diff options
Diffstat (limited to 'arch/arm64/kernel/traps.c')
| -rw-r--r-- | arch/arm64/kernel/traps.c | 94 |
1 files changed, 80 insertions, 14 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 566bc4c35040..f93aae5e4307 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> @@ -52,11 +55,12 @@ int show_unhandled_signals = 1; * Dump out the contents of some memory nicely... */ static void dump_mem(const char *lvl, const char *str, unsigned long bottom, - unsigned long top) + unsigned long top, bool compat) { unsigned long first; mm_segment_t fs; int i; + unsigned int width = compat ? 4 : 8; /* * We need to switch to kernel mode so that we can use __get_user @@ -75,13 +79,22 @@ static void dump_mem(const char *lvl, const char *str, unsigned long bottom, memset(str, ' ', sizeof(str)); str[sizeof(str) - 1] = '\0'; - for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { + for (p = first, i = 0; i < (32 / width) + && p < top; i++, p += width) { if (p >= bottom && p < top) { - unsigned int val; - if (__get_user(val, (unsigned int *)p) == 0) - sprintf(str + i * 9, " %08x", val); - else - sprintf(str + i * 9, " ????????"); + unsigned long val; + + if (width == 8) { + if (__get_user(val, (unsigned long *)p) == 0) + sprintf(str + i * 17, " %016lx", val); + else + sprintf(str + i * 17, " ????????????????"); + } else { + if (__get_user(val, (unsigned int *)p) == 0) + sprintf(str + i * 9, " %08lx", val); + else + sprintf(str + i * 9, " ????????"); + } } } printk("%s%04lx:%s\n", lvl, first & 0xffff, str); @@ -95,7 +108,7 @@ static void dump_backtrace_entry(unsigned long where, unsigned long stack) print_ip_sym(where); if (in_exception_text(where)) dump_mem("", "Exception stack", stack, - stack + sizeof(struct pt_regs)); + stack + sizeof(struct pt_regs), false); } static void dump_instr(const char *lvl, struct pt_regs *regs) @@ -179,11 +192,7 @@ void show_stack(struct task_struct *tsk, unsigned long *sp) #else #define S_PREEMPT "" #endif -#ifdef CONFIG_SMP #define S_SMP " SMP" -#else -#define S_SMP "" -#endif static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) @@ -207,7 +216,8 @@ static int __die(const char *str, int err, struct thread_info *thread, if (!user_mode(regs) || in_interrupt()) { dump_mem(KERN_EMERG, "Stack: ", regs->sp, - THREAD_SIZE + (unsigned long)task_stack_page(tsk)); + THREAD_SIZE + (unsigned long)task_stack_page(tsk), + compat_user_mode(regs)); dump_backtrace(regs, tsk); dump_instr(KERN_EMERG, regs); } @@ -459,7 +469,63 @@ 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: + /* Ideally, report_bug() should backtrace for us... but no. */ + dump_backtrace(regs, NULL); + 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); } |