Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - a lot more of MM, quite a bit more yet to come: (memcg, pagemap,
   vmalloc, pagealloc, migration, thp, ksm, madvise, virtio,
   userfaultfd, memory-hotplug, shmem, rmap, zswap, zsmalloc, cleanups)

 - various other subsystems (procfs, misc, MAINTAINERS, bitops, lib,
   checkpatch, epoll, binfmt, kallsyms, reiserfs, kmod, gcov, kconfig,
   ubsan, fault-injection, ipc)

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (158 commits)
  ipc/shm.c: make compat_ksys_shmctl() static
  ipc/mqueue.c: fix a brace coding style issue
  lib/Kconfig.debug: fix a typo "capabilitiy" -> "capability"
  ubsan: include bug type in report header
  kasan: unset panic_on_warn before calling panic()
  ubsan: check panic_on_warn
  drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks
  ubsan: split "bounds" checker from other options
  ubsan: add trap instrumentation option
  init/Kconfig: clean up ANON_INODES and old IO schedulers options
  kernel/gcov/fs.c: replace zero-length array with flexible-array member
  gcov: gcc_3_4: replace zero-length array with flexible-array member
  gcov: gcc_4_7: replace zero-length array with flexible-array member
  kernel/kmod.c: fix a typo "assuems" -> "assumes"
  reiserfs: clean up several indentation issues
  kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()
  samples/hw_breakpoint: drop use of kallsyms_lookup_name()
  samples/hw_breakpoint: drop HW_BREAKPOINT_R when reporting writes
  fs/binfmt_elf.c: don't free interpreter's ELF pheaders on common path
  fs/binfmt_elf.c: allocate less for static executable
  ...

1 files changed, 26 insertions, 21 deletions

diff --git a/lib/ubsan.c b/lib/ubsan.c
index 7b9b58aee72c..f8c0ccf35f29 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -45,13 +45,6 @@ static bool was_reported(struct source_location *location)
 	return test_and_set_bit(REPORTED_BIT, &location->reported);
 }
 
-static void print_source_location(const char *prefix,
-				struct source_location *loc)
-{
-	pr_err("%s %s:%d:%d\n", prefix, loc->file_name,
-		loc->line & LINE_MASK, loc->column & COLUMN_MASK);
-}
-
 static bool suppress_report(struct source_location *loc)
 {
 	return current->in_ubsan || was_reported(loc);
@@ -140,13 +133,14 @@ static void val_to_string(char *str, size_t size, struct type_descriptor *type,
 	}
 }
 
-static void ubsan_prologue(struct source_location *location)
+static void ubsan_prologue(struct source_location *loc, const char *reason)
 {
 	current->in_ubsan++;
 
 	pr_err("========================================"
 		"========================================\n");
-	print_source_location("UBSAN: Undefined behaviour in", location);
+	pr_err("UBSAN: %s in %s:%d:%d\n", reason, loc->file_name,
+		loc->line & LINE_MASK, loc->column & COLUMN_MASK);
 }
 
 static void ubsan_epilogue(void)
@@ -156,6 +150,17 @@ static void ubsan_epilogue(void)
 		"========================================\n");
 
 	current->in_ubsan--;
+
+	if (panic_on_warn) {
+		/*
+		 * This thread may hit another WARN() in the panic path.
+		 * Resetting this prevents additional WARN() from panicking the
+		 * system on this thread.  Other threads are blocked by the
+		 * panic_mutex in panic().
+		 */
+		panic_on_warn = 0;
+		panic("panic_on_warn set ...\n");
+	}
 }
 
 static void handle_overflow(struct overflow_data *data, void *lhs,
@@ -169,12 +174,12 @@ static void handle_overflow(struct overflow_data *data, void *lhs,
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location);
+	ubsan_prologue(&data->location, type_is_signed(type) ?
+			"signed-integer-overflow" :
+			"unsigned-integer-overflow");
 
 	val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
 	val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
-	pr_err("%s integer overflow:\n",
-		type_is_signed(type) ? "signed" : "unsigned");
 	pr_err("%s %c %s cannot be represented in type %s\n",
 		lhs_val_str,
 		op,
@@ -214,7 +219,7 @@ void __ubsan_handle_negate_overflow(struct overflow_data *data,
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location);
+	ubsan_prologue(&data->location, "negation-overflow");
 
 	val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
 
@@ -234,7 +239,7 @@ void __ubsan_handle_divrem_overflow(struct overflow_data *data,
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location);
+	ubsan_prologue(&data->location, "division-overflow");
 
 	val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
 
@@ -253,7 +258,7 @@ static void handle_null_ptr_deref(struct type_mismatch_data_common *data)
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location);
+	ubsan_prologue(data->location, "null-ptr-deref");
 
 	pr_err("%s null pointer of type %s\n",
 		type_check_kinds[data->type_check_kind],
@@ -268,7 +273,7 @@ static void handle_misaligned_access(struct type_mismatch_data_common *data,
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location);
+	ubsan_prologue(data->location, "misaligned-access");
 
 	pr_err("%s misaligned address %p for type %s\n",
 		type_check_kinds[data->type_check_kind],
@@ -284,7 +289,7 @@ static void handle_object_size_mismatch(struct type_mismatch_data_common *data,
 	if (suppress_report(data->location))
 		return;
 
-	ubsan_prologue(data->location);
+	ubsan_prologue(data->location, "object-size-mismatch");
 	pr_err("%s address %p with insufficient space\n",
 		type_check_kinds[data->type_check_kind],
 		(void *) ptr);
@@ -343,7 +348,7 @@ void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data, void *index)
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location);
+	ubsan_prologue(&data->location, "array-index-out-of-bounds");
 
 	val_to_string(index_str, sizeof(index_str), data->index_type, index);
 	pr_err("index %s is out of range for type %s\n", index_str,
@@ -364,7 +369,7 @@ void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
 	if (suppress_report(&data->location))
 		goto out;
 
-	ubsan_prologue(&data->location);
+	ubsan_prologue(&data->location, "shift-out-of-bounds");
 
 	val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
 	val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
@@ -396,7 +401,7 @@ EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
 
 void __ubsan_handle_builtin_unreachable(struct unreachable_data *data)
 {
-	ubsan_prologue(&data->location);
+	ubsan_prologue(&data->location, "unreachable");
 	pr_err("calling __builtin_unreachable()\n");
 	ubsan_epilogue();
 	panic("can't return from __builtin_unreachable()");
@@ -411,7 +416,7 @@ void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
 	if (suppress_report(&data->location))
 		return;
 
-	ubsan_prologue(&data->location);
+	ubsan_prologue(&data->location, "invalid-load");
 
 	val_to_string(val_str, sizeof(val_str), data->type, val);