lib/ubsan: add type mismatch handler for new GCC/Clang

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-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Sodagudi Prasad <psodagud@codeaurora.org>
Cc: <stable@vger.kernel.org>	[4.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/ubsan.c b/lib/ubsan.c
index 1e2328fa002ddeb1edccb098a373fc42bdb59b30..50d1d5c25deb89501d967e3aed1d900870fd8299 100644 (file)
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -265,14 +265,14 @@ void __ubsan_handle_divrem_overflow(struct overflow_data *data,
 }
 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 type_mismatch_data *data)
        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(struct type_mismatch_data *data,
        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(struct type_mismatch_data *data,
        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 type_mismatch_data *data,
        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;

diff --git a/lib/ubsan.h b/lib/ubsan.h
index 88f23557edbe16d5a60d691591d4e1981437f7d7..7e30b26497e0cd0e2d7c055222349eac5d228a84 100644 (file)
--- a/lib/ubsan.h
+++ b/lib/ubsan.h
@@ -37,6 +37,20 @@ 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;