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Diffstat (limited to 'arch/arm64/kernel/traps.c')
-rw-r--r--arch/arm64/kernel/traps.c94
1 files changed, 80 insertions, 14 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 566bc4c35..f93aae5e4 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);
}