FAILED: patch "[PATCH] lib/ubsan: add type mismatch handler for new GCC/Clang" failed to apply to 4.15-stable tree

PATCH [email protected] 2 participants 3 messages Feb 15, 2018

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Stable branch Library code Ubsan

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[email protected]

author maintainer

2018-02-15 08:14 UTC #0 lore raw

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 <[email protected]>.

thanks,

greg k-h

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

Quoted 1 line

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

From: Andrey Ryabinin <[email protected]>
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/[email protected] open here

Signed-off-by Andrey Ryabinin <[email protected]>

Reported-by Sodagudi Prasad <[email protected]>

Cc <[email protected]> [4.5+]

Signed-off-by Andrew Morton <[email protected]>

Signed-off-by Linus Torvalds <[email protected]>

lib/ubsan.c +38 ~~-10~~

index 1e2328fa002d..50d1d5c25deb 100644
@@ -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

index 88f23557edbe..7e30b26497e0 100644
@@ -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;

Andrey Ryabinin

2018-02-15 09:17 UTC #1 lore raw

Quoted 6 lines · On 02/15/2018 11:14 AM, [email protected] wrote:

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 <[email protected]>.

You can apply it cleanly if you apply b8fe1120b4ba342b4f156d24e952d6e686b20298 ("lib/ubsan.c: s/missaligned/misaligned/") first. That is a simple spelling fix in a function name, which caused this conflict.

Or I can resolve the conflict and send you the backport. What would you prefer?

Quoted 11 lines

thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 42440c1f9911b4b7b8ba3dc4e90c1197bc561211 Mon Sep 17 00:00:00 2001
From: Andrey Ryabinin <[email protected]>
Date: Tue, 6 Feb 2018 15:40:42 -0800
Subject: [PATCH] lib/ubsan: add type mismatch handler for new GCC/Clang

Greg KH

author maintainer

2018-02-15 10:06 UTC #2 lore raw

Quoted 10 lines · Andrey Ryabinin

Quoted 6 lines · On 02/15/2018 11:14 AM, [email protected] wrote:
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 <[email protected]>.

Quoted 4 lines

You can apply it cleanly if you apply b8fe1120b4ba342b4f156d24e952d6e686b20298 ("lib/ubsan.c: s/missaligned/misaligned/") first. That is a simple spelling fix in a function name, which caused this conflict.
Or I can resolve the conflict and send you the backport. What would you prefer?

I've now queued up both patches, thanks for the hint.

greg k-h