Hi, I got a bug report against the old version of this patch and fixed it here. This had to do with GCC optimizations sharing types with and without the 'cmse_nonsecure_call' attribute. The patch now no longer sets the main variant, this didn't seem to do what I thought it did. Instead the patch now creates distinct type copies for every declared pointer that eventually points to the function type with the attribute, it will also create a distinct copy for the function type itself. Another change in this patch was to make 'arm_comp_type_attributes', the ARM implementation of TARGET_COMP_TYPE_ATTRIBUTES, deny compatibility between function types with the attribute and without.
I added a test case to test the issue solved with these changes. *** gcc/ChangeLog *** 2016-11-xx Andre Vieira <andre.simoesdiasvie...@arm.com> Thomas Preud'homme <thomas.preudho...@arm.com> * config/arm/arm.c (gimplify.h): New include. (arm_handle_cmse_nonsecure_call): New. (arm_attribute_table): Added cmse_nonsecure_call. (arm_comp_type_attributes): Deny compatibility of function types with without the cmse_nonsecure_call attribute. * doc/extend.texi (ARM ARMv8-M Security Extensions): New attribute. *** gcc/testsuite/ChangeLog *** 2016-11-xx Andre Vieira <andre.simoesdiasvie...@arm.com> Thomas Preud'homme <thomas.preudho...@arm.com> * gcc.target/arm/cmse/cmse-3.c: Add tests. * gcc.target/arm/cmse/cmse-4.c: Add tests. * gcc.target/arm/cmse/cmse-15.c: New. Cheers, Andre
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 9509b0e25c19f35ed312efa1d86efc18a0db7674..d1160d5001830beea981df7454f09daf7fac2c5a 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -63,6 +63,7 @@ #include "tm-constrs.h" #include "rtl-iter.h" #include "optabs-libfuncs.h" +#include "gimplify.h" /* This file should be included last. */ #include "target-def.h" @@ -137,6 +138,7 @@ static tree arm_handle_isr_attribute (tree *, tree, tree, int, bool *); 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 tree arm_handle_cmse_nonsecure_call (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); @@ -348,6 +350,8 @@ static const struct attribute_spec arm_attribute_table[] = /* ARMv8-M Security Extensions support. */ { "cmse_nonsecure_entry", 0, 0, true, false, false, arm_handle_cmse_nonsecure_entry, false }, + { "cmse_nonsecure_call", 0, 0, true, false, false, + arm_handle_cmse_nonsecure_call, true }, { NULL, 0, 0, false, false, false, NULL, false } }; @@ -6753,6 +6757,78 @@ arm_handle_cmse_nonsecure_entry (tree *node, tree name, return NULL_TREE; } + +/* Called upon detection of the use of the cmse_nonsecure_call attribute, this + function will check whether the attribute is allowed here and will add the + attribute to the function type tree or otherwise issue a diagnostic. The + reason we check this at declaration time is to only allow the use of the + attribute with declarations of function pointers and not function + declarations. This function checks NODE is of the expected type and issues + diagnostics otherwise using NAME. If it is not of the expected type + *NO_ADD_ATTRS will be set to true. */ + +static tree +arm_handle_cmse_nonsecure_call (tree *node, tree name, + tree /* args */, + int /* flags */, + bool *no_add_attrs) +{ + tree decl = NULL_TREE, fntype = NULL_TREE; + tree main_variant, type; + + if (!use_cmse) + { + *no_add_attrs = true; + warning (OPT_Wattributes, "%qE attribute ignored without -mcmse option.", + name); + return NULL_TREE; + } + + if (TREE_CODE (*node) == VAR_DECL || TREE_CODE (*node) == TYPE_DECL) + { + decl = *node; + fntype = TREE_TYPE (decl); + } + + while (fntype != NULL_TREE && TREE_CODE (fntype) == POINTER_TYPE) + fntype = TREE_TYPE (fntype); + + if (!decl || TREE_CODE (fntype) != FUNCTION_TYPE) + { + warning (OPT_Wattributes, "%qE attribute only applies to base type of a " + "function pointer", name); + *no_add_attrs = true; + return NULL_TREE; + } + + *no_add_attrs |= cmse_func_args_or_return_in_stack (NULL, name, fntype); + + if (*no_add_attrs) + return NULL_TREE; + + /* Prevent trees being shared among function types with and without + cmse_nonsecure_call attribute. */ + type = TREE_TYPE (decl); + + type = build_distinct_type_copy (type); + TREE_TYPE (decl) = type; + fntype = type; + + while (TREE_CODE (fntype) != FUNCTION_TYPE) + { + type = fntype; + fntype = TREE_TYPE (fntype); + fntype = build_distinct_type_copy (fntype); + TREE_TYPE (type) = fntype; + } + + /* Construct a type attribute and add it to the function type. */ + tree attrs = tree_cons (get_identifier ("cmse_nonsecure_call"), NULL_TREE, + TYPE_ATTRIBUTES (fntype)); + TYPE_ATTRIBUTES (fntype) = attrs; + return NULL_TREE; +} + /* Return 0 if the attributes for two types are incompatible, 1 if they are compatible, and 2 if they are nearly compatible (which causes a warning to be generated). */ @@ -6793,6 +6869,14 @@ arm_comp_type_attributes (const_tree type1, const_tree type2) if (l1 != l2) return 0; + l1 = lookup_attribute ("cmse_nonsecure_call", + TYPE_ATTRIBUTES (type1)) != NULL; + l2 = lookup_attribute ("cmse_nonsecure_call", + TYPE_ATTRIBUTES (type2)) != NULL; + + if (l1 != l2) + return 0; + return 1; } diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index e8d9d90c0ac98a2b50aad60edf01e16dfa480db7..e8d8deefca87eacbdde6042fc1885c0d0a85a5b8 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -12622,8 +12622,8 @@ Security Extensions: Requiremenets on Development Tools Engineering Specification, which can be found at @uref{http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/ECM0359818_armv8m_security_extensions_reqs_on_dev_tools_1_0.pdf}. -As part of the Security Extensions GCC implements a new function attribute -@code{cmse_nonsecure_entry}. +As part of the Security Extensions GCC implements two new function attributes: +@code{cmse_nonsecure_entry} and @code{cmse_nonsecure_call}. As part of the Security Extensions GCC implements the intrinsics below. FPTR is used here to mean any function pointer type. diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-15.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-15.c new file mode 100644 index 0000000000000000000000000000000000000000..4e9ace1f3f33b8a8653797e29ca62eb3dd7ae918 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-15.c @@ -0,0 +1,72 @@ +/* { dg-do compile } */ +/* { dg-options "-mcmse" } */ + +int __attribute__ ((cmse_nonsecure_call)) (*ns_foo) (void); +int (*s_bar) (void); +int __attribute__ ((cmse_nonsecure_call)) (**ns_foo2) (void); +int (**s_bar2) (void); + +typedef int __attribute__ ((cmse_nonsecure_call)) ns_foo_t (void); +typedef int s_bar_t (void); +typedef int __attribute__ ((cmse_nonsecure_call)) (* ns_foo_ptr) (void); +typedef int (*s_bar_ptr) (void); + +int nonsecure0 (ns_foo_t * ns_foo_p) +{ + return ns_foo_p (); +} + +int nonsecure1 (ns_foo_t ** ns_foo_p) +{ + return (*ns_foo_p) (); +} + +int nonsecure2 (ns_foo_ptr ns_foo_p) +{ + return ns_foo_p (); +} +int nonsecure3 (ns_foo_ptr * ns_foo_p) +{ + return (*ns_foo_p) (); +} + +int secure0 (s_bar_t * s_bar_p) +{ + return s_bar_p (); +} + +int secure1 (s_bar_t ** s_bar_p) +{ + return (*s_bar_p) (); +} + +int secure2 (s_bar_ptr s_bar_p) +{ + return s_bar_p (); +} + +int secure3 (s_bar_ptr * s_bar_p) +{ + return (*s_bar_p) (); +} + +int nonsecure4 (void) +{ + return ns_foo (); +} + +int nonsecure5 (void) +{ + return (*ns_foo2) (); +} + +int secure4 (void) +{ + return s_bar (); +} + +int secure5 (void) +{ + return (*s_bar2) (); +} +/* { dg-final { scan-assembler-times "bl\\s+__gnu_cmse_nonsecure_call" 6 } } */ diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-3.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-3.c index 2c2920e1dc310106d83203eb51e1a68a275d0152..7f92a4c28b3333e4c8fdc256211f3ed74a383cd4 100644 --- a/gcc/testsuite/gcc.target/arm/cmse/cmse-3.c +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-3.c @@ -35,3 +35,11 @@ norf (struct span2 a) {} void __attribute__ ((cmse_nonsecure_entry)) foo2 (long long a, int b, union test_union c) {} /* { dg-error "not available to functions with arguments passed on the stack" } */ + +typedef void __attribute__ ((cmse_nonsecure_call)) bar2 (long long a, int b, long long c); /* { dg-error "not available to functions with arguments passed on the stack" } */ + +typedef void __attribute__ ((cmse_nonsecure_call)) baz2 (long long a, int b, struct span c); /* { dg-error "not available to functions with arguments passed on the stack" } */ + +typedef struct span __attribute__ ((cmse_nonsecure_call)) qux2 (void); /* { dg-error "not available to functions that return value on the stack" } */ + +typedef void __attribute__ ((cmse_nonsecure_call)) norf2 (int a, ...); /* { dg-error "not available to functions with variable number of arguments" } */ diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c index 6f930ab04a1097c64097a4e003296bbe85733319..d0999a4181ac022b115ae20cf3e1c8bf78f6becf 100644 --- a/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c @@ -19,9 +19,16 @@ baz (void) return qux (); } +void __attribute__ ((cmse_nonsecure_call)) +quux (void) {} /* { dg-warning "attribute only applies to base type of a function pointer" } */ + +int __attribute__ ((cmse_nonsecure_call)) norf; /* { dg-warning "attribute only applies to base type of a function pointer" } */ + /* { dg-final { scan-assembler-times "bxns" 2 } } */ /* { dg-final { scan-assembler "foo:" } } */ /* { dg-final { scan-assembler "__acle_se_foo:" } } */ /* { dg-final { scan-assembler-not "__acle_se_bar:" } } */ /* { dg-final { scan-assembler "baz:" } } */ /* { dg-final { scan-assembler "__acle_se_baz:" } } */ +/* { dg-final { scan-assembler-not "__acle_se_quux:" } } */ +/* { dg-final { scan-assembler-not "__acle_se_norf:" } } */