[PATCH rfc v2 05/10] powerpc: mm: use try_vma_locked_page_fault()
From: Kefeng Wang <hidden>
Date: 2023-08-21 12:31:27
Also in:
linux-arm-kernel, linux-mm, linux-riscv, linux-s390, lkml, loongarch
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Use new try_vma_locked_page_fault() helper to simplify code. No functional change intended. Signed-off-by: Kefeng Wang <redacted> --- 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