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08582d678f
Overlayfs uses backing files with "fake" overlayfs f_path and "real" underlying f_inode, in order to use underlying inode aops for mapped files and to display the overlayfs path in /proc/<pid>/maps. In preparation for storing the overlayfs "fake" path instead of the underlying "real" path in struct backing_file, define a noop helper file_user_path() that returns f_path for now. Use the new helper in procfs and kernel logs whenever a path of a mapped file is displayed to users. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20231009153712.1566422-3-amir73il@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
231 lines
6.2 KiB
C
231 lines
6.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*/
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#include <linux/ptrace.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/kdev_t.h>
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#include <linux/proc_fs.h>
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#include <linux/file.h>
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#include <linux/sched/mm.h>
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#include <linux/sched/debug.h>
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#include <asm/arcregs.h>
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#include <asm/irqflags.h>
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#define ARC_PATH_MAX 256
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static noinline void print_regs_scratch(struct pt_regs *regs)
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{
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pr_cont("BTA: 0x%08lx\n SP: 0x%08lx FP: 0x%08lx BLK: %pS\n",
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regs->bta, regs->sp, regs->fp, (void *)regs->blink);
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pr_cont("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
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regs->lp_start, regs->lp_end, regs->lp_count);
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pr_info("r00: 0x%08lx\tr01: 0x%08lx\tr02: 0x%08lx\n" \
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"r03: 0x%08lx\tr04: 0x%08lx\tr05: 0x%08lx\n" \
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"r06: 0x%08lx\tr07: 0x%08lx\tr08: 0x%08lx\n" \
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"r09: 0x%08lx\tr10: 0x%08lx\tr11: 0x%08lx\n" \
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"r12: 0x%08lx\t",
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regs->r0, regs->r1, regs->r2,
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regs->r3, regs->r4, regs->r5,
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regs->r6, regs->r7, regs->r8,
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regs->r9, regs->r10, regs->r11,
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regs->r12);
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}
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static void print_regs_callee(struct callee_regs *regs)
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{
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pr_cont("r13: 0x%08lx\tr14: 0x%08lx\n" \
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"r15: 0x%08lx\tr16: 0x%08lx\tr17: 0x%08lx\n" \
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"r18: 0x%08lx\tr19: 0x%08lx\tr20: 0x%08lx\n" \
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"r21: 0x%08lx\tr22: 0x%08lx\tr23: 0x%08lx\n" \
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"r24: 0x%08lx\tr25: 0x%08lx\n",
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regs->r13, regs->r14,
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regs->r15, regs->r16, regs->r17,
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regs->r18, regs->r19, regs->r20,
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regs->r21, regs->r22, regs->r23,
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regs->r24, regs->r25);
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}
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static void print_task_path_n_nm(struct task_struct *tsk)
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{
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char *path_nm = NULL;
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struct mm_struct *mm;
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struct file *exe_file;
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char buf[ARC_PATH_MAX];
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mm = get_task_mm(tsk);
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if (!mm)
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goto done;
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exe_file = get_mm_exe_file(mm);
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mmput(mm);
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if (exe_file) {
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path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1);
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fput(exe_file);
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}
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done:
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pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
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}
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static void show_faulting_vma(unsigned long address)
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{
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struct vm_area_struct *vma;
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struct mm_struct *active_mm = current->active_mm;
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/* can't use print_vma_addr() yet as it doesn't check for
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* non-inclusive vma
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*/
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mmap_read_lock(active_mm);
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vma = vma_lookup(active_mm, address);
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/* Lookup the vma at the address and report if the container VMA is not
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* found
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*/
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if (vma) {
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char buf[ARC_PATH_MAX];
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char *nm = "anon";
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if (vma->vm_file) {
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/* XXX: can we use %pD below and get rid of buf? */
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nm = d_path(file_user_path(vma->vm_file), buf,
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ARC_PATH_MAX-1);
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if (IS_ERR(nm))
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nm = "?";
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}
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pr_info(" @off 0x%lx in [%s] VMA: 0x%08lx to 0x%08lx\n",
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vma->vm_start < TASK_UNMAPPED_BASE ?
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address : address - vma->vm_start,
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nm, vma->vm_start, vma->vm_end);
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} else
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pr_info(" @No matching VMA found\n");
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mmap_read_unlock(active_mm);
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}
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static void show_ecr_verbose(struct pt_regs *regs)
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{
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unsigned int vec, cause_code;
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unsigned long address;
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/* For Data fault, this is data address not instruction addr */
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address = current->thread.fault_address;
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vec = regs->ecr.vec;
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cause_code = regs->ecr.cause;
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/* For DTLB Miss or ProtV, display the memory involved too */
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if (vec == ECR_V_DTLB_MISS) {
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pr_cont("Invalid %s @ 0x%08lx by insn @ %pS\n",
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(cause_code == 0x01) ? "Read" :
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((cause_code == 0x02) ? "Write" : "EX"),
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address, (void *)regs->ret);
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} else if (vec == ECR_V_ITLB_MISS) {
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pr_cont("Insn could not be fetched\n");
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} else if (vec == ECR_V_MACH_CHK) {
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pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
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"Double Fault" : "Other Fatal Err");
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} else if (vec == ECR_V_PROTV) {
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if (cause_code == ECR_C_PROTV_INST_FETCH)
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pr_cont("Execute from Non-exec Page\n");
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else if (cause_code == ECR_C_PROTV_MISALIG_DATA &&
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IS_ENABLED(CONFIG_ISA_ARCOMPACT))
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pr_cont("Misaligned r/w from 0x%08lx\n", address);
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else
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pr_cont("%s access not allowed on page\n",
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(cause_code == 0x01) ? "Read" :
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((cause_code == 0x02) ? "Write" : "EX"));
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} else if (vec == ECR_V_INSN_ERR) {
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pr_cont("Illegal Insn\n");
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#ifdef CONFIG_ISA_ARCV2
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} else if (vec == ECR_V_MEM_ERR) {
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if (cause_code == 0x00)
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pr_cont("Bus Error from Insn Mem\n");
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else if (cause_code == 0x10)
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pr_cont("Bus Error from Data Mem\n");
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else
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pr_cont("Bus Error, check PRM\n");
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} else if (vec == ECR_V_MISALIGN) {
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pr_cont("Misaligned r/w from 0x%08lx\n", address);
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#endif
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} else if (vec == ECR_V_TRAP) {
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if (regs->ecr.param == 5)
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pr_cont("gcc generated __builtin_trap\n");
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} else {
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pr_cont("Check Programmer's Manual\n");
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}
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}
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/************************************************************************
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* API called by rest of kernel
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***********************************************************************/
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void show_regs(struct pt_regs *regs)
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{
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struct task_struct *tsk = current;
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struct callee_regs *cregs = (struct callee_regs *)tsk->thread.callee_reg;
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/*
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* generic code calls us with preemption disabled, but some calls
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* here could sleep, so re-enable to avoid lockdep splat
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*/
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preempt_enable();
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print_task_path_n_nm(tsk);
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show_regs_print_info(KERN_INFO);
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show_ecr_verbose(regs);
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if (user_mode(regs))
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show_faulting_vma(regs->ret); /* faulting code, not data */
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pr_info("ECR: 0x%08lx EFA: 0x%08lx ERET: 0x%08lx\n",
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regs->ecr.full, current->thread.fault_address, regs->ret);
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pr_info("STAT32: 0x%08lx", regs->status32);
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#define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
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#ifdef CONFIG_ISA_ARCOMPACT
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pr_cont(" [%2s%2s%2s%2s%2s%2s%2s]",
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(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
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STS_BIT(regs, DE), STS_BIT(regs, AE),
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STS_BIT(regs, A2), STS_BIT(regs, A1),
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STS_BIT(regs, E2), STS_BIT(regs, E1));
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#else
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pr_cont(" [%2s%2s%2s%2s] ",
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STS_BIT(regs, IE),
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(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
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STS_BIT(regs, DE), STS_BIT(regs, AE));
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#endif
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print_regs_scratch(regs);
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if (cregs)
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print_regs_callee(cregs);
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preempt_disable();
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}
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void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
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unsigned long address)
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{
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current->thread.fault_address = address;
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/* Show fault description */
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pr_info("\n%s\n", str);
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/* Caller and Callee regs */
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show_regs(regs);
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/* Show stack trace if this Fatality happened in kernel mode */
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if (!user_mode(regs))
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show_stacktrace(current, regs, KERN_DEFAULT);
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}
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