Re: [PATCHv2 2/7, GCC, ARM, V8M] Handling ARMv8-M Security Extension's cmse_nonsecure_entry attribute

2016-10-27 Thread Kyrill Tkachov 


On 27/10/16 10:54, Andre Vieira (lists) wrote:

On 26/10/16 17:28, Kyrill Tkachov wrote:

On 26/10/16 17:28, Andre Vieira (lists) wrote:

On 26/10/16 10:33, Kyrill Tkachov wrote:

+static tree
+arm_handle_cmse_nonsecure_entry (tree *node, tree name,
+ tree /* args */,
+ int /* flags */,
+ bool *no_add_attrs)
+{
+  tree fndecl;
+
+  if (!use_cmse)
+{
+  *no_add_attrs = true;
+  return NULL_TREE;
+}

Do you also want to warn the user here that the attribute will be
ignored?
This looks ok to me otherwise.


Can easily do and might be more user friendly. How about
" attribute ignored without -mcmse option."

Yes, that's fine (without the full stop at the end)
Kyrill


Cheers,
Andre


Hi,

Reworked comments. No change to ChangeLogs.


Ok.
Thanks,
Kyrill


Cheers,
Andre

Re: [PATCHv2 2/7, GCC, ARM, V8M] Handling ARMv8-M Security Extension's cmse_nonsecure_entry attribute

2016-10-27 Thread Andre Vieira (lists) 
On 26/10/16 17:28, Kyrill Tkachov wrote:
> 
> On 26/10/16 17:28, Andre Vieira (lists) wrote:
>> On 26/10/16 10:33, Kyrill Tkachov wrote:
>>> +static tree
>>> +arm_handle_cmse_nonsecure_entry (tree *node, tree name,
>>> + tree /* args */,
>>> + int /* flags */,
>>> + bool *no_add_attrs)
>>> +{
>>> +  tree fndecl;
>>> +
>>> +  if (!use_cmse)
>>> +{
>>> +  *no_add_attrs = true;
>>> +  return NULL_TREE;
>>> +}
>>>
>>> Do you also want to warn the user here that the attribute will be
>>> ignored?
>>> This looks ok to me otherwise.
>>>
>> Can easily do and might be more user friendly. How about
>> " attribute ignored without -mcmse option."
> 
> Yes, that's fine (without the full stop at the end)
> Kyrill
> 
>> Cheers,
>> Andre
>>
> 

Hi,

Reworked comments. No change to ChangeLogs.

Cheers,
Andre
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 
a370dccdaa9fa4c980c1df11cb95a65cad16ac85..44d1ac45b03dec210e6986f103bf8588119a8aa8
 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -1386,6 +1386,7 @@ enum reg_class
 #define ARM_FT_VOLATILE(1 << 4) /* Does not return.  */
 #define ARM_FT_NESTED  (1 << 5) /* Embedded inside another func.  */
 #define ARM_FT_STACKALIGN  (1 << 6) /* Called with misaligned stack.  */
+#define ARM_FT_CMSE_ENTRY  (1 << 7) /* ARMv8-M non-secure entry function.  
*/
 
 /* Some macros to test these flags.  */
 #define ARM_FUNC_TYPE(t)   (t & ARM_FT_TYPE_MASK)
@@ -1394,6 +1395,7 @@ enum reg_class
 #define IS_NAKED(t)(t & ARM_FT_NAKED)
 #define IS_NESTED(t)   (t & ARM_FT_NESTED)
 #define IS_STACKALIGN(t)   (t & ARM_FT_STACKALIGN)
+#define IS_CMSE_ENTRY(t)   (t & ARM_FT_CMSE_ENTRY)
 
 
 /* Structure used to hold the function stack frame layout.  Offsets are
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 
44677c1bccad42c5ad603ea0951d62abcbd6f05d..40edd3c7fb9567fadfddc36be777fbf53cbb8e9f
 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -135,6 +135,7 @@ static tree arm_handle_isr_attribute (tree *, tree, tree, 
int, bool *);
 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
 static tree arm_handle_notshared_attribute (tree *, tree, tree, int, bool *);
 #endif
+static tree arm_handle_cmse_nonsecure_entry (tree *, tree, tree, int, bool *);
 static void arm_output_function_epilogue (FILE *, HOST_WIDE_INT);
 static void arm_output_function_prologue (FILE *, HOST_WIDE_INT);
 static int arm_comp_type_attributes (const_tree, const_tree);
@@ -347,6 +348,9 @@ static const struct attribute_spec arm_attribute_table[] =
   { "notshared",0, 0, false, true, false, arm_handle_notshared_attribute,
 false },
 #endif
+  /* ARMv8-M Security Extensions support.  */
+  { "cmse_nonsecure_entry", 0, 0, true, false, false,
+arm_handle_cmse_nonsecure_entry, false },
   { NULL,   0, 0, false, false, false, NULL, false }
 };
 
@@ -3662,6 +3666,9 @@ arm_compute_func_type (void)
   else
 type |= arm_isr_value (TREE_VALUE (a));
 
+  if (lookup_attribute ("cmse_nonsecure_entry", attr))
+type |= ARM_FT_CMSE_ENTRY;
+
   return type;
 }
 
@@ -6661,6 +6668,113 @@ arm_handle_notshared_attribute (tree *node,
 }
 #endif
 
+/* This function returns true if a function with declaration FNDECL and type
+   FNTYPE uses the stack to pass arguments or return variables and false
+   otherwise.  This is used for functions with the attributes
+   'cmse_nonsecure_call' or 'cmse_nonsecure_entry' and this function will issue
+   diagnostic messages if the stack is used.  NAME is the name of the attribute
+   used.  */
+
+static bool
+cmse_func_args_or_return_in_stack (tree fndecl, tree name, tree fntype)
+{
+  function_args_iterator args_iter;
+  CUMULATIVE_ARGS args_so_far_v;
+  cumulative_args_t args_so_far;
+  bool first_param = true;
+  tree arg_type, prev_arg_type = NULL_TREE, ret_type;
+
+  /* Error out if any argument is passed on the stack.  */
+  arm_init_cumulative_args (_so_far_v, fntype, NULL_RTX, fndecl);
+  args_so_far = pack_cumulative_args (_so_far_v);
+  FOREACH_FUNCTION_ARGS (fntype, arg_type, args_iter)
+{
+  rtx arg_rtx;
+  machine_mode arg_mode = TYPE_MODE (arg_type);
+
+  prev_arg_type = arg_type;
+  if (VOID_TYPE_P (arg_type))
+   continue;
+
+  if (!first_param)
+   arm_function_arg_advance (args_so_far, arg_mode, arg_type, true);
+  arg_rtx = arm_function_arg (args_so_far, arg_mode, arg_type, true);
+  if (!arg_rtx
+ || arm_arg_partial_bytes (args_so_far, arg_mode, arg_type, true))
+   {
+ error ("%qE attribute not available to functions with arguments "
+"passed on the stack", name);
+ return true;
+   }
+  first_param = false;
+}
+
+  /* Error out for variadic functions since we cannot control how many
+ arguments will be passed and thus stack could be used.  stdarg_p () is not
+ used for the checking to avoid

Re: [PATCHv2 2/7, GCC, ARM, V8M] Handling ARMv8-M Security Extension's cmse_nonsecure_entry attribute

2016-10-26 Thread Kyrill Tkachov 


On 26/10/16 17:28, Andre Vieira (lists) wrote:

On 26/10/16 10:33, Kyrill Tkachov wrote:

+static tree
+arm_handle_cmse_nonsecure_entry (tree *node, tree name,
+ tree /* args */,
+ int /* flags */,
+ bool *no_add_attrs)
+{
+  tree fndecl;
+
+  if (!use_cmse)
+{
+  *no_add_attrs = true;
+  return NULL_TREE;
+}

Do you also want to warn the user here that the attribute will be ignored?
This looks ok to me otherwise.


Can easily do and might be more user friendly. How about
" attribute ignored without -mcmse option."


Yes, that's fine (without the full stop at the end)
Kyrill


Cheers,
Andre

Re: [PATCHv2 2/7, GCC, ARM, V8M] Handling ARMv8-M Security Extension's cmse_nonsecure_entry attribute

2016-10-26 Thread Andre Vieira (lists) 
On 26/10/16 10:33, Kyrill Tkachov wrote:
> 
> +static tree
> +arm_handle_cmse_nonsecure_entry (tree *node, tree name,
> + tree /* args */,
> + int /* flags */,
> + bool *no_add_attrs)
> +{
> +  tree fndecl;
> +
> +  if (!use_cmse)
> +{
> +  *no_add_attrs = true;
> +  return NULL_TREE;
> +}
> 
> Do you also want to warn the user here that the attribute will be ignored?
> This looks ok to me otherwise.
> 

Can easily do and might be more user friendly. How about
" attribute ignored without -mcmse option."

Cheers,
Andre

Re: [PATCHv2 2/7, GCC, ARM, V8M] Handling ARMv8-M Security Extension's cmse_nonsecure_entry attribute

2016-10-26 Thread Kyrill Tkachov 

Hi Andre,

On 25/10/16 17:28, Andre Vieira (lists) wrote:

On 24/08/16 12:00, Andre Vieira (lists) wrote:

On 25/07/16 14:21, Andre Vieira (lists) wrote:

This patch adds support for the ARMv8-M Security Extensions
'cmse_nonsecure_entry' attribute. In this patch we implement the
attribute handling and diagnosis around the attribute. See Section 5.4
of ARM®v8-M Security Extensions
(http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/index.html).

*** gcc/ChangeLog ***
2016-07-25  Andre Vieira
 Thomas Preud'homme  

 * config/arm/arm.c (arm_handle_cmse_nonsecure_entry): New.
 (arm_attribute_table): Added cmse_nonsecure_entry
 (arm_compute_func_type): Handle cmse_nonsecure_entry.
 (cmse_func_args_or_return_in_stack): New.
 (arm_handle_cmse_nonsecure_entry): New.
 * config/arm/arm.h (ARM_FT_CMSE_ENTRY): New macro define.
 (IS_CMSE_ENTRY): Likewise.

*** gcc/testsuite/ChangeLog ***
2016-07-25  Andre Vieira
 Thomas Preud'homme  

 * gcc.target/arm/cmse/cmse-3.c: New.


Added more documentation as requested.



This patch adds support for the ARMv8-M Security Extensions
'cmse_nonsecure_entry' attribute. In this patch we implement the
attribute handling and diagnosis around the attribute. See Section 5.4
of ARM®v8-M Security Extensions
(http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/index.html).

*** gcc/ChangeLog ***
2016-07-xx  Andre Vieira
 Thomas Preud'homme  

 * config/arm/arm.c (arm_handle_cmse_nonsecure_entry): New.
 (arm_attribute_table): Added cmse_nonsecure_entry
 (arm_compute_func_type): Handle cmse_nonsecure_entry.
 (cmse_func_args_or_return_in_stack): New.
 (arm_handle_cmse_nonsecure_entry): New.
 * config/arm/arm.h (ARM_FT_CMSE_ENTRY): New macro define.
 (IS_CMSE_ENTRY): Likewise.
 * doc/extend.texi (ARM ARMv8-M Security Extensions): New attribute.

*** gcc/testsuite/ChangeLog ***
2016-07-xx  Andre Vieira
 Thomas Preud'homme  

 * gcc.target/arm/cmse/cmse-3.c: New.


Hi,

Rebased previous patch on top of trunk as requested. No changes to
ChangeLog.

Cheers,
Andre



@@ -6661,6 +6668,110 @@ arm_handle_notshared_attribute (tree *node,
 }
 #endif

+/* This function returns true if a function with declaration FNDECL, name
+   NAME and type FNTYPE uses the stack to pass arguments or return variables
+   and false otherwise.  This is used for functions with the attributes
+   'cmse_nonsecure_call' or 'cmse_nonsecure_entry' and this function will issue
+   diagnostic messages if the stack is used.  */
+

I think NAME is the name of the attribute, not the function. The comment here is
misleading, otherwise the error message in this function doesn't make sense.
Please fix the description.

+static bool
+cmse_func_args_or_return_in_stack (tree fndecl, tree name, tree fntype)
+{
+  function_args_iterator args_iter;
+  CUMULATIVE_ARGS args_so_far_v;
+  cumulative_args_t args_so_far;
+  bool first_param = true;
+  tree arg_type, prev_arg_type = NULL_TREE, ret_type;
+
+  /* Error out if any argument is passed on the stack.  */
+  arm_init_cumulative_args (_so_far_v, fntype, NULL_RTX, fndecl);
+  args_so_far = pack_cumulative_args (_so_far_v);
+  FOREACH_FUNCTION_ARGS (fntype, arg_type, args_iter)
+{
+  rtx arg_rtx;
+  machine_mode arg_mode = TYPE_MODE (arg_type);
+
+  prev_arg_type = arg_type;
+  if (VOID_TYPE_P (arg_type))
+continue;
+
+  if (!first_param)
+arm_function_arg_advance (args_so_far, arg_mode, arg_type, true);
+  arg_rtx = arm_function_arg (args_so_far, arg_mode, arg_type, true);
+  if (!arg_rtx
+  || arm_arg_partial_bytes (args_so_far, arg_mode, arg_type, true))
+{
+  error ("%qE attribute not available to functions with arguments "
+ "passed on the stack", name);
+  return true;
+}
+  first_param = false;
+}
+
+  /* Error out for variadic functions since we cannot control how many
+ arguments will be passed and thus stack could be used. stdarg_p () is not
+ used for the checking to avoid browsing arguments twice.  */
+  if (prev_arg_type != NULL_TREE && !VOID_TYPE_P (prev_arg_type))
+{
+  error ("%qE attribute not available to functions with variable number "
+ "of arguments", name);
+  return true;
+}
+
+  /* Error out if return value is passed on the stack.  */
+  ret_type = TREE_TYPE (fntype);
+  if (arm_return_in_memory (ret_type, fntype))
+{
+  error ("%qE attribute not available to functions that return value on "
+ "the stack", name);
+  return true;
+}
+  return false;
+}
+
+/* Called upon

Re: [PATCHv2 2/7, GCC, ARM, V8M] Handling ARMv8-M Security Extension's cmse_nonsecure_entry attribute

2016-10-25 Thread Andre Vieira (lists) 
On 24/08/16 12:00, Andre Vieira (lists) wrote:
> On 25/07/16 14:21, Andre Vieira (lists) wrote:
>> This patch adds support for the ARMv8-M Security Extensions
>> 'cmse_nonsecure_entry' attribute. In this patch we implement the
>> attribute handling and diagnosis around the attribute. See Section 5.4
>> of ARM®v8-M Security Extensions
>> (http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/index.html).
>>
>> *** gcc/ChangeLog ***
>> 2016-07-25  Andre Vieira
>> Thomas Preud'homme  
>>
>> * config/arm/arm.c (arm_handle_cmse_nonsecure_entry): New.
>> (arm_attribute_table): Added cmse_nonsecure_entry
>> (arm_compute_func_type): Handle cmse_nonsecure_entry.
>> (cmse_func_args_or_return_in_stack): New.
>> (arm_handle_cmse_nonsecure_entry): New.
>> * config/arm/arm.h (ARM_FT_CMSE_ENTRY): New macro define.
>> (IS_CMSE_ENTRY): Likewise.
>>
>> *** gcc/testsuite/ChangeLog ***
>> 2016-07-25  Andre Vieira
>> Thomas Preud'homme  
>>
>> * gcc.target/arm/cmse/cmse-3.c: New.
>>
> 
> Added more documentation as requested.
> 
> 
> 
> This patch adds support for the ARMv8-M Security Extensions
> 'cmse_nonsecure_entry' attribute. In this patch we implement the
> attribute handling and diagnosis around the attribute. See Section 5.4
> of ARM®v8-M Security Extensions
> (http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/index.html).
> 
> *** gcc/ChangeLog ***
> 2016-07-xx  Andre Vieira
> Thomas Preud'homme  
> 
> * config/arm/arm.c (arm_handle_cmse_nonsecure_entry): New.
> (arm_attribute_table): Added cmse_nonsecure_entry
> (arm_compute_func_type): Handle cmse_nonsecure_entry.
> (cmse_func_args_or_return_in_stack): New.
> (arm_handle_cmse_nonsecure_entry): New.
> * config/arm/arm.h (ARM_FT_CMSE_ENTRY): New macro define.
> (IS_CMSE_ENTRY): Likewise.
> * doc/extend.texi (ARM ARMv8-M Security Extensions): New attribute.
> 
> *** gcc/testsuite/ChangeLog ***
> 2016-07-xx  Andre Vieira
> Thomas Preud'homme  
> 
> * gcc.target/arm/cmse/cmse-3.c: New.
> 
Hi,

Rebased previous patch on top of trunk as requested. No changes to
ChangeLog.

Cheers,
Andre
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 
a370dccdaa9fa4c980c1df11cb95a65cad16ac85..44d1ac45b03dec210e6986f103bf8588119a8aa8
 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -1386,6 +1386,7 @@ enum reg_class
 #define ARM_FT_VOLATILE(1 << 4) /* Does not return.  */
 #define ARM_FT_NESTED  (1 << 5) /* Embedded inside another func.  */
 #define ARM_FT_STACKALIGN  (1 << 6) /* Called with misaligned stack.  */
+#define ARM_FT_CMSE_ENTRY  (1 << 7) /* ARMv8-M non-secure entry function.  
*/
 
 /* Some macros to test these flags.  */
 #define ARM_FUNC_TYPE(t)   (t & ARM_FT_TYPE_MASK)
@@ -1394,6 +1395,7 @@ enum reg_class
 #define IS_NAKED(t)(t & ARM_FT_NAKED)
 #define IS_NESTED(t)   (t & ARM_FT_NESTED)
 #define IS_STACKALIGN(t)   (t & ARM_FT_STACKALIGN)
+#define IS_CMSE_ENTRY(t)   (t & ARM_FT_CMSE_ENTRY)
 
 
 /* Structure used to hold the function stack frame layout.  Offsets are
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 
44677c1bccad42c5ad603ea0951d62abcbd6f05d..996f917ae1dc8e16f219984738c3ac3f8b42f09f
 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -135,6 +135,7 @@ static tree arm_handle_isr_attribute (tree *, tree, tree, 
int, bool *);
 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
 static tree arm_handle_notshared_attribute (tree *, tree, tree, int, bool *);
 #endif
+static tree arm_handle_cmse_nonsecure_entry (tree *, tree, tree, int, bool *);
 static void arm_output_function_epilogue (FILE *, HOST_WIDE_INT);
 static void arm_output_function_prologue (FILE *, HOST_WIDE_INT);
 static int arm_comp_type_attributes (const_tree, const_tree);
@@ -347,6 +348,9 @@ static const struct attribute_spec arm_attribute_table[] =
   { "notshared",0, 0, false, true, false, arm_handle_notshared_attribute,
 false },
 #endif
+  /* ARMv8-M Security Extensions support.  */
+  { "cmse_nonsecure_entry", 0, 0, true, false, false,
+arm_handle_cmse_nonsecure_entry, false },
   { NULL,   0, 0, false, false, false, NULL, false }
 };
 
@@ -3662,6 +3666,9 @@ arm_compute_func_type (void)
   else
 type |= arm_isr_value (TREE_VALUE (a));
 
+  if (lookup_attribute ("cmse_nonsecure_entry", attr))
+type |= ARM_FT_CMSE_ENTRY;
+
   return type;
 }
 
@@ -6661,6 +6668,110 @@ arm_handle_notshared_attribute (tree *node,
 }
 #endif
 
+/* This function returns true if a function with declaration FNDECL, name
+

[PATCHv2 2/7, GCC, ARM, V8M] Handling ARMv8-M Security Extension's cmse_nonsecure_entry attribute

2016-08-24 Thread Andre Vieira (lists) 
On 25/07/16 14:21, Andre Vieira (lists) wrote:
> This patch adds support for the ARMv8-M Security Extensions
> 'cmse_nonsecure_entry' attribute. In this patch we implement the
> attribute handling and diagnosis around the attribute. See Section 5.4
> of ARM®v8-M Security Extensions
> (http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/index.html).
> 
> *** gcc/ChangeLog ***
> 2016-07-25  Andre Vieira
> Thomas Preud'homme  
> 
> * config/arm/arm.c (arm_handle_cmse_nonsecure_entry): New.
> (arm_attribute_table): Added cmse_nonsecure_entry
> (arm_compute_func_type): Handle cmse_nonsecure_entry.
> (cmse_func_args_or_return_in_stack): New.
> (arm_handle_cmse_nonsecure_entry): New.
> * config/arm/arm.h (ARM_FT_CMSE_ENTRY): New macro define.
> (IS_CMSE_ENTRY): Likewise.
> 
> *** gcc/testsuite/ChangeLog ***
> 2016-07-25  Andre Vieira
> Thomas Preud'homme  
> 
> * gcc.target/arm/cmse/cmse-3.c: New.
>

Added more documentation as requested.



This patch adds support for the ARMv8-M Security Extensions
'cmse_nonsecure_entry' attribute. In this patch we implement the
attribute handling and diagnosis around the attribute. See Section 5.4
of ARM®v8-M Security Extensions
(http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/index.html).

*** gcc/ChangeLog ***
2016-07-xx  Andre Vieira
Thomas Preud'homme  

* config/arm/arm.c (arm_handle_cmse_nonsecure_entry): New.
(arm_attribute_table): Added cmse_nonsecure_entry
(arm_compute_func_type): Handle cmse_nonsecure_entry.
(cmse_func_args_or_return_in_stack): New.
(arm_handle_cmse_nonsecure_entry): New.
* config/arm/arm.h (ARM_FT_CMSE_ENTRY): New macro define.
(IS_CMSE_ENTRY): Likewise.
* doc/extend.texi (ARM ARMv8-M Security Extensions): New attribute.

*** gcc/testsuite/ChangeLog ***
2016-07-xx  Andre Vieira
Thomas Preud'homme  

* gcc.target/arm/cmse/cmse-3.c: New.
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 
e3697bbcb425999db31ac2b4f47e14bb3f2ffa89..5307ec8f904230db5ea44150ef471d928926ab6d
 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -1373,6 +1373,7 @@ enum reg_class
 #define ARM_FT_VOLATILE(1 << 4) /* Does not return.  */
 #define ARM_FT_NESTED  (1 << 5) /* Embedded inside another func.  */
 #define ARM_FT_STACKALIGN  (1 << 6) /* Called with misaligned stack.  */
+#define ARM_FT_CMSE_ENTRY  (1 << 7) /* ARMv8-M non-secure entry function.  
*/
 
 /* Some macros to test these flags.  */
 #define ARM_FUNC_TYPE(t)   (t & ARM_FT_TYPE_MASK)
@@ -1381,6 +1382,7 @@ enum reg_class
 #define IS_NAKED(t)(t & ARM_FT_NAKED)
 #define IS_NESTED(t)   (t & ARM_FT_NESTED)
 #define IS_STACKALIGN(t)   (t & ARM_FT_STACKALIGN)
+#define IS_CMSE_ENTRY(t)   (t & ARM_FT_CMSE_ENTRY)
 
 
 /* Structure used to hold the function stack frame layout.  Offsets are
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 
9903d9cd8c5ff68a2318a643bdf31cf48016eba4..11417ab3c2f7101866ee5d6b100913480e5c336e
 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -134,6 +134,7 @@ static tree arm_handle_isr_attribute (tree *, tree, tree, 
int, bool *);
 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
 static tree arm_handle_notshared_attribute (tree *, tree, tree, int, bool *);
 #endif
+static tree arm_handle_cmse_nonsecure_entry (tree *, tree, tree, int, bool *);
 static void arm_output_function_epilogue (FILE *, HOST_WIDE_INT);
 static void arm_output_function_prologue (FILE *, HOST_WIDE_INT);
 static int arm_comp_type_attributes (const_tree, const_tree);
@@ -343,6 +344,9 @@ static const struct attribute_spec arm_attribute_table[] =
   { "notshared",0, 0, false, true, false, arm_handle_notshared_attribute,
 false },
 #endif
+  /* ARMv8-M Security Extensions support.  */
+  { "cmse_nonsecure_entry", 0, 0, true, false, false,
+arm_handle_cmse_nonsecure_entry, false },
   { NULL,   0, 0, false, false, false, NULL, false }
 };
 
@@ -3633,6 +3637,9 @@ arm_compute_func_type (void)
   else
 type |= arm_isr_value (TREE_VALUE (a));
 
+  if (lookup_attribute ("cmse_nonsecure_entry", attr))
+type |= ARM_FT_CMSE_ENTRY;
+
   return type;
 }
 
@@ -6634,6 +6641,110 @@ arm_handle_notshared_attribute (tree *node,
 }
 #endif
 
+/* This function returns true if a function with declaration FNDECL, name
+   NAME and type FNTYPE uses the stack to pass arguments or return variables
+   and false otherwise.  This is used for functions with the attributes
+   'cmse_nonsecure_call' or 'cmse_nonsecure_entry' and this function will