diff options
Diffstat (limited to 'arch/arm64/kernel/traps.c')
| -rw-r--r-- | arch/arm64/kernel/traps.c | 59 |
1 files changed, 58 insertions, 1 deletions
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); } |