The patch below does not apply to the 4.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 42440c1f9911b4b7b8ba3dc4e90c1197bc561211 Mon Sep 17 00:00:00 2001

From: Andrey Ryabinin aryabinin@virtuozzo.com Date: Tue, 6 Feb 2018 15:40:42 -0800 Subject: [PATCH] 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 1e2328fa002d..50d1d5c25deb 100644 --- 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 88f23557edbe..7e30b26497e0 100644 --- 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;