^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * linux/arch/m68k/mm/fault.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 1995 Hamish Macdonald
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/mman.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/ptrace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/perf_event.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <asm/setup.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <asm/traps.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) extern void die_if_kernel(char *, struct pt_regs *, long);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) int send_fault_sig(struct pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) int signo, si_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) void __user *addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) signo = current->thread.signo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) si_code = current->thread.code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) addr = (void __user *)current->thread.faddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) pr_debug("send_fault_sig: %p,%d,%d\n", addr, signo, si_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) if (user_mode(regs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) force_sig_fault(signo, si_code, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) if (fixup_exception(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) //if (signo == SIGBUS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) // force_sig_fault(si_signo, si_code, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * Oops. The kernel tried to access some bad page. We'll have to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * terminate things with extreme prejudice.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if ((unsigned long)addr < PAGE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) pr_alert("Unable to handle kernel NULL pointer dereference");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) pr_alert("Unable to handle kernel access");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) pr_cont(" at virtual address %p\n", addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) die_if_kernel("Oops", regs, 0 /*error_code*/);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) do_exit(SIGKILL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * This routine handles page faults. It determines the problem, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * then passes it off to one of the appropriate routines.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * error_code:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * bit 0 == 0 means no page found, 1 means protection fault
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) * bit 1 == 0 means read, 1 means write
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * If this routine detects a bad access, it returns 1, otherwise it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * returns 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) int do_page_fault(struct pt_regs *regs, unsigned long address,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) unsigned long error_code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) struct mm_struct *mm = current->mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) struct vm_area_struct * vma;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) vm_fault_t fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) unsigned int flags = FAULT_FLAG_DEFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) pr_debug("do page fault:\nregs->sr=%#x, regs->pc=%#lx, address=%#lx, %ld, %p\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) regs->sr, regs->pc, address, error_code, mm ? mm->pgd : NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * If we're in an interrupt or have no user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * context, we must not take the fault..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (faulthandler_disabled() || !mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) goto no_context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) if (user_mode(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) flags |= FAULT_FLAG_USER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) retry:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) mmap_read_lock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) vma = find_vma(mm, address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) if (!vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) goto map_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) if (vma->vm_flags & VM_IO)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) goto acc_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) if (vma->vm_start <= address)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) goto good_area;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) if (!(vma->vm_flags & VM_GROWSDOWN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) goto map_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) if (user_mode(regs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) /* Accessing the stack below usp is always a bug. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) "+ 256" is there due to some instructions doing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) pre-decrement on the stack and that doesn't show up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) until later. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (address + 256 < rdusp())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) goto map_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) if (expand_stack(vma, address))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) goto map_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * Ok, we have a good vm_area for this memory access, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * we can handle it..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) good_area:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) pr_debug("do_page_fault: good_area\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) switch (error_code & 3) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) default: /* 3: write, present */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) case 2: /* write, not present */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) if (!(vma->vm_flags & VM_WRITE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) goto acc_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) flags |= FAULT_FLAG_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) case 1: /* read, present */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) goto acc_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) case 0: /* read, not present */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) if (unlikely(!vma_is_accessible(vma)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) goto acc_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) * If for any reason at all we couldn't handle the fault,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * make sure we exit gracefully rather than endlessly redo
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) * the fault.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) fault = handle_mm_fault(vma, address, flags, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) pr_debug("handle_mm_fault returns %x\n", fault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) if (fault_signal_pending(fault, regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) if (unlikely(fault & VM_FAULT_ERROR)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) if (fault & VM_FAULT_OOM)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) goto out_of_memory;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) else if (fault & VM_FAULT_SIGSEGV)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) goto map_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) else if (fault & VM_FAULT_SIGBUS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) goto bus_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) if (flags & FAULT_FLAG_ALLOW_RETRY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) if (fault & VM_FAULT_RETRY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) flags |= FAULT_FLAG_TRIED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * No need to mmap_read_unlock(mm) as we would
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) * have already released it in __lock_page_or_retry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * in mm/filemap.c.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) goto retry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) mmap_read_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * We ran out of memory, or some other thing happened to us that made
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * us unable to handle the page fault gracefully.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) out_of_memory:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) mmap_read_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) if (!user_mode(regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) goto no_context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) pagefault_out_of_memory();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) no_context:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) current->thread.signo = SIGBUS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) current->thread.faddr = address;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) return send_fault_sig(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) bus_err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) current->thread.signo = SIGBUS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) current->thread.code = BUS_ADRERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) current->thread.faddr = address;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) goto send_sig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) map_err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) current->thread.signo = SIGSEGV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) current->thread.code = SEGV_MAPERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) current->thread.faddr = address;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) goto send_sig;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) acc_err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) current->thread.signo = SIGSEGV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) current->thread.code = SEGV_ACCERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) current->thread.faddr = address;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) send_sig:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) mmap_read_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) return send_fault_sig(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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