Orange Pi5 kernel

^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)  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/hardirq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/sched/debug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <asm/current.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <asm/tlbflush.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <arch.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <as-layout.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <kern_util.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <os.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <skas.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  * Note this is constrained to return 0, -EFAULT, -EACCES, -ENOMEM by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  * segv().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) int handle_page_fault(unsigned long address, unsigned long ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 		      int is_write, int is_user, int *code_out)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	struct mm_struct *mm = current->mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	struct vm_area_struct *vma;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	pmd_t *pmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	pte_t *pte;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	int err = -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	unsigned int flags = FAULT_FLAG_DEFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	*code_out = SEGV_MAPERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	 * If the fault was with pagefaults disabled, don't take the fault, just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	 * fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	if (faulthandler_disabled())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		goto out_nosemaphore;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	if (is_user)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		flags |= FAULT_FLAG_USER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) retry:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	mmap_read_lock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	vma = find_vma(mm, address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	if (!vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	else if (vma->vm_start <= address)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 		goto good_area;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	else if (!(vma->vm_flags & VM_GROWSDOWN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	else if (is_user && !ARCH_IS_STACKGROW(address))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	else if (expand_stack(vma, address))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) good_area:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	*code_out = SEGV_ACCERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	if (is_write) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 		if (!(vma->vm_flags & VM_WRITE))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 		flags |= FAULT_FLAG_WRITE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		/* Don't require VM_READ|VM_EXEC for write faults! */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 		vm_fault_t fault;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 		fault = handle_mm_fault(vma, address, flags, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 		if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 			goto out_nosemaphore;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 		if (unlikely(fault & VM_FAULT_ERROR)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 			if (fault & VM_FAULT_OOM) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 				goto out_of_memory;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 			} else if (fault & VM_FAULT_SIGSEGV) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 				goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 			} else if (fault & VM_FAULT_SIGBUS) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 				err = -EACCES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 				goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 			BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		if (flags & FAULT_FLAG_ALLOW_RETRY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 			if (fault & VM_FAULT_RETRY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 				flags |= FAULT_FLAG_TRIED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 				goto retry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		pmd = pmd_off(mm, address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		pte = pte_offset_kernel(pmd, address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	} while (!pte_present(*pte));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	 * The below warning was added in place of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	 *	pte_mkyoung(); if (is_write) pte_mkdirty();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	 * If it's triggered, we'd see normally a hang here (a clean pte is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	 * marked read-only to emulate the dirty bit).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	 * However, the generic code can mark a PTE writable but clean on a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	 * concurrent read fault, triggering this harmlessly. So comment it out.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) #if 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	WARN_ON(!pte_young(*pte) || (is_write && !pte_dirty(*pte)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	flush_tlb_page(vma, address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	mmap_read_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) out_nosemaphore:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) out_of_memory:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	 * We ran out of memory, call the OOM killer, and return the userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	 * (which will retry the fault, or kill us if we got oom-killed).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	mmap_read_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	if (!is_user)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		goto out_nosemaphore;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	pagefault_out_of_memory();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) EXPORT_SYMBOL(handle_page_fault);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) static void show_segv_info(struct uml_pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	struct task_struct *tsk = current;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	struct faultinfo *fi = UPT_FAULTINFO(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	if (!unhandled_signal(tsk, SIGSEGV))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	if (!printk_ratelimit())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	printk("%s%s[%d]: segfault at %lx ip %px sp %px error %x",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 		tsk->comm, task_pid_nr(tsk), FAULT_ADDRESS(*fi),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		(void *)UPT_IP(regs), (void *)UPT_SP(regs),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		fi->error_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	print_vma_addr(KERN_CONT " in ", UPT_IP(regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	printk(KERN_CONT "\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) static void bad_segv(struct faultinfo fi, unsigned long ip)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	current->thread.arch.faultinfo = fi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	force_sig_fault(SIGSEGV, SEGV_ACCERR, (void __user *) FAULT_ADDRESS(fi));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) void fatal_sigsegv(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	force_sigsegv(SIGSEGV);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	do_signal(&current->thread.regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	 * This is to tell gcc that we're not returning - do_signal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	 * can, in general, return, but in this case, it's not, since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	 * we just got a fatal SIGSEGV queued.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	os_dump_core();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)  * segv_handler() - the SIGSEGV handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)  * @sig:	the signal number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)  * @unused_si:	the signal info struct; unused in this handler
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)  * @regs:	the ptrace register information
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)  * The handler first extracts the faultinfo from the UML ptrace regs struct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)  * If the userfault did not happen in an UML userspace process, bad_segv is called.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)  * Otherwise the signal did happen in a cloned userspace process, handle it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	struct faultinfo * fi = UPT_FAULTINFO(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	if (UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		show_segv_info(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		bad_segv(*fi, UPT_IP(regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)  * We give a *copy* of the faultinfo in the regs to segv.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)  * This must be done, since nesting SEGVs could overwrite
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)  * the info in the regs. A pointer to the info then would
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)  * give us bad data!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		   struct uml_pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	jmp_buf *catcher;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	int si_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	int is_write = FAULT_WRITE(fi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	unsigned long address = FAULT_ADDRESS(fi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	if (!is_user && regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		current->thread.segv_regs = container_of(regs, struct pt_regs, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	if (!is_user && (address >= start_vm) && (address < end_vm)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		flush_tlb_kernel_vm();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	else if (current->mm == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 		show_regs(container_of(regs, struct pt_regs, regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 		panic("Segfault with no mm");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	else if (!is_user && address > PAGE_SIZE && address < TASK_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		show_regs(container_of(regs, struct pt_regs, regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 		panic("Kernel tried to access user memory at addr 0x%lx, ip 0x%lx",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 		       address, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	if (SEGV_IS_FIXABLE(&fi))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 		err = handle_page_fault(address, ip, is_write, is_user,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 					&si_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		err = -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 		 * A thread accessed NULL, we get a fault, but CR2 is invalid.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 		 * This code is used in __do_copy_from_user() of TT mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 		 * XXX tt mode is gone, so maybe this isn't needed any more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 		address = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	catcher = current->thread.fault_catcher;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	if (!err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	else if (catcher != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 		current->thread.fault_addr = (void *) address;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		UML_LONGJMP(catcher, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	else if (current->thread.fault_addr != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		panic("fault_addr set but no fault catcher");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	else if (!is_user && arch_fixup(ip, regs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	if (!is_user) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 		show_regs(container_of(regs, struct pt_regs, regs));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 		panic("Kernel mode fault at addr 0x%lx, ip 0x%lx",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 		      address, ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	show_segv_info(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	if (err == -EACCES) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 		current->thread.arch.faultinfo = fi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 		force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 		BUG_ON(err != -EFAULT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 		current->thread.arch.faultinfo = fi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 		force_sig_fault(SIGSEGV, si_code, (void __user *) address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	if (regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		current->thread.segv_regs = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	int code, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	if (!UPT_IS_USER(regs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 		if (sig == SIGBUS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 			printk(KERN_ERR "Bus error - the host /dev/shm or /tmp "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 			       "mount likely just ran out of space\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 		panic("Kernel mode signal %d", sig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	arch_examine_signal(sig, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	/* Is the signal layout for the signal known?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 	 * Signal data must be scrubbed to prevent information leaks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	code = si->si_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	err = si->si_errno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	if ((err == 0) && (siginfo_layout(sig, code) == SIL_FAULT)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		struct faultinfo *fi = UPT_FAULTINFO(regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 		current->thread.arch.faultinfo = *fi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 		force_sig_fault(sig, code, (void __user *)FAULT_ADDRESS(*fi));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 		printk(KERN_ERR "Attempted to relay unknown signal %d (si_code = %d) with errno %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 		       sig, code, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		force_sig(sig);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) void bus_handler(int sig, struct siginfo *si, struct uml_pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 	if (current->thread.fault_catcher != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 		UML_LONGJMP(current->thread.fault_catcher, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 		relay_signal(sig, si, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) void winch(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 	do_IRQ(WINCH_IRQ, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) void trap_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) }