diff options
| -rw-r--r-- | arch/arm64/Kconfig | 8 | ||||
| -rw-r--r-- | arch/arm64/include/asm/bug.h | 64 | ||||
| -rw-r--r-- | arch/arm64/include/asm/debug-monitors.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/traps.c | 59 | ||||
| -rw-r--r-- | arch/arm64/mm/fault.c | 12 |
5 files changed, 142 insertions, 3 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index c2bd79a02a6c..5372e1e0c11c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -113,6 +113,14 @@ config TRACE_IRQFLAGS_SUPPORT config RWSEM_XCHGADD_ALGORITHM def_bool y +config GENERIC_BUG + def_bool y + depends on BUG + +config GENERIC_BUG_RELATIVE_POINTERS + def_bool y + depends on GENERIC_BUG + config GENERIC_HWEIGHT def_bool y diff --git a/arch/arm64/include/asm/bug.h b/arch/arm64/include/asm/bug.h new file mode 100644 index 000000000000..4a748ce9ba1a --- /dev/null +++ b/arch/arm64/include/asm/bug.h @@ -0,0 +1,64 @@ +/* + * Copyright (C) 2015 ARM Limited + * Author: Dave Martin <Dave.Martin@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef _ARCH_ARM64_ASM_BUG_H +#define _ARCH_ARM64_ASM_BUG_H + +#include <asm/debug-monitors.h> + +#ifdef CONFIG_GENERIC_BUG +#define HAVE_ARCH_BUG + +#ifdef CONFIG_DEBUG_BUGVERBOSE +#define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line) +#define __BUGVERBOSE_LOCATION(file, line) \ + ".pushsection .rodata.str,\"aMS\",@progbits,1\n" \ + "2: .string \"" file "\"\n\t" \ + ".popsection\n\t" \ + \ + ".long 2b - 0b\n\t" \ + ".short " #line "\n\t" +#else +#define _BUGVERBOSE_LOCATION(file, line) +#endif + +#define _BUG_FLAGS(flags) __BUG_FLAGS(flags) + +#define __BUG_FLAGS(flags) asm volatile ( \ + ".pushsection __bug_table,\"a\"\n\t" \ + ".align 2\n\t" \ + "0: .long 1f - 0b\n\t" \ +_BUGVERBOSE_LOCATION(__FILE__, __LINE__) \ + ".short " #flags "\n\t" \ + ".popsection\n" \ + \ + "1: brk %[imm]" \ + :: [imm] "i" (BUG_BRK_IMM) \ +) + +#define BUG() do { \ + _BUG_FLAGS(0); \ + unreachable(); \ +} while (0) + +#define __WARN_TAINT(taint) _BUG_FLAGS(BUGFLAG_TAINT(taint)) + +#endif /* ! CONFIG_GENERIC_BUG */ + +#include <asm-generic/bug.h> + +#endif /* ! _ARCH_ARM64_ASM_BUG_H */ diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h index 777c36a1f645..e3f2bad788c9 100644 --- a/arch/arm64/include/asm/debug-monitors.h +++ b/arch/arm64/include/asm/debug-monitors.h @@ -52,10 +52,12 @@ * 0x100: for triggering a fault on purpose (reserved) * 0x400: for dynamic BRK instruction * 0x401: for compile time BRK instruction + * 0x800: kernel-mode BUG() and WARN() traps */ #define FAULT_BRK_IMM 0x100 #define KGDB_DYN_DBG_BRK_IMM 0x400 #define KGDB_COMPILED_DBG_BRK_IMM 0x401 +#define BUG_BRK_IMM 0x800 /* * BRK instruction encoding diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 1ea920cbd66d..824ba5ac6361 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -17,6 +17,7 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/bug.h> #include <linux/signal.h> #include <linux/personality.h> #include <linux/kallsyms.h> @@ -32,8 +33,10 @@ #include <linux/syscalls.h> #include <asm/atomic.h> +#include <asm/bug.h> #include <asm/debug-monitors.h> #include <asm/esr.h> +#include <asm/insn.h> #include <asm/traps.h> #include <asm/stacktrace.h> #include <asm/exception.h> @@ -466,7 +469,61 @@ void __pgd_error(const char *file, int line, unsigned long val) pr_crit("%s:%d: bad pgd %016lx.\n", file, line, val); } +/* GENERIC_BUG traps */ + +int is_valid_bugaddr(unsigned long addr) +{ + /* + * bug_handler() only called for BRK #BUG_BRK_IMM. + * So the answer is trivial -- any spurious instances with no + * bug table entry will be rejected by report_bug() and passed + * back to the debug-monitors code and handled as a fatal + * unexpected debug exception. + */ + return 1; +} + +static int bug_handler(struct pt_regs *regs, unsigned int esr) +{ + if (user_mode(regs)) + return DBG_HOOK_ERROR; + + switch (report_bug(regs->pc, regs)) { + case BUG_TRAP_TYPE_BUG: + die("Oops - BUG", regs, 0); + break; + + case BUG_TRAP_TYPE_WARN: + break; + + default: + /* unknown/unrecognised bug trap type */ + return DBG_HOOK_ERROR; + } + + /* If thread survives, skip over the BUG instruction and continue: */ + regs->pc += AARCH64_INSN_SIZE; /* skip BRK and resume */ + return DBG_HOOK_HANDLED; +} + +static struct break_hook bug_break_hook = { + .esr_val = 0xf2000000 | BUG_BRK_IMM, + .esr_mask = 0xffffffff, + .fn = bug_handler, +}; + +/* + * Initial handler for AArch64 BRK exceptions + * This handler only used until debug_traps_init(). + */ +int __init early_brk64(unsigned long addr, unsigned int esr, + struct pt_regs *regs) +{ + return bug_handler(regs, esr) != DBG_HOOK_HANDLED; +} + +/* This registration must happen early, before debug_traps_init(). */ void __init trap_init(void) { - return; + register_break_hook(&bug_break_hook); } diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index ce591211434e..aba9ead1384c 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -501,14 +501,22 @@ asmlinkage void __exception do_sp_pc_abort(unsigned long addr, arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr); } -static struct fault_info debug_fault_info[] = { +int __init early_brk64(unsigned long addr, unsigned int esr, + struct pt_regs *regs); + +/* + * __refdata because early_brk64 is __init, but the reference to it is + * clobbered at arch_initcall time. + * See traps.c and debug-monitors.c:debug_traps_init(). + */ +static struct fault_info __refdata debug_fault_info[] = { { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, { do_bad, SIGBUS, 0, "unknown 3" }, { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, { do_bad, SIGTRAP, 0, "aarch32 vector catch" }, - { do_bad, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, + { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, { do_bad, SIGBUS, 0, "unknown 7" }, }; |