~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/arc/mm/fault.c

Version: ~ [ linux-5.16-rc3 ] ~ [ linux-5.15.5 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.82 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.162 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.218 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.256 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.291 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.293 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /* Page Fault Handling for ARC (TLB Miss / ProtV)
  3  *
  4  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  5  */
  6 
  7 #include <linux/signal.h>
  8 #include <linux/interrupt.h>
  9 #include <linux/sched/signal.h>
 10 #include <linux/errno.h>
 11 #include <linux/ptrace.h>
 12 #include <linux/uaccess.h>
 13 #include <linux/kdebug.h>
 14 #include <linux/perf_event.h>
 15 #include <linux/mm_types.h>
 16 #include <asm/mmu.h>
 17 
 18 /*
 19  * kernel virtual address is required to implement vmalloc/pkmap/fixmap
 20  * Refer to asm/processor.h for System Memory Map
 21  *
 22  * It simply copies the PMD entry (pointer to 2nd level page table or hugepage)
 23  * from swapper pgdir to task pgdir. The 2nd level table/page is thus shared
 24  */
 25 noinline static int handle_kernel_vaddr_fault(unsigned long address)
 26 {
 27         /*
 28          * Synchronize this task's top level page-table
 29          * with the 'reference' page table.
 30          */
 31         pgd_t *pgd, *pgd_k;
 32         p4d_t *p4d, *p4d_k;
 33         pud_t *pud, *pud_k;
 34         pmd_t *pmd, *pmd_k;
 35 
 36         pgd = pgd_offset_fast(current->active_mm, address);
 37         pgd_k = pgd_offset_k(address);
 38 
 39         if (!pgd_present(*pgd_k))
 40                 goto bad_area;
 41 
 42         p4d = p4d_offset(pgd, address);
 43         p4d_k = p4d_offset(pgd_k, address);
 44         if (!p4d_present(*p4d_k))
 45                 goto bad_area;
 46 
 47         pud = pud_offset(p4d, address);
 48         pud_k = pud_offset(p4d_k, address);
 49         if (!pud_present(*pud_k))
 50                 goto bad_area;
 51 
 52         pmd = pmd_offset(pud, address);
 53         pmd_k = pmd_offset(pud_k, address);
 54         if (!pmd_present(*pmd_k))
 55                 goto bad_area;
 56 
 57         set_pmd(pmd, *pmd_k);
 58 
 59         /* XXX: create the TLB entry here */
 60         return 0;
 61 
 62 bad_area:
 63         return 1;
 64 }
 65 
 66 void do_page_fault(unsigned long address, struct pt_regs *regs)
 67 {
 68         struct vm_area_struct *vma = NULL;
 69         struct task_struct *tsk = current;
 70         struct mm_struct *mm = tsk->mm;
 71         int sig, si_code = SEGV_MAPERR;
 72         unsigned int write = 0, exec = 0, mask;
 73         vm_fault_t fault = VM_FAULT_SIGSEGV;    /* handle_mm_fault() output */
 74         unsigned int flags;                     /* handle_mm_fault() input */
 75 
 76         /*
 77          * NOTE! We MUST NOT take any locks for this case. We may
 78          * be in an interrupt or a critical region, and should
 79          * only copy the information from the master page table,
 80          * nothing more.
 81          */
 82         if (address >= VMALLOC_START && !user_mode(regs)) {
 83                 if (unlikely(handle_kernel_vaddr_fault(address)))
 84                         goto no_context;
 85                 else
 86                         return;
 87         }
 88 
 89         /*
 90          * If we're in an interrupt or have no user
 91          * context, we must not take the fault..
 92          */
 93         if (faulthandler_disabled() || !mm)
 94                 goto no_context;
 95 
 96         if (regs->ecr_cause & ECR_C_PROTV_STORE)        /* ST/EX */
 97                 write = 1;
 98         else if ((regs->ecr_vec == ECR_V_PROTV) &&
 99                  (regs->ecr_cause == ECR_C_PROTV_INST_FETCH))
100                 exec = 1;
101 
102         flags = FAULT_FLAG_DEFAULT;
103         if (user_mode(regs))
104                 flags |= FAULT_FLAG_USER;
105         if (write)
106                 flags |= FAULT_FLAG_WRITE;
107 
108         perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
109 retry:
110         mmap_read_lock(mm);
111 
112         vma = find_vma(mm, address);
113         if (!vma)
114                 goto bad_area;
115         if (unlikely(address < vma->vm_start)) {
116                 if (!(vma->vm_flags & VM_GROWSDOWN) || expand_stack(vma, address))
117                         goto bad_area;
118         }
119 
120         /*
121          * vm_area is good, now check permissions for this memory access
122          */
123         mask = VM_READ;
124         if (write)
125                 mask = VM_WRITE;
126         if (exec)
127                 mask = VM_EXEC;
128 
129         if (!(vma->vm_flags & mask)) {
130                 si_code = SEGV_ACCERR;
131                 goto bad_area;
132         }
133 
134         fault = handle_mm_fault(vma, address, flags, regs);
135 
136         /* Quick path to respond to signals */
137         if (fault_signal_pending(fault, regs)) {
138                 if (!user_mode(regs))
139                         goto no_context;
140                 return;
141         }
142 
143         /*
144          * Fault retry nuances, mmap_lock already relinquished by core mm
145          */
146         if (unlikely((fault & VM_FAULT_RETRY) &&
147                      (flags & FAULT_FLAG_ALLOW_RETRY))) {
148                 flags |= FAULT_FLAG_TRIED;
149                 goto retry;
150         }
151 
152 bad_area:
153         mmap_read_unlock(mm);
154 
155         /*
156          * Major/minor page fault accounting
157          * (in case of retry we only land here once)
158          */
159         if (likely(!(fault & VM_FAULT_ERROR)))
160                 /* Normal return path: fault Handled Gracefully */
161                 return;
162 
163         if (!user_mode(regs))
164                 goto no_context;
165 
166         if (fault & VM_FAULT_OOM) {
167                 pagefault_out_of_memory();
168                 return;
169         }
170 
171         if (fault & VM_FAULT_SIGBUS) {
172                 sig = SIGBUS;
173                 si_code = BUS_ADRERR;
174         }
175         else {
176                 sig = SIGSEGV;
177         }
178 
179         tsk->thread.fault_address = address;
180         force_sig_fault(sig, si_code, (void __user *)address);
181         return;
182 
183 no_context:
184         if (fixup_exception(regs))
185                 return;
186 
187         die("Oops", regs, address);
188 }
189 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp