Commit 42440c1f authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by Linus Torvalds
Browse files

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: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: default avatarSodagudi Prasad <psodagud@codeaurora.org>
Cc: <stable@vger.kernel.org>	[4.5+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b8fe1120

lib/ubsan.c

+38 −10
Original line number Diff line number Diff line
@@ -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;

lib/ubsan.h

+14 −0
Original line number Diff line number Diff line
@@ -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;

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