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Message-ID: <20230821123056.2109942-6-wangkefeng.wang@huawei.com>
Date: Mon, 21 Aug 2023 20:30:51 +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>,
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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 05/10] powerpc: 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/powerpc/mm/fault.c | 66 ++++++++++++++++++++---------------------
1 file changed, 32 insertions(+), 34 deletions(-)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index b1723094d464..52f9546e020e 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -391,6 +391,22 @@ static int page_fault_is_bad(unsigned long err)
#define page_fault_is_bad(__err) ((__err) & DSISR_BAD_FAULT_32S)
#endif
+#ifdef CONFIG_PER_VMA_LOCK
+bool arch_vma_access_error(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ int is_exec = TRAP(vmf->regs) == INTERRUPT_INST_STORAGE;
+ int is_write = page_fault_is_write(vmf->fault_code);
+
+ if (unlikely(access_pkey_error(is_write, is_exec,
+ (vmf->fault_code & DSISR_KEYFAULT), vma)))
+ return true;
+
+ if (unlikely(access_error(is_write, is_exec, vma)))
+ return true;
+ return false;
+}
+#endif
+
/*
* For 600- and 800-family processors, the error_code parameter is DSISR
* for a data fault, SRR1 for an instruction fault.
@@ -407,12 +423,18 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
{
struct vm_area_struct * vma;
struct mm_struct *mm = current->mm;
- unsigned int flags = FAULT_FLAG_DEFAULT;
int is_exec = TRAP(regs) == INTERRUPT_INST_STORAGE;
int is_user = user_mode(regs);
int is_write = page_fault_is_write(error_code);
vm_fault_t fault, major = 0;
bool kprobe_fault = kprobe_page_fault(regs, 11);
+ struct vm_fault vmf = {
+ .real_address = address,
+ .fault_code = error_code,
+ .regs = regs,
+ .flags = FAULT_FLAG_DEFAULT,
+ };
+
if (unlikely(debugger_fault_handler(regs) || kprobe_fault))
return 0;
@@ -463,45 +485,21 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
* mmap_lock held
*/
if (is_user)
- flags |= FAULT_FLAG_USER;
+ vmf.flags |= FAULT_FLAG_USER;
if (is_write)
- flags |= FAULT_FLAG_WRITE;
+ vmf.flags |= FAULT_FLAG_WRITE;
if (is_exec)
- flags |= FAULT_FLAG_INSTRUCTION;
+ vmf.flags |= FAULT_FLAG_INSTRUCTION;
- if (!(flags & FAULT_FLAG_USER))
- goto lock_mmap;
-
- vma = lock_vma_under_rcu(mm, address);
- if (!vma)
- goto lock_mmap;
-
- if (unlikely(access_pkey_error(is_write, is_exec,
- (error_code & DSISR_KEYFAULT), vma))) {
- vma_end_read(vma);
- goto lock_mmap;
- }
-
- if (unlikely(access_error(is_write, is_exec, 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);
if (fault_signal_pending(fault, regs))
return user_mode(regs) ? 0 : SIGBUS;
-lock_mmap:
-
/* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the
* kernel and should generate an OOPS. Unfortunately, in the case of an
@@ -528,7 +526,7 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
* 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);
major |= fault & VM_FAULT_MAJOR;
@@ -544,7 +542,7 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
* case.
*/
if (unlikely(fault & VM_FAULT_RETRY)) {
- flags |= FAULT_FLAG_TRIED;
+ vmf.flags |= FAULT_FLAG_TRIED;
goto retry;
}
--
2.27.0
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