+// SPDX-License-Identifier: GPL-2.0-only
/* Page Fault Handling for ARC (TLB Miss / ProtV)
*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*/
#include <linux/signal.h>
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
int si_code = SEGV_MAPERR;
- int ret;
+ unsigned int write = 0, exec = 0, mask;
vm_fault_t fault;
- int write = regs->ecr_cause & ECR_C_PROTV_STORE; /* ST/EX */
- unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+ unsigned int flags;
/*
- * We fault-in kernel-space virtual memory on-demand. The
- * 'reference' page table is init_mm.pgd.
- *
* NOTE! We MUST NOT take any locks for this case. We may
* be in an interrupt or a critical region, and should
* only copy the information from the master page table,
* nothing more.
*/
if (address >= VMALLOC_START && !user_mode(regs)) {
- ret = handle_kernel_vaddr_fault(address);
- if (unlikely(ret))
+ if (unlikely(handle_kernel_vaddr_fault(address)))
goto no_context;
else
return;
if (faulthandler_disabled() || !mm)
goto no_context;
+ if (regs->ecr_cause & ECR_C_PROTV_STORE) /* ST/EX */
+ write = 1;
+ else if ((regs->ecr_vec == ECR_V_PROTV) &&
+ (regs->ecr_cause == ECR_C_PROTV_INST_FETCH))
+ exec = 1;
+
+ flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
if (user_mode(regs))
flags |= FAULT_FLAG_USER;
+ if (write)
+ flags |= FAULT_FLAG_WRITE;
+
retry:
down_read(&mm->mmap_sem);
+
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
- if (vma->vm_start <= address)
- goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
- if (expand_stack(vma, address))
- goto bad_area;
+ if (unlikely(address < vma->vm_start)) {
+ if (!(vma->vm_flags & VM_GROWSDOWN) || expand_stack(vma, address))
+ goto bad_area;
+ }
/*
- * Ok, we have a good vm_area for this memory access, so
- * we can handle it..
+ * vm_area is good, now check permissions for this memory access
*/
-good_area:
- si_code = SEGV_ACCERR;
-
- /* Handle protection violation, execute on heap or stack */
-
- if ((regs->ecr_vec == ECR_V_PROTV) &&
- (regs->ecr_cause == ECR_C_PROTV_INST_FETCH))
+ mask = VM_READ;
+ if (write)
+ mask = VM_WRITE;
+ if (exec)
+ mask = VM_EXEC;
+
+ if (!(vma->vm_flags & mask)) {
+ si_code = SEGV_ACCERR;
goto bad_area;
-
- if (write) {
- if (!(vma->vm_flags & VM_WRITE))
- goto bad_area;
- flags |= FAULT_FLAG_WRITE;
- } else {
- if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
- goto bad_area;
}
/*