forked from Minki/linux
5ad18b2e60
Pull force_sig() argument change from Eric Biederman: "A source of error over the years has been that force_sig has taken a task parameter when it is only safe to use force_sig with the current task. The force_sig function is built for delivering synchronous signals such as SIGSEGV where the userspace application caused a synchronous fault (such as a page fault) and the kernel responded with a signal. Because the name force_sig does not make this clear, and because the force_sig takes a task parameter the function force_sig has been abused for sending other kinds of signals over the years. Slowly those have been fixed when the oopses have been tracked down. This set of changes fixes the remaining abusers of force_sig and carefully rips out the task parameter from force_sig and friends making this kind of error almost impossible in the future" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits) signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus signal: Remove the signal number and task parameters from force_sig_info signal: Factor force_sig_info_to_task out of force_sig_info signal: Generate the siginfo in force_sig signal: Move the computation of force into send_signal and correct it. signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal signal: Remove the task parameter from force_sig_fault signal: Use force_sig_fault_to_task for the two calls that don't deliver to current signal: Explicitly call force_sig_fault on current signal/unicore32: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from ptrace_break signal/nds32: Remove tsk parameter from send_sigtrap signal/riscv: Remove tsk parameter from do_trap signal/sh: Remove tsk parameter from force_sig_info_fault signal/um: Remove task parameter from send_sigtrap signal/x86: Remove task parameter from send_sigtrap signal: Remove task parameter from force_sig_mceerr signal: Remove task parameter from force_sig signal: Remove task parameter from force_sigsegv ...
165 lines
4.1 KiB
C
165 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Traps/Non-MMU Exception handling for ARC
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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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* vineetg: May 2011
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* -user-space unaligned access emulation
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*
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* Rahul Trivedi: Codito Technologies 2004
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*/
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#include <linux/sched/signal.h>
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#include <linux/kdebug.h>
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#include <linux/uaccess.h>
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#include <linux/ptrace.h>
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#include <linux/kprobes.h>
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#include <linux/kgdb.h>
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#include <asm/setup.h>
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#include <asm/unaligned.h>
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#include <asm/kprobes.h>
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void __init trap_init(void)
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{
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return;
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}
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void die(const char *str, struct pt_regs *regs, unsigned long address)
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{
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show_kernel_fault_diag(str, regs, address);
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/* DEAD END */
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__asm__("flag 1");
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}
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/*
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* Helper called for bulk of exceptions NOT needing specific handling
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* -for user faults enqueues requested signal
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* -for kernel, chk if due to copy_(to|from)_user, otherwise die()
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*/
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static noinline int
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unhandled_exception(const char *str, struct pt_regs *regs,
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int signo, int si_code, void __user *addr)
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{
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if (user_mode(regs)) {
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struct task_struct *tsk = current;
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tsk->thread.fault_address = (__force unsigned int)addr;
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force_sig_fault(signo, si_code, addr);
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} else {
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/* If not due to copy_(to|from)_user, we are doomed */
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if (fixup_exception(regs))
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return 0;
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die(str, regs, (unsigned long)addr);
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}
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return 1;
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}
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#define DO_ERROR_INFO(signr, str, name, sicode) \
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int name(unsigned long address, struct pt_regs *regs) \
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{ \
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return unhandled_exception(str, regs, signr, sicode, \
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(void __user *)address); \
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}
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/*
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* Entry points for exceptions NOT needing specific handling
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*/
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DO_ERROR_INFO(SIGILL, "Priv Op/Disabled Extn", do_privilege_fault, ILL_PRVOPC)
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DO_ERROR_INFO(SIGILL, "Invalid Extn Insn", do_extension_fault, ILL_ILLOPC)
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DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC)
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DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", __weak do_memory_error, BUS_ADRERR)
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DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT)
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DO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN)
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DO_ERROR_INFO(SIGSEGV, "gcc generated __builtin_trap", do_trap5_error, 0)
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/*
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* Entry Point for Misaligned Data access Exception, for emulating in software
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*/
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int do_misaligned_access(unsigned long address, struct pt_regs *regs,
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struct callee_regs *cregs)
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{
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/* If emulation not enabled, or failed, kill the task */
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if (misaligned_fixup(address, regs, cregs) != 0)
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return do_misaligned_error(address, regs);
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return 0;
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}
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/*
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* Entry point for miscll errors such as Nested Exceptions
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* -Duplicate TLB entry is handled seperately though
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*/
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void do_machine_check_fault(unsigned long address, struct pt_regs *regs)
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{
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die("Unhandled Machine Check Exception", regs, address);
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}
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/*
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* Entry point for traps induced by ARCompact TRAP_S <n> insn
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* This is same family as TRAP0/SWI insn (use the same vector).
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* The only difference being SWI insn take no operand, while TRAP_S does
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* which reflects in ECR Reg as 8 bit param.
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* Thus TRAP_S <n> can be used for specific purpose
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* -1 used for software breakpointing (gdb)
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* -2 used by kprobes
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* -5 __builtin_trap() generated by gcc (2018.03 onwards) for toggle such as
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* -fno-isolate-erroneous-paths-dereference
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*/
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void do_non_swi_trap(unsigned long address, struct pt_regs *regs)
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{
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unsigned int param = regs->ecr_param;
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switch (param) {
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case 1:
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trap_is_brkpt(address, regs);
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break;
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case 2:
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trap_is_kprobe(address, regs);
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break;
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case 3:
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case 4:
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kgdb_trap(regs);
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break;
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case 5:
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do_trap5_error(address, regs);
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break;
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default:
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break;
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}
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}
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/*
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* Entry point for Instruction Error Exception
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* -For a corner case, ARC kprobes implementation resorts to using
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* this exception, hence the check
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*/
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void do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs)
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{
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int rc;
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/* Check if this exception is caused by kprobes */
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rc = notify_die(DIE_IERR, "kprobe_ierr", regs, address, 0, SIGILL);
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if (rc == NOTIFY_STOP)
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return;
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insterror_is_error(address, regs);
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}
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/*
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* abort() call generated by older gcc for __builtin_trap()
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*/
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void abort(void)
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{
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__asm__ __volatile__("trap_s 5\n");
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}
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