This patch adds support ARMv8-M's Security Extension's
cmse_nonsecure_caller intrinsic. This intrinsic is used to check whether
an entry function was called from a non-secure state.
See Section 5.4.3 of ARM®v8-M Security Extensions: Requirements on
Development Tools
(http://infocenter.arm.com/help/topic/com.arm.doc.ecm0359818/index.html)
for further details.
The FIXME in config/arm/arm_cmse.h is for a diagnostic message that is
suggested in the ARMv8-M Security Extensions document mentioned above,
to diagnose the use of the cmse_nonsecure_caller intrinsic outside of
functions with the 'cmse_nonsecure_entry' attribute. Checking whether
the intrinsic is called from within such functions can easily be done
inside 'arm_expand_builtin'. However, making the warning point to the
right location is more complicated. The ARMv8-M Security Extensions
specification does mention that such a diagnostic might become
mandatory, so I might have to pick this up later, otherwise it is left
as a potential extra feature.
*** gcc/ChangeLog ***
2016-07-25 Andre Vieira <andre.simoesdiasvie...@arm.com>
Thomas Preud'homme <thomas.preudho...@arm.com>
* config/arm/arm-builtins.c (arm_builtins): Define
ARM_BUILTIN_CMSE_NONSECURE_CALLER.
(bdesc_2arg): Add line for cmse_nonsecure_caller.
(arm_expand_builtin): Handle cmse_nonsecure_caller.
* config/arm/arm_cmse.h (cmse_nonsecure_caller): New.
*** gcc/testsuite/ChangeLog ***
2016-07-25 Andre Vieira <andre.simoesdiasvie...@arm.com>
Thomas Preud'homme <thomas.preudho...@arm.com>
* gcc.target/arm/cmse/cmse-1.c: Add test for
cmse_nonsecure_caller.
diff --git a/gcc/config/arm/arm-builtins.c b/gcc/config/arm/arm-builtins.c
index
68b2839879f78e8d819444fbc11d2a91f8d6279a..2589ec2d1233f3daff94a1d35ebf63c8a9b93ecf
100644
--- a/gcc/config/arm/arm-builtins.c
+++ b/gcc/config/arm/arm-builtins.c
@@ -515,6 +515,8 @@ enum arm_builtins
ARM_BUILTIN_GET_FPSCR,
ARM_BUILTIN_SET_FPSCR,
+ ARM_BUILTIN_CMSE_NONSECURE_CALLER,
+
#undef CRYPTO1
#undef CRYPTO2
#undef CRYPTO3
@@ -1789,6 +1791,17 @@ arm_init_builtins (void)
= add_builtin_function ("__builtin_arm_stfscr", ftype_set_fpscr,
ARM_BUILTIN_SET_FPSCR, BUILT_IN_MD, NULL,
NULL_TREE);
}
+
+ if (arm_arch_cmse)
+ {
+ tree ftype_cmse_nonsecure_caller
+ = build_function_type_list (unsigned_type_node, NULL);
+ arm_builtin_decls[ARM_BUILTIN_CMSE_NONSECURE_CALLER]
+ = add_builtin_function ("__builtin_arm_cmse_nonsecure_caller",
+ ftype_cmse_nonsecure_caller,
+ ARM_BUILTIN_CMSE_NONSECURE_CALLER, BUILT_IN_MD,
+ NULL, NULL_TREE);
+ }
}
/* Return the ARM builtin for CODE. */
@@ -2368,6 +2381,12 @@ arm_expand_builtin (tree exp,
emit_insn (pat);
return target;
+ case ARM_BUILTIN_CMSE_NONSECURE_CALLER:
+ target = gen_reg_rtx (SImode);
+ op0 = arm_return_addr (0, NULL_RTX);
+ emit_insn (gen_addsi3 (target, op0, const1_rtx));
+ return target;
+
case ARM_BUILTIN_TEXTRMSB:
case ARM_BUILTIN_TEXTRMUB:
case ARM_BUILTIN_TEXTRMSH:
diff --git a/gcc/config/arm/arm_cmse.h b/gcc/config/arm/arm_cmse.h
index
c9afdcbf48160a963fc254795543a1d9e981a215..989d09f9d08268224e745da5a2e0aa85916cd3a9
100644
--- a/gcc/config/arm/arm_cmse.h
+++ b/gcc/config/arm/arm_cmse.h
@@ -163,6 +163,13 @@ __attribute__ ((__always_inline__))
cmse_TTAT (void *__p)
__CMSE_TT_ASM (at)
+/* FIXME: diagnose use outside cmse_nonsecure_entry functions. */
+__extension__ static __inline int __attribute__ ((__always_inline__))
+cmse_nonsecure_caller (void)
+{
+ return __builtin_arm_cmse_nonsecure_caller ();
+}
+
#define CMSE_AU_NONSECURE 2
#define CMSE_MPU_NONSECURE 16
#define CMSE_NONSECURE 18
@@ -177,7 +184,7 @@ __extension__ void *
cmse_check_address_range (void *, size_t, int);
#define cmse_check_pointed_object(p, f) \
- ((typeof ((p))) cmse_check_address_range ((p), sizeof (*(p)), (f)))
+ ((typeof ((p))) cmse_check_address_range ((p), sizeof (*(p)), (f)))
#define cmse_nsfptr_create(p) ((typeof ((p))) ((intptr_t) (p) & ~1))
diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-1.c
b/gcc/testsuite/gcc.target/arm/cmse/cmse-1.c
index
d5b9a2d9d59569de170da814ae660e9fb2b943e7..ddcf12a30a6c1806969d239c448da81ccf49532e
100644
--- a/gcc/testsuite/gcc.target/arm/cmse/cmse-1.c
+++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-1.c
@@ -65,3 +65,32 @@ int foo (char * p)
/* { dg-final { scan-assembler-times "ttat " 2 } } */
/* { dg-final { scan-assembler-times "bl.cmse_check_address_range" 7 } } */
/* { dg-final { scan-assembler-not "cmse_check_pointed_object" } } */
+
+typedef int (*int_ret_funcptr_t) (void);
+typedef int __attribute__ ((cmse_nonsecure_call)) (*int_ret_nsfuncptr_t)
(void);
+
+int __attribute__ ((cmse_nonsecure_entry))
+baz (void)
+{
+ return cmse_nonsecure_caller ();
+}
+
+int __attribute__ ((cmse_nonsecure_entry))
+qux (int_ret_funcptr_t int_ret_funcptr)
+{
+ int_ret_nsfuncptr_t int_ret_nsfunc_ptr;
+
+ if (cmse_is_nsfptr (int_ret_funcptr))
+ {
+ int_ret_nsfunc_ptr = cmse_nsfptr_create (int_ret_funcptr);
+ return int_ret_nsfunc_ptr ();
+ }
+ return 0;
+}
+/* { dg-final { scan-assembler "baz:" } } */
+/* { dg-final { scan-assembler "__acle_se_baz:" } } */
+/* { dg-final { scan-assembler-not "\tcmse_nonsecure_caller" } } */
+/* { dg-final { scan-rtl-dump "and.*reg.*const_int 1" expand } } */
+/* { dg-final { scan-assembler "bic" } } */
+/* { dg-final { scan-assembler "push\t\{r4, r5, r6" } } */
+/* { dg-final { scan-assembler "msr\tAPSR_nzcvq" } } */
