Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 403 insertions, 0 deletions

diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
new file mode 100644
index 0000000000..1d2aa448d1
--- /dev/null
+++ b/arch/s390/kernel/traps.c
@@ -0,0 +1,403 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  S390 version
+ *    Copyright IBM Corp. 1999, 2000
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
+ *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
+ *
+ *  Derived from "arch/i386/kernel/traps.c"
+ *    Copyright (C) 1991, 1992 Linus Torvalds
+ */
+
+/*
+ * 'Traps.c' handles hardware traps and faults after we have saved some
+ * state in 'asm.s'.
+ */
+#include "asm/irqflags.h"
+#include "asm/ptrace.h"
+#include <linux/kprobes.h>
+#include <linux/kdebug.h>
+#include <linux/randomize_kstack.h>
+#include <linux/extable.h>
+#include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/cpu.h>
+#include <linux/entry-common.h>
+#include <asm/asm-extable.h>
+#include <asm/fpu/api.h>
+#include <asm/vtime.h>
+#include "entry.h"
+
+static inline void __user *get_trap_ip(struct pt_regs *regs)
+{
+	unsigned long address;
+
+	if (regs->int_code & 0x200)
+		address = current->thread.trap_tdb.data[3];
+	else
+		address = regs->psw.addr;
+	return (void __user *) (address - (regs->int_code >> 16));
+}
+
+int is_valid_bugaddr(unsigned long addr)
+{
+	return 1;
+}
+
+void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
+{
+	if (user_mode(regs)) {
+		force_sig_fault(si_signo, si_code, get_trap_ip(regs));
+		report_user_fault(regs, si_signo, 0);
+        } else {
+		if (!fixup_exception(regs))
+			die(regs, str);
+        }
+}
+
+static void do_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
+{
+	if (notify_die(DIE_TRAP, str, regs, 0,
+		       regs->int_code, si_signo) == NOTIFY_STOP)
+		return;
+	do_report_trap(regs, si_signo, si_code, str);
+}
+NOKPROBE_SYMBOL(do_trap);
+
+void do_per_trap(struct pt_regs *regs)
+{
+	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
+		return;
+	if (!current->ptrace)
+		return;
+	force_sig_fault(SIGTRAP, TRAP_HWBKPT,
+		(void __force __user *) current->thread.per_event.address);
+}
+NOKPROBE_SYMBOL(do_per_trap);
+
+static void default_trap_handler(struct pt_regs *regs)
+{
+	if (user_mode(regs)) {
+		report_user_fault(regs, SIGSEGV, 0);
+		force_exit_sig(SIGSEGV);
+	} else
+		die(regs, "Unknown program exception");
+}
+
+#define DO_ERROR_INFO(name, signr, sicode, str) \
+static void name(struct pt_regs *regs)		\
+{						\
+	do_trap(regs, signr, sicode, str);	\
+}
+
+DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
+	      "addressing exception")
+DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
+	      "execute exception")
+DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
+	      "fixpoint divide exception")
+DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
+	      "fixpoint overflow exception")
+DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
+	      "HFP overflow exception")
+DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
+	      "HFP underflow exception")
+DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
+	      "HFP significance exception")
+DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
+	      "HFP divide exception")
+DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
+	      "HFP square root exception")
+DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
+	      "operand exception")
+DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
+	      "privileged operation")
+DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
+	      "special operation exception")
+DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
+	      "transaction constraint exception")
+
+static inline void do_fp_trap(struct pt_regs *regs, __u32 fpc)
+{
+	int si_code = 0;
+	/* FPC[2] is Data Exception Code */
+	if ((fpc & 0x00000300) == 0) {
+		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
+		if (fpc & 0x8000) /* invalid fp operation */
+			si_code = FPE_FLTINV;
+		else if (fpc & 0x4000) /* div by 0 */
+			si_code = FPE_FLTDIV;
+		else if (fpc & 0x2000) /* overflow */
+			si_code = FPE_FLTOVF;
+		else if (fpc & 0x1000) /* underflow */
+			si_code = FPE_FLTUND;
+		else if (fpc & 0x0800) /* inexact */
+			si_code = FPE_FLTRES;
+	}
+	do_trap(regs, SIGFPE, si_code, "floating point exception");
+}
+
+static void translation_specification_exception(struct pt_regs *regs)
+{
+	/* May never happen. */
+	panic("Translation-Specification Exception");
+}
+
+static void illegal_op(struct pt_regs *regs)
+{
+        __u8 opcode[6];
+	__u16 __user *location;
+	int is_uprobe_insn = 0;
+	int signal = 0;
+
+	location = get_trap_ip(regs);
+
+	if (user_mode(regs)) {
+		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
+			return;
+		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
+			if (current->ptrace)
+				force_sig_fault(SIGTRAP, TRAP_BRKPT, location);
+			else
+				signal = SIGILL;
+#ifdef CONFIG_UPROBES
+		} else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
+			is_uprobe_insn = 1;
+#endif
+		} else
+			signal = SIGILL;
+	}
+	/*
+	 * We got either an illegal op in kernel mode, or user space trapped
+	 * on a uprobes illegal instruction. See if kprobes or uprobes picks
+	 * it up. If not, SIGILL.
+	 */
+	if (is_uprobe_insn || !user_mode(regs)) {
+		if (notify_die(DIE_BPT, "bpt", regs, 0,
+			       3, SIGTRAP) != NOTIFY_STOP)
+			signal = SIGILL;
+	}
+	if (signal)
+		do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
+}
+NOKPROBE_SYMBOL(illegal_op);
+
+DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
+	      "specification exception");
+
+static void vector_exception(struct pt_regs *regs)
+{
+	int si_code, vic;
+
+	if (!MACHINE_HAS_VX) {
+		do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
+		return;
+	}
+
+	/* get vector interrupt code from fpc */
+	save_fpu_regs();
+	vic = (current->thread.fpu.fpc & 0xf00) >> 8;
+	switch (vic) {
+	case 1: /* invalid vector operation */
+		si_code = FPE_FLTINV;
+		break;
+	case 2: /* division by zero */
+		si_code = FPE_FLTDIV;
+		break;
+	case 3: /* overflow */
+		si_code = FPE_FLTOVF;
+		break;
+	case 4: /* underflow */
+		si_code = FPE_FLTUND;
+		break;
+	case 5:	/* inexact */
+		si_code = FPE_FLTRES;
+		break;
+	default: /* unknown cause */
+		si_code = 0;
+	}
+	do_trap(regs, SIGFPE, si_code, "vector exception");
+}
+
+static void data_exception(struct pt_regs *regs)
+{
+	save_fpu_regs();
+	if (current->thread.fpu.fpc & FPC_DXC_MASK)
+		do_fp_trap(regs, current->thread.fpu.fpc);
+	else
+		do_trap(regs, SIGILL, ILL_ILLOPN, "data exception");
+}
+
+static void space_switch_exception(struct pt_regs *regs)
+{
+	/* Set user psw back to home space mode. */
+	if (user_mode(regs))
+		regs->psw.mask |= PSW_ASC_HOME;
+	/* Send SIGILL. */
+	do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
+}
+
+static void monitor_event_exception(struct pt_regs *regs)
+{
+	if (user_mode(regs))
+		return;
+
+	switch (report_bug(regs->psw.addr - (regs->int_code >> 16), regs)) {
+	case BUG_TRAP_TYPE_NONE:
+		fixup_exception(regs);
+		break;
+	case BUG_TRAP_TYPE_WARN:
+		break;
+	case BUG_TRAP_TYPE_BUG:
+		die(regs, "monitor event");
+		break;
+	}
+}
+
+void kernel_stack_overflow(struct pt_regs *regs)
+{
+	bust_spinlocks(1);
+	printk("Kernel stack overflow.\n");
+	show_regs(regs);
+	bust_spinlocks(0);
+	panic("Corrupt kernel stack, can't continue.");
+}
+NOKPROBE_SYMBOL(kernel_stack_overflow);
+
+static void __init test_monitor_call(void)
+{
+	int val = 1;
+
+	if (!IS_ENABLED(CONFIG_BUG))
+		return;
+	asm volatile(
+		"	mc	0,0\n"
+		"0:	xgr	%0,%0\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "+d" (val));
+	if (!val)
+		panic("Monitor call doesn't work!\n");
+}
+
+void __init trap_init(void)
+{
+	local_mcck_enable();
+	test_monitor_call();
+}
+
+static void (*pgm_check_table[128])(struct pt_regs *regs);
+
+void noinstr __do_pgm_check(struct pt_regs *regs)
+{
+	unsigned int trapnr;
+	irqentry_state_t state;
+
+	regs->int_code = S390_lowcore.pgm_int_code;
+	regs->int_parm_long = S390_lowcore.trans_exc_code;
+
+	state = irqentry_enter(regs);
+
+	if (user_mode(regs)) {
+		update_timer_sys();
+		if (!static_branch_likely(&cpu_has_bear)) {
+			if (regs->last_break < 4096)
+				regs->last_break = 1;
+		}
+		current->thread.last_break = regs->last_break;
+	}
+
+	if (S390_lowcore.pgm_code & 0x0200) {
+		/* transaction abort */
+		current->thread.trap_tdb = S390_lowcore.pgm_tdb;
+	}
+
+	if (S390_lowcore.pgm_code & PGM_INT_CODE_PER) {
+		if (user_mode(regs)) {
+			struct per_event *ev = &current->thread.per_event;
+
+			set_thread_flag(TIF_PER_TRAP);
+			ev->address = S390_lowcore.per_address;
+			ev->cause = S390_lowcore.per_code_combined;
+			ev->paid = S390_lowcore.per_access_id;
+		} else {
+			/* PER event in kernel is kprobes */
+			__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
+			do_per_trap(regs);
+			goto out;
+		}
+	}
+
+	if (!irqs_disabled_flags(regs->psw.mask))
+		trace_hardirqs_on();
+	__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
+
+	trapnr = regs->int_code & PGM_INT_CODE_MASK;
+	if (trapnr)
+		pgm_check_table[trapnr](regs);
+out:
+	local_irq_disable();
+	irqentry_exit(regs, state);
+}
+
+/*
+ * The program check table contains exactly 128 (0x00-0x7f) entries. Each
+ * line defines the function to be called corresponding to the program check
+ * interruption code.
+ */
+static void (*pgm_check_table[128])(struct pt_regs *regs) = {
+	[0x00]		= default_trap_handler,
+	[0x01]		= illegal_op,
+	[0x02]		= privileged_op,
+	[0x03]		= execute_exception,
+	[0x04]		= do_protection_exception,
+	[0x05]		= addressing_exception,
+	[0x06]		= specification_exception,
+	[0x07]		= data_exception,
+	[0x08]		= overflow_exception,
+	[0x09]		= divide_exception,
+	[0x0a]		= overflow_exception,
+	[0x0b]		= divide_exception,
+	[0x0c]		= hfp_overflow_exception,
+	[0x0d]		= hfp_underflow_exception,
+	[0x0e]		= hfp_significance_exception,
+	[0x0f]		= hfp_divide_exception,
+	[0x10]		= do_dat_exception,
+	[0x11]		= do_dat_exception,
+	[0x12]		= translation_specification_exception,
+	[0x13]		= special_op_exception,
+	[0x14]		= default_trap_handler,
+	[0x15]		= operand_exception,
+	[0x16]		= default_trap_handler,
+	[0x17]		= default_trap_handler,
+	[0x18]		= transaction_exception,
+	[0x19]		= default_trap_handler,
+	[0x1a]		= default_trap_handler,
+	[0x1b]		= vector_exception,
+	[0x1c]		= space_switch_exception,
+	[0x1d]		= hfp_sqrt_exception,
+	[0x1e ... 0x37] = default_trap_handler,
+	[0x38]		= do_dat_exception,
+	[0x39]		= do_dat_exception,
+	[0x3a]		= do_dat_exception,
+	[0x3b]		= do_dat_exception,
+	[0x3c]		= default_trap_handler,
+	[0x3d]		= do_secure_storage_access,
+	[0x3e]		= do_non_secure_storage_access,
+	[0x3f]		= do_secure_storage_violation,
+	[0x40]		= monitor_event_exception,
+	[0x41 ... 0x7f] = default_trap_handler,
+};
+
+#define COND_TRAP(x) asm(			\
+	".weak " __stringify(x) "\n\t"		\
+	".set  " __stringify(x) ","		\
+	__stringify(default_trap_handler))
+
+COND_TRAP(do_secure_storage_access);
+COND_TRAP(do_non_secure_storage_access);
+COND_TRAP(do_secure_storage_violation);