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

TOMOYO Linux Cross Reference
Linux/arch/hexagon/mm/vm_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 /*
  3  * Memory fault handling for Hexagon
  4  *
  5  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
  6  */
  7 
  8 /*
  9  * Page fault handling for the Hexagon Virtual Machine.
 10  * Can also be called by a native port emulating the HVM
 11  * execptions.
 12  */
 13 
 14 #include <asm/traps.h>
 15 #include <linux/uaccess.h>
 16 #include <linux/mm.h>
 17 #include <linux/sched/signal.h>
 18 #include <linux/signal.h>
 19 #include <linux/extable.h>
 20 #include <linux/hardirq.h>
 21 #include <linux/perf_event.h>
 22 
 23 /*
 24  * Decode of hardware exception sends us to one of several
 25  * entry points.  At each, we generate canonical arguments
 26  * for handling by the abstract memory management code.
 27  */
 28 #define FLT_IFETCH     -1
 29 #define FLT_LOAD        0
 30 #define FLT_STORE       1
 31 
 32 
 33 /*
 34  * Canonical page fault handler
 35  */
 36 void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 37 {
 38         struct vm_area_struct *vma;
 39         struct mm_struct *mm = current->mm;
 40         int si_signo;
 41         int si_code = SEGV_MAPERR;
 42         vm_fault_t fault;
 43         const struct exception_table_entry *fixup;
 44         unsigned int flags = FAULT_FLAG_DEFAULT;
 45 
 46         /*
 47          * If we're in an interrupt or have no user context,
 48          * then must not take the fault.
 49          */
 50         if (unlikely(in_interrupt() || !mm))
 51                 goto no_context;
 52 
 53         local_irq_enable();
 54 
 55         if (user_mode(regs))
 56                 flags |= FAULT_FLAG_USER;
 57 
 58         perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 59 retry:
 60         mmap_read_lock(mm);
 61         vma = find_vma(mm, address);
 62         if (!vma)
 63                 goto bad_area;
 64 
 65         if (vma->vm_start <= address)
 66                 goto good_area;
 67 
 68         if (!(vma->vm_flags & VM_GROWSDOWN))
 69                 goto bad_area;
 70 
 71         if (expand_stack(vma, address))
 72                 goto bad_area;
 73 
 74 good_area:
 75         /* Address space is OK.  Now check access rights. */
 76         si_code = SEGV_ACCERR;
 77 
 78         switch (cause) {
 79         case FLT_IFETCH:
 80                 if (!(vma->vm_flags & VM_EXEC))
 81                         goto bad_area;
 82                 break;
 83         case FLT_LOAD:
 84                 if (!(vma->vm_flags & VM_READ))
 85                         goto bad_area;
 86                 break;
 87         case FLT_STORE:
 88                 if (!(vma->vm_flags & VM_WRITE))
 89                         goto bad_area;
 90                 flags |= FAULT_FLAG_WRITE;
 91                 break;
 92         }
 93 
 94         fault = handle_mm_fault(vma, address, flags, regs);
 95 
 96         if (fault_signal_pending(fault, regs))
 97                 return;
 98 
 99         /* The most common case -- we are done. */
100         if (likely(!(fault & VM_FAULT_ERROR))) {
101                 if (flags & FAULT_FLAG_ALLOW_RETRY) {
102                         if (fault & VM_FAULT_RETRY) {
103                                 flags |= FAULT_FLAG_TRIED;
104                                 goto retry;
105                         }
106                 }
107 
108                 mmap_read_unlock(mm);
109                 return;
110         }
111 
112         mmap_read_unlock(mm);
113 
114         /* Handle copyin/out exception cases */
115         if (!user_mode(regs))
116                 goto no_context;
117 
118         if (fault & VM_FAULT_OOM) {
119                 pagefault_out_of_memory();
120                 return;
121         }
122 
123         /* User-mode address is in the memory map, but we are
124          * unable to fix up the page fault.
125          */
126         if (fault & VM_FAULT_SIGBUS) {
127                 si_signo = SIGBUS;
128                 si_code = BUS_ADRERR;
129         }
130         /* Address is not in the memory map */
131         else {
132                 si_signo = SIGSEGV;
133                 si_code  = SEGV_ACCERR;
134         }
135         force_sig_fault(si_signo, si_code, (void __user *)address);
136         return;
137 
138 bad_area:
139         mmap_read_unlock(mm);
140 
141         if (user_mode(regs)) {
142                 force_sig_fault(SIGSEGV, si_code, (void __user *)address);
143                 return;
144         }
145         /* Kernel-mode fault falls through */
146 
147 no_context:
148         fixup = search_exception_tables(pt_elr(regs));
149         if (fixup) {
150                 pt_set_elr(regs, fixup->fixup);
151                 return;
152         }
153 
154         /* Things are looking very, very bad now */
155         bust_spinlocks(1);
156         printk(KERN_EMERG "Unable to handle kernel paging request at "
157                 "virtual address 0x%08lx, regs %p\n", address, regs);
158         die("Bad Kernel VA", regs, SIGKILL);
159 }
160 
161 
162 void read_protection_fault(struct pt_regs *regs)
163 {
164         unsigned long badvadr = pt_badva(regs);
165 
166         do_page_fault(badvadr, FLT_LOAD, regs);
167 }
168 
169 void write_protection_fault(struct pt_regs *regs)
170 {
171         unsigned long badvadr = pt_badva(regs);
172 
173         do_page_fault(badvadr, FLT_STORE, regs);
174 }
175 
176 void execute_protection_fault(struct pt_regs *regs)
177 {
178         unsigned long badvadr = pt_badva(regs);
179 
180         do_page_fault(badvadr, FLT_IFETCH, regs);
181 }
182 

~ [ 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