4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrey Ryabinin <aryabi...@virtuozzo.com>

commit 42440c1f9911b4b7b8ba3dc4e90c1197bc561211 upstream.

UBSAN=y fails to build with new GCC/clang:

    arch/x86/kernel/head64.o: In function `sanitize_boot_params':
    arch/x86/include/asm/bootparam_utils.h:37: undefined reference to 
`__ubsan_handle_type_mismatch_v1'

because Clang and GCC 8 slightly changed ABI for 'type mismatch' errors.
Compiler now uses new __ubsan_handle_type_mismatch_v1() function with
slightly modified 'struct type_mismatch_data'.

Let's add new 'struct type_mismatch_data_common' which is independent from
compiler's layout of 'struct type_mismatch_data'.  And make
__ubsan_handle_type_mismatch[_v1]() functions transform compiler-dependent
type mismatch data to our internal representation.  This way, we can
support both old and new compilers with minimal amount of change.

Link: http://lkml.kernel.org/r/20180119152853.16806-1-aryabi...@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com>
Reported-by: Sodagudi Prasad <psoda...@codeaurora.org>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 lib/ubsan.c |   48 ++++++++++++++++++++++++++++++++++++++----------
 lib/ubsan.h |   14 ++++++++++++++
 2 files changed, 52 insertions(+), 10 deletions(-)

--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -265,14 +265,14 @@ void __ubsan_handle_divrem_overflow(stru
 }
 EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);
 
-static void handle_null_ptr_deref(struct type_mismatch_data *data)
+static void handle_null_ptr_deref(struct type_mismatch_data_common *data)
 {
        unsigned long flags;
 
-       if (suppress_report(&data->location))
+       if (suppress_report(data->location))
                return;
 
-       ubsan_prologue(&data->location, &flags);
+       ubsan_prologue(data->location, &flags);
 
        pr_err("%s null pointer of type %s\n",
                type_check_kinds[data->type_check_kind],
@@ -281,15 +281,15 @@ static void handle_null_ptr_deref(struct
        ubsan_epilogue(&flags);
 }
 
-static void handle_misaligned_access(struct type_mismatch_data *data,
+static void handle_misaligned_access(struct type_mismatch_data_common *data,
                                unsigned long ptr)
 {
        unsigned long flags;
 
-       if (suppress_report(&data->location))
+       if (suppress_report(data->location))
                return;
 
-       ubsan_prologue(&data->location, &flags);
+       ubsan_prologue(data->location, &flags);
 
        pr_err("%s misaligned address %p for type %s\n",
                type_check_kinds[data->type_check_kind],
@@ -299,15 +299,15 @@ static void handle_misaligned_access(str
        ubsan_epilogue(&flags);
 }
 
-static void handle_object_size_mismatch(struct type_mismatch_data *data,
+static void handle_object_size_mismatch(struct type_mismatch_data_common *data,
                                        unsigned long ptr)
 {
        unsigned long flags;
 
-       if (suppress_report(&data->location))
+       if (suppress_report(data->location))
                return;
 
-       ubsan_prologue(&data->location, &flags);
+       ubsan_prologue(data->location, &flags);
        pr_err("%s address %p with insufficient space\n",
                type_check_kinds[data->type_check_kind],
                (void *) ptr);
@@ -315,7 +315,7 @@ static void handle_object_size_mismatch(
        ubsan_epilogue(&flags);
 }
 
-void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
+static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data,
                                unsigned long ptr)
 {
 
@@ -326,8 +326,36 @@ void __ubsan_handle_type_mismatch(struct
        else
                handle_object_size_mismatch(data, ptr);
 }
+
+void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
+                               unsigned long ptr)
+{
+       struct type_mismatch_data_common common_data = {
+               .location = &data->location,
+               .type = data->type,
+               .alignment = data->alignment,
+               .type_check_kind = data->type_check_kind
+       };
+
+       ubsan_type_mismatch_common(&common_data, ptr);
+}
 EXPORT_SYMBOL(__ubsan_handle_type_mismatch);
 
+void __ubsan_handle_type_mismatch_v1(struct type_mismatch_data_v1 *data,
+                               unsigned long ptr)
+{
+
+       struct type_mismatch_data_common common_data = {
+               .location = &data->location,
+               .type = data->type,
+               .alignment = 1UL << data->log_alignment,
+               .type_check_kind = data->type_check_kind
+       };
+
+       ubsan_type_mismatch_common(&common_data, ptr);
+}
+EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);
+
 void __ubsan_handle_nonnull_return(struct nonnull_return_data *data)
 {
        unsigned long flags;
--- a/lib/ubsan.h
+++ b/lib/ubsan.h
@@ -36,6 +36,20 @@ struct type_mismatch_data {
        unsigned char type_check_kind;
 };
 
+struct type_mismatch_data_v1 {
+       struct source_location location;
+       struct type_descriptor *type;
+       unsigned char log_alignment;
+       unsigned char type_check_kind;
+};
+
+struct type_mismatch_data_common {
+       struct source_location *location;
+       struct type_descriptor *type;
+       unsigned long alignment;
+       unsigned char type_check_kind;
+};
+
 struct nonnull_arg_data {
        struct source_location location;
        struct source_location attr_location;


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