1 files changed, 38 insertions, 94 deletions

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 13ebd5ca2070..8af4e0e85736 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -34,6 +34,7 @@
 #include <asm/daifflags.h>
 #include <asm/debug-monitors.h>
 #include <asm/esr.h>
+#include <asm/extable.h>
 #include <asm/insn.h>
 #include <asm/kprobes.h>
 #include <asm/traps.h>
@@ -53,11 +54,6 @@ static const char *handler[]= {
 
 int show_unhandled_signals = 0;
 
-static void dump_backtrace_entry(unsigned long where, const char *loglvl)
-{
-	printk("%s %pS\n", loglvl, (void *)where);
-}
-
 static void dump_kernel_instr(const char *lvl, struct pt_regs *regs)
 {
 	unsigned long addr = instruction_pointer(regs);
@@ -83,66 +79,6 @@ static void dump_kernel_instr(const char *lvl, struct pt_regs *regs)
 	printk("%sCode: %s\n", lvl, str);
 }
 
-void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
-		    const char *loglvl)
-{
-	struct stackframe frame;
-	int skip = 0;
-
-	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
-
-	if (regs) {
-		if (user_mode(regs))
-			return;
-		skip = 1;
-	}
-
-	if (!tsk)
-		tsk = current;
-
-	if (!try_get_task_stack(tsk))
-		return;
-
-	if (tsk == current) {
-		start_backtrace(&frame,
-				(unsigned long)__builtin_frame_address(0),
-				(unsigned long)dump_backtrace);
-	} else {
-		/*
-		 * task blocked in __switch_to
-		 */
-		start_backtrace(&frame,
-				thread_saved_fp(tsk),
-				thread_saved_pc(tsk));
-	}
-
-	printk("%sCall trace:\n", loglvl);
-	do {
-		/* skip until specified stack frame */
-		if (!skip) {
-			dump_backtrace_entry(frame.pc, loglvl);
-		} else if (frame.fp == regs->regs[29]) {
-			skip = 0;
-			/*
-			 * Mostly, this is the case where this function is
-			 * called in panic/abort. As exception handler's
-			 * stack frame does not contain the corresponding pc
-			 * at which an exception has taken place, use regs->pc
-			 * instead.
-			 */
-			dump_backtrace_entry(regs->pc, loglvl);
-		}
-	} while (!unwind_frame(tsk, &frame));
-
-	put_task_stack(tsk);
-}
-
-void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
-{
-	dump_backtrace(NULL, tsk, loglvl);
-	barrier();
-}
-
 #ifdef CONFIG_PREEMPT
 #define S_PREEMPT " PREEMPT"
 #elif defined(CONFIG_PREEMPT_RT)
@@ -200,9 +136,9 @@ void die(const char *str, struct pt_regs *regs, int err)
 	oops_exit();
 
 	if (in_interrupt())
-		panic("Fatal exception in interrupt");
+		panic("%s: Fatal exception in interrupt", str);
 	if (panic_on_oops)
-		panic("Fatal exception");
+		panic("%s: Fatal exception", str);
 
 	raw_spin_unlock_irqrestore(&die_lock, flags);
 
@@ -412,7 +348,7 @@ exit:
 	return fn ? fn(regs, instr) : 1;
 }
 
-void force_signal_inject(int signal, int code, unsigned long address)
+void force_signal_inject(int signal, int code, unsigned long address, unsigned int err)
 {
 	const char *desc;
 	struct pt_regs *regs = current_pt_regs();
@@ -438,7 +374,7 @@ void force_signal_inject(int signal, int code, unsigned long address)
 		signal = SIGKILL;
 	}
 
-	arm64_notify_die(desc, regs, signal, code, (void __user *)address, 0);
+	arm64_notify_die(desc, regs, signal, code, (void __user *)address, err);
 }
 
 /*
@@ -455,7 +391,7 @@ void arm64_notify_segfault(unsigned long addr)
 		code = SEGV_ACCERR;
 	mmap_read_unlock(current->mm);
 
-	force_signal_inject(SIGSEGV, code, addr);
+	force_signal_inject(SIGSEGV, code, addr, 0);
 }
 
 void do_undefinstr(struct pt_regs *regs)
@@ -468,17 +404,28 @@ void do_undefinstr(struct pt_regs *regs)
 		return;
 
 	BUG_ON(!user_mode(regs));
-	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
+	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
 }
 NOKPROBE_SYMBOL(do_undefinstr);
 
 void do_bti(struct pt_regs *regs)
 {
 	BUG_ON(!user_mode(regs));
-	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
+	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
 }
 NOKPROBE_SYMBOL(do_bti);
 
+void do_ptrauth_fault(struct pt_regs *regs, unsigned int esr)
+{
+	/*
+	 * Unexpected FPAC exception or pointer authentication failure in
+	 * the kernel: kill the task before it does any more harm.
+	 */
+	BUG_ON(!user_mode(regs));
+	force_signal_inject(SIGILL, ILL_ILLOPN, regs->pc, esr);
+}
+NOKPROBE_SYMBOL(do_ptrauth_fault);
+
 #define __user_cache_maint(insn, address, res)			\
 	if (address >= user_addr_max()) {			\
 		res = -EFAULT;					\
@@ -528,7 +475,7 @@ static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs)
 		__user_cache_maint("ic ivau", address, ret);
 		break;
 	default:
-		force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
+		force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
 		return;
 	}
 
@@ -581,7 +528,7 @@ static void mrs_handler(unsigned int esr, struct pt_regs *regs)
 	sysreg = esr_sys64_to_sysreg(esr);
 
 	if (do_emulate_mrs(regs, sysreg, rt) != 0)
-		force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
+		force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
 }
 
 static void wfi_handler(unsigned int esr, struct pt_regs *regs)
@@ -775,6 +722,7 @@ static const char *esr_class_str[] = {
 	[ESR_ELx_EC_SYS64]		= "MSR/MRS (AArch64)",
 	[ESR_ELx_EC_SVE]		= "SVE",
 	[ESR_ELx_EC_ERET]		= "ERET/ERETAA/ERETAB",
+	[ESR_ELx_EC_FPAC]		= "FPAC",
 	[ESR_ELx_EC_IMP_DEF]		= "EL3 IMP DEF",
 	[ESR_ELx_EC_IABT_LOW]		= "IABT (lower EL)",
 	[ESR_ELx_EC_IABT_CUR]		= "IABT (current EL)",
@@ -935,26 +883,6 @@ asmlinkage void enter_from_user_mode(void)
 }
 NOKPROBE_SYMBOL(enter_from_user_mode);
 
-void __pte_error(const char *file, int line, unsigned long val)
-{
-	pr_err("%s:%d: bad pte %016lx.\n", file, line, val);
-}
-
-void __pmd_error(const char *file, int line, unsigned long val)
-{
-	pr_err("%s:%d: bad pmd %016lx.\n", file, line, val);
-}
-
-void __pud_error(const char *file, int line, unsigned long val)
-{
-	pr_err("%s:%d: bad pud %016lx.\n", file, line, val);
-}
-
-void __pgd_error(const char *file, int line, unsigned long val)
-{
-	pr_err("%s:%d: bad pgd %016lx.\n", file, line, val);
-}
-
 /* GENERIC_BUG traps */
 
 int is_valid_bugaddr(unsigned long addr)
@@ -994,6 +922,21 @@ static struct break_hook bug_break_hook = {
 	.imm = BUG_BRK_IMM,
 };
 
+static int reserved_fault_handler(struct pt_regs *regs, unsigned int esr)
+{
+	pr_err("%s generated an invalid instruction at %pS!\n",
+		in_bpf_jit(regs) ? "BPF JIT" : "Kernel text patching",
+		(void *)instruction_pointer(regs));
+
+	/* We cannot handle this */
+	return DBG_HOOK_ERROR;
+}
+
+static struct break_hook fault_break_hook = {
+	.fn = reserved_fault_handler,
+	.imm = FAULT_BRK_IMM,
+};
+
 #ifdef CONFIG_KASAN_SW_TAGS
 
 #define KASAN_ESR_RECOVER	0x20
@@ -1059,6 +1002,7 @@ int __init early_brk64(unsigned long addr, unsigned int esr,
 void __init trap_init(void)
 {
 	register_kernel_break_hook(&bug_break_hook);
+	register_kernel_break_hook(&fault_break_hook);
 #ifdef CONFIG_KASAN_SW_TAGS
 	register_kernel_break_hook(&kasan_break_hook);
 #endif