FLAG_USER;
} else {
if (regs->flags & X86_EFLAGS_IF)
local_irq_enable();
@@ -1326,11 +1333,11 @@ void do_user_addr_fault(struct pt_regs *regs,
* maybe_mkwrite() can create a proper shadow stack PTE.
*/
if (error_code & X86_PF_SHSTK)
- flags |= FAULT_FLAG_WRITE;
+ vmf.flags |= FAULT_FLAG_WRITE;
if (error_code & X86_PF_WRITE)
- flags |= FAULT_FLAG_WRITE;
+ vmf.flags |= FAULT_FLAG_WRITE;
if (error_code & X86_PF_INSTR)
- flags |= FAULT_FLAG_INSTRUCTION;
+ vmf.flags |= FAULT_FLAG_INSTRUCTION;
#ifdef CONFIG_X86_64
/*
@@ -1350,26 +1357,11 @@ void do_user_addr_fault(struct pt_regs *regs,
}
#endif
- if (!(flags & FAULT_FLAG_USER))
- goto lock_mmap;
-
- vma = lock_vma_under_rcu(mm, address);
- if (!vma)
- goto lock_mmap;
-
- if (unlikely(access_error(error_code, vma))) {
- 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);
+ fault = try_vma_locked_page_fault(&vmf);
+ if (fault == VM_FAULT_NONE)
+ goto retry;
+ if (!(fault & VM_FAULT_RETRY))
goto done;
- }
- count_vm_vma_lock_event(VMA_LOCK_RETRY);
/* Quick path to respond to signals */
if (fault_signal_pending(fault, regs)) {
@@ -1379,7 +1371,6 @@ void do_user_addr_fault(struct pt_regs *regs,
ARCH_DEFAULT_PKEY);
return;
}
-lock_mmap:
retry:
vma = lock_mm_and_find_vma(mm, address, regs);
@@ -1410,7 +1401,7 @@ void do_user_addr_fault(struct pt_regs *regs,
* userland). The return to userland is identified whenever
* FAULT_FLAG_USER|FAULT_FLAG_KILLABLE are both set in flags.
*/
- fault = handle_mm_fault(vma, address, flags, regs);
+ fault = handle_mm_fault(vma, address, vmf.flags, regs);
if (fault_signal_pending(fault, regs)) {
/*
@@ -1434,7 +1425,7 @@ void do_user_addr_fault(struct pt_regs *regs,
* that we made any progress. Handle this case first.
*/
if (unlikely(fault & VM_FAULT_RETRY)) {
- flags |= FAULT_FLAG_TRIED;
+ vmf.flags |= FAULT_FLAG_TRIED;
goto retry;
}
--
2.27.0
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