| Message ID | 580F8836.1050203@arm.com |
|---|---|
| State | New |
| Headers | show |
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 <andre.simoesdiasvieira@arm.com> >>> Thomas Preud'homme <thomas.preudhomme@arm.com> >>> >>> * 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 <andre.simoesdiasvieira@arm.com> >>> Thomas Preud'homme <thomas.preudhomme@arm.com> >>> >>> * 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 <andre.simoesdiasvieira@arm.com> >> Thomas Preud'homme <thomas.preudhomme@arm.com> >> >> * 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 <andre.simoesdiasvieira@arm.com> >> Thomas Preud'homme <thomas.preudhomme@arm.com> >> >> * 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 (&args_so_far_v, fntype, NULL_RTX, fndecl); + args_so_far = pack_cumulative_args (&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 detection of the use of the cmse_nonsecure_entry attribute, this + function will check whether the attribute is allowed here and will add the + attribute to the function declaration tree or otherwise issue a warning. */ + +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. Thanks, Kyrill
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_name> attribute ignored without -mcmse option." Cheers, Andre
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_name> attribute ignored without -mcmse option." Yes, that's fine (without the full stop at the end) Kyrill > 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 + 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. */ + +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 (&args_so_far_v, fntype, NULL_RTX, fndecl); + args_so_far = pack_cumulative_args (&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 detection of the use of the cmse_nonsecure_entry attribute, this + function will check whether the attribute is allowed here and will add the + attribute to the function declaration tree or otherwise issue a warning. */ + +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; + } + + /* Ignore attribute for function types. */ + if (TREE_CODE (*node) != FUNCTION_DECL) + { + warning (OPT_Wattributes, "%qE attribute only applies to functions", + name); + *no_add_attrs = true; + return NULL_TREE; + } + + fndecl = *node; + + /* Warn for static linkage functions. */ + if (!TREE_PUBLIC (fndecl)) + { + warning (OPT_Wattributes, "%qE attribute has no effect on functions " + "with static linkage", name); + *no_add_attrs = true; + return NULL_TREE; + } + + *no_add_attrs |= cmse_func_args_or_return_in_stack (fndecl, name, + TREE_TYPE (fndecl)); + 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). */ diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 3f6fc27950fafa2e7649deb9dc5db44737cbb691..e5b28032e5610b896908139ec285ce90a9dffd8a 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -12607,6 +12607,9 @@ 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 the intrinsics below. FPTR is used here to mean any function pointer type. diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-3.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-3.c new file mode 100644 index 0000000000000000000000000000000000000000..2c2920e1dc310106d83203eb51e1a68a275d0152 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-3.c @@ -0,0 +1,37 @@ +/* { dg-do compile } */ +/* { dg-options "-mcmse" } */ + +struct span { + int a, b; +}; +struct span2 { + float a, b, c, d; +}; + +union test_union +{ + long long a; + int b; + struct span2 c; +} test_union; + +void __attribute__ ((cmse_nonsecure_entry)) +foo (long long a, int b, long long c) {} /* { dg-error "not available to functions with arguments passed on the stack" } */ + +void __attribute__ ((cmse_nonsecure_entry)) +bar (long long a, int b, struct span c) {} /* { dg-error "not available to functions with arguments passed on the stack" } */ + +void __attribute__ ((cmse_nonsecure_entry)) +baz (int a, ...) {} /* { dg-error "not available to functions with variable number of arguments" } */ + +struct span __attribute__ ((cmse_nonsecure_entry)) +qux (void) { /* { dg-error "not available to functions that return value on the stack" } */ + struct span ret = {0, 0}; + return ret; +} + +void __attribute__ ((cmse_nonsecure_entry)) +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" } */