50 #include <asm/text-patching.h>
65 #include <asm/insn-eval.h>
68 #include <asm/cfi.h>
73 #include <asm/processor-flags.h>
94  * Check for UD1 or UD2, accounting for Address Size Override Prefixes.
152 		tsk->thread.error_code = error_code;  in do_trap_no_signal()
153 		tsk->thread.trap_nr = trapnr;  in do_trap_no_signal()
169 	tsk->thread.error_code = error_code;  in do_trap_no_signal()
170 	tsk->thread.trap_nr = trapnr;  in do_trap_no_signal()
172 	return -1;  in do_trap_no_signal()
182 			tsk->comm, task_pid_nr(tsk), type, desc,  in show_signal()
183 			regs->ip, regs->sp, error_code);  in show_signal()
184 		print_vma_addr(KERN_CONT " in ", regs->ip);  in show_signal()
224  * This address is usually regs->ip, but when an uprobe moved the code out
225  * of line then regs->ip points to the XOL code which would confuse
227  * a trap happened in XOL code then uprobe maps regs->ip back to the
262 	ud_type = decode_bug(regs->ip, &imm);  in handle_bug()
280 	if (regs->flags & X86_EFLAGS_IF)  in handle_bug()
283 		if (report_bug(regs->ip, regs) == BUG_TRAP_TYPE_WARN ||  in handle_bug()
285 			regs->ip += LEN_UD2;  in handle_bug()
289 		pr_crit("%s at %pS\n", report_ubsan_failure(regs, imm), (void *)regs->ip);  in handle_bug()
291 	if (regs->flags & X86_EFLAGS_IF)  in handle_bug()
343 	char *str = "alignment check";  in DEFINE_IDTENTRY_ERRORCODE()
356 	do_trap(X86_TRAP_AC, SIGBUS, "alignment check", regs,  in DEFINE_IDTENTRY_ERRORCODE()
368 	const char *name = stack_type_name(info->type);  in handle_stack_overflow()
371 	       name, (void *)fault_address, info->begin, info->end);  in handle_stack_overflow()
381  * Runs on an IST stack for x86_64 and on a special task stack for x86_32.
383  * On x86_64, this is more or less a normal kernel entry.  Notwithstanding the
389  * while the stack is read-only are, in fact, recoverable.
413 	 * If IRET takes a non-IST fault on the espfix64 stack, then we  in DEFINE_IDTENTRY_DF()
426 	if (((long)regs->sp >> P4D_SHIFT) == ESPFIX_PGD_ENTRY &&  in DEFINE_IDTENTRY_DF()
427 		regs->cs == __KERNEL_CS &&  in DEFINE_IDTENTRY_DF()
428 		regs->ip == (unsigned long)native_irq_return_iret)  in DEFINE_IDTENTRY_DF()
430 		struct pt_regs *gpregs = (struct pt_regs *)this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1;  in DEFINE_IDTENTRY_DF()
431 		unsigned long *p = (unsigned long *)regs->sp;  in DEFINE_IDTENTRY_DF()
434 		 * regs->sp points to the failing IRET frame on the  in DEFINE_IDTENTRY_DF()
436 		 * in gpregs->ss through gpregs->ip.  in DEFINE_IDTENTRY_DF()
439 		gpregs->ip	= p[0];  in DEFINE_IDTENTRY_DF()
440 		gpregs->cs	= p[1];  in DEFINE_IDTENTRY_DF()
441 		gpregs->flags	= p[2];  in DEFINE_IDTENTRY_DF()
442 		gpregs->sp	= p[3];  in DEFINE_IDTENTRY_DF()
443 		gpregs->ss	= p[4];  in DEFINE_IDTENTRY_DF()
444 		gpregs->orig_ax = 0;  /* Missing (lost) #GP error code */  in DEFINE_IDTENTRY_DF()
457 		regs->ip = (unsigned long)asm_exc_general_protection;  in DEFINE_IDTENTRY_DF()
458 		regs->sp = (unsigned long)&gpregs->orig_ax;  in DEFINE_IDTENTRY_DF()
468 	tsk->thread.error_code = error_code;  in DEFINE_IDTENTRY_DF()
469 	tsk->thread.trap_nr = X86_TRAP_DF;  in DEFINE_IDTENTRY_DF()
475 	 * take any non-IST exception while too close to the bottom of  in DEFINE_IDTENTRY_DF()
479 	 * According to the SDM (footnote in 6.15 under "Interrupt 14 -  in DEFINE_IDTENTRY_DF()
480 	 * Page-Fault Exception (#PF):  in DEFINE_IDTENTRY_DF()
543  * out whether any part of the access to that address was non-canonical.
552 	if (copy_from_kernel_nofault(insn_buf, (void *)regs->ip,  in get_kernel_gp_address()
561 	if (*addr == -1UL)  in get_kernel_gp_address()
566 	 * Check that:  in get_kernel_gp_address()
567 	 *  - the operand is not in the kernel half  in get_kernel_gp_address()
568 	 *  - the last byte of the operand is not in the user canonical half  in get_kernel_gp_address()
571 	    *addr + insn.opnd_bytes - 1 > __VIRTUAL_MASK)  in get_kernel_gp_address()
582 	struct thread_struct *t = &current->thread;  in fixup_iopl_exception()
586 	if (!IS_ENABLED(CONFIG_X86_IOPL_IOPERM) || t->iopl_emul != 3)  in fixup_iopl_exception()
598 	if (!t->iopl_warn && printk_ratelimit()) {  in fixup_iopl_exception()
600 		       current->comm, task_pid_nr(current), ip);  in fixup_iopl_exception()
603 		t->iopl_warn = 1;  in fixup_iopl_exception()
606 	regs->ip += 1;  in fixup_iopl_exception()
625 	 * in *before* interrupts are re-enabled.  in try_fixup_enqcmd_gp()
640 	if (!mm_valid_pasid(current->mm))  in try_fixup_enqcmd_gp()
643 	pasid = current->mm->pasid;  in try_fixup_enqcmd_gp()
649 	if (current->pasid_activated)  in try_fixup_enqcmd_gp()
653 	current->pasid_activated = 1;  in try_fixup_enqcmd_gp()
668 	current->thread.error_code = error_code;  in gp_try_fixup_and_notify()
669 	current->thread.trap_nr = trapnr;  in gp_try_fixup_and_notify()
673 	 * from kprobe_running(), we have to be non-preemptible.  in gp_try_fixup_and_notify()
685 	current->thread.error_code = error_code;  in gp_user_force_sig_segv()
686 	current->thread.trap_nr = trapnr;  in gp_user_force_sig_segv()
729 		snprintf(desc, sizeof(desc), "segment-related " GPFSTR);  in DEFINE_IDTENTRY_ERRORCODE()
735 			 (hint == GP_NON_CANONICAL) ? "probably for non-canonical address"  in DEFINE_IDTENTRY_ERRORCODE()
740 	 * KASAN is interested only in the non-canonical case, clear it  in DEFINE_IDTENTRY_ERRORCODE()
818  * Help handler running on a per-cpu (IST or entry trampoline) stack
824 	struct pt_regs *regs = (struct pt_regs *)this_cpu_read(pcpu_hot.top_of_stack) - 1;  in sync_regs()
838 	 * In the SYSCALL entry path the RSP value comes from user-space - don't  in vc_switch_off_ist()
847 	 * From here on the RSP value is trusted. Now check whether entry  in vc_switch_off_ist()
849 	 * use the fall-back stack instead in this case.  in vc_switch_off_ist()
851 	sp    = regs->sp;  in vc_switch_off_ist()
860 	 * Found a safe stack - switch to it as if the entry didn't happen via  in vc_switch_off_ist()
864 	sp = ALIGN_DOWN(sp, 8) - sizeof(*regs_ret);  in vc_switch_off_ist()
885 	new_stack = (struct pt_regs *)__this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1;  in fixup_bad_iret()
888 	__memcpy(&tmp.ip, (void *)bad_regs->sp, 5*8);  in fixup_bad_iret()
905 	 * code that can be single-stepped in the SYSENTER entry path, then  in is_sysenter_singlestep()
906 	 * assume that this is a useless single-step trap due to SYSENTER  in is_sysenter_singlestep()
912 	return (regs->ip - (unsigned long)__begin_SYSENTER_singlestep_region) <  in is_sysenter_singlestep()
913 		(unsigned long)__end_SYSENTER_singlestep_region -  in is_sysenter_singlestep()
916 	return (regs->ip - (unsigned long)entry_SYSENTER_compat) <  in is_sysenter_singlestep()
917 		(unsigned long)__end_entry_SYSENTER_compat -  in is_sysenter_singlestep()
931 	 *   Certain debug exceptions may clear bits 0-3. The remaining  in debug_read_clear_dr6()
947  * Our handling of the processor debug registers is non-trivial.
951  * only set watchpoints on userspace addresses. Therefore the in-kernel
975 	 * consumed - hw_breakpoint_handler(), single_stop_cont().  in notify_debug()
978 	 * for signals - ptrace_triggered(), kgdb_hw_overflow_handler().  in notify_debug()
1014 		 * it for userspace, but we just took a kernel #DB, so re-set  in exc_debug_kernel()
1041 	 * The kernel doesn't use TF single-step outside of:  in exc_debug_kernel()
1043 	 *  - Kprobes, consumed through kprobe_debug_handler()  in exc_debug_kernel()
1044 	 *  - KGDB, consumed through notify_debug()  in exc_debug_kernel()
1052 		regs->flags &= ~X86_EFLAGS_TF;  in exc_debug_kernel()
1090 	current->thread.virtual_dr6 = (dr6 & DR_STEP);  in exc_debug_user()
1122 	dr6 |= current->thread.virtual_dr6;  in exc_debug_user()
1166 	struct fpu *fpu = &task->thread.fpu;  in math_error()
1177 		task->thread.error_code = 0;  in math_error()
1178 		task->thread.trap_nr = trapnr;  in math_error()
1192 	task->thread.trap_nr	= trapnr;  in math_error()
1193 	task->thread.error_code = 0;  in math_error()
1272 	case -EPERM:  in handle_xfd_event()
1275 	case -EFAULT:  in handle_xfd_event()
1312 		 * to kill the task than getting stuck in a never-ending  in DEFINE_IDTENTRY()
1350  * never generated on accesses to normal, TD-private memory that has been
1357  * IRET will re-enable NMIs and nested NMI will corrupt the NMI stack.
1360  * the NMI entry code. Entry code paths do not access TD-shared memory,
1374  * the interrupt-disabled region before TDGETVEINFO, a #DF (fault
1387 	 * NMIs/Machine-checks/Interrupts will be in a disabled state  in DEFINE_IDTENTRY()
1425 	/* Init GHCB memory pages when running as an SEV-ES guest */  in trap_init()