From 9ad1f699b81ce32d1193301ee2c0c188abf64d28 Mon Sep 17 00:00:00 2001 From: Andre Vieira Date: Fri, 2 Dec 2016 15:27:03 +0000 Subject: [PATCH] ARMv8-M Security Extension's cmse_nonsecure_entry: __acle_se label and bxns return gcc/ChangeLog: 2016-12-02 Andre Vieira Thomas Preud'homme * config/arm/arm.c (use_return_insn): Change to return with bxns when cmse_nonsecure_entry. (output_return_instruction): Likewise. (arm_output_function_prologue): Likewise. (thumb_pop): Likewise. (thumb_exit): Likewise. (thumb2_expand_return): Assert that entry functions always have simple returns. (arm_expand_epilogue): Handle entry functions. (arm_function_ok_for_sibcall): Disable sibcall for entry functions. (arm_asm_declare_function_name): New. * config/arm/arm-protos.h (arm_asm_declare_function_name): New. * config/arm/elf.h (ASM_DECLARE_FUNCTION_NAME): Redefine to use arm_asm_declare_function_name. gcc/testsuite/ChangeLog: 2016-12-02 Andre Vieira Thomas Preud'homme * gcc.target/arm/cmse/cmse-4.c: New. * gcc.target/arm/cmse/cmse-9.c: New. * gcc.target/arm/cmse/cmse-10.c: New. Co-Authored-By: Thomas Preud'homme From-SVN: r243189 --- gcc/ChangeLog | 18 +++++++ gcc/config/arm/arm-protos.h | 1 + gcc/config/arm/arm.c | 83 +++++++++++++++++++++++++---- gcc/config/arm/elf.h | 11 +--- gcc/testsuite/ChangeLog | 7 +++ gcc/testsuite/gcc.target/arm/cmse/cmse-10.c | 9 ++++ gcc/testsuite/gcc.target/arm/cmse/cmse-4.c | 27 ++++++++++ gcc/testsuite/gcc.target/arm/cmse/cmse-9.c | 12 +++++ 8 files changed, 148 insertions(+), 20 deletions(-) create mode 100644 gcc/testsuite/gcc.target/arm/cmse/cmse-10.c create mode 100644 gcc/testsuite/gcc.target/arm/cmse/cmse-4.c create mode 100644 gcc/testsuite/gcc.target/arm/cmse/cmse-9.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7eb56d2..eeb8c3c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,6 +1,24 @@ 2016-12-02 Andre Vieira Thomas Preud'homme + * config/arm/arm.c (use_return_insn): Change to return with bxns + when cmse_nonsecure_entry. + (output_return_instruction): Likewise. + (arm_output_function_prologue): Likewise. + (thumb_pop): Likewise. + (thumb_exit): Likewise. + (thumb2_expand_return): Assert that entry functions always have simple + returns. + (arm_expand_epilogue): Handle entry functions. + (arm_function_ok_for_sibcall): Disable sibcall for entry functions. + (arm_asm_declare_function_name): New. + * config/arm/arm-protos.h (arm_asm_declare_function_name): New. + * config/arm/elf.h (ASM_DECLARE_FUNCTION_NAME): Redefine to + use arm_asm_declare_function_name. + +2016-12-02 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. diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h index 68e9bea..634a5de 100644 --- a/gcc/config/arm/arm-protos.h +++ b/gcc/config/arm/arm-protos.h @@ -33,6 +33,7 @@ extern int arm_volatile_func (void); extern void arm_expand_prologue (void); extern void arm_expand_epilogue (bool); extern void arm_declare_function_name (FILE *, const char *, tree); +extern void arm_asm_declare_function_name (FILE *, const char *, tree); extern void thumb2_expand_return (bool); extern const char *arm_strip_name_encoding (const char *); extern void arm_asm_output_labelref (FILE *, const char *); diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c index 7761564..db7e0c8 100644 --- a/gcc/config/arm/arm.c +++ b/gcc/config/arm/arm.c @@ -3866,6 +3866,11 @@ use_return_insn (int iscond, rtx sibling) return 0; } + /* ARMv8-M nonsecure entry function need to use bxns to return and thus need + several instructions if anything needs to be popped. */ + if (saved_int_regs && IS_CMSE_ENTRY (func_type)) + return 0; + /* If there are saved registers but the LR isn't saved, then we need two instructions for the return. */ if (saved_int_regs && !(saved_int_regs & (1 << LR_REGNUM))) @@ -6906,6 +6911,11 @@ arm_function_ok_for_sibcall (tree decl, tree exp) if (IS_INTERRUPT (func_type)) return false; + /* ARMv8-M non-secure entry functions need to return with bxns which is only + generated for entry functions themselves. */ + if (IS_CMSE_ENTRY (arm_current_func_type ())) + return false; + if (!VOID_TYPE_P (TREE_TYPE (DECL_RESULT (cfun->decl)))) { /* Check that the return value locations are the same. For @@ -18568,6 +18578,7 @@ output_return_instruction (rtx operand, bool really_return, bool reverse, (e.g. interworking) then we can load the return address directly into the PC. Otherwise we must load it into LR. */ if (really_return + && !IS_CMSE_ENTRY (func_type) && (IS_INTERRUPT (func_type) || !TARGET_INTERWORK)) return_reg = reg_names[PC_REGNUM]; else @@ -18708,8 +18719,10 @@ output_return_instruction (rtx operand, bool really_return, bool reverse, break; default: + if (IS_CMSE_ENTRY (func_type)) + snprintf (instr, sizeof (instr), "bxns%s\t%%|lr", conditional); /* Use bx if it's available. */ - if (arm_arch5 || arm_arch4t) + else if (arm_arch5 || arm_arch4t) sprintf (instr, "bx%s\t%%|lr", conditional); else sprintf (instr, "mov%s\t%%|pc, %%|lr", conditional); @@ -18722,6 +18735,44 @@ output_return_instruction (rtx operand, bool really_return, bool reverse, return ""; } +/* Output in FILE asm statements needed to declare the NAME of the function + defined by its DECL node. */ + +void +arm_asm_declare_function_name (FILE *file, const char *name, tree decl) +{ + size_t cmse_name_len; + char *cmse_name = 0; + char cmse_prefix[] = "__acle_se_"; + + /* When compiling with ARMv8-M Security Extensions enabled, we should print an + extra function label for each function with the 'cmse_nonsecure_entry' + attribute. This extra function label should be prepended with + '__acle_se_', telling the linker that it needs to create secure gateway + veneers for this function. */ + if (use_cmse && lookup_attribute ("cmse_nonsecure_entry", + DECL_ATTRIBUTES (decl))) + { + cmse_name_len = sizeof (cmse_prefix) + strlen (name); + cmse_name = XALLOCAVEC (char, cmse_name_len); + snprintf (cmse_name, cmse_name_len, "%s%s", cmse_prefix, name); + targetm.asm_out.globalize_label (file, cmse_name); + + ARM_DECLARE_FUNCTION_NAME (file, cmse_name, decl); + ASM_OUTPUT_TYPE_DIRECTIVE (file, cmse_name, "function"); + } + + ARM_DECLARE_FUNCTION_NAME (file, name, decl); + ASM_OUTPUT_TYPE_DIRECTIVE (file, name, "function"); + ASM_DECLARE_RESULT (file, DECL_RESULT (decl)); + ASM_OUTPUT_LABEL (file, name); + + if (cmse_name) + ASM_OUTPUT_LABEL (file, cmse_name); + + ARM_OUTPUT_FN_UNWIND (file, TRUE); +} + /* Write the function name into the code section, directly preceding the function prologue. @@ -18771,10 +18822,6 @@ arm_output_function_prologue (FILE *f, HOST_WIDE_INT frame_size) { unsigned long func_type; - /* ??? Do we want to print some of the below anyway? */ - if (TARGET_THUMB1) - return; - /* Sanity check. */ gcc_assert (!arm_ccfsm_state && !arm_target_insn); @@ -18809,6 +18856,8 @@ arm_output_function_prologue (FILE *f, HOST_WIDE_INT frame_size) asm_fprintf (f, "\t%@ Nested: function declared inside another function.\n"); if (IS_STACKALIGN (func_type)) asm_fprintf (f, "\t%@ Stack Align: May be called with mis-aligned SP.\n"); + if (IS_CMSE_ENTRY (func_type)) + asm_fprintf (f, "\t%@ Non-secure entry function: called from non-secure code.\n"); asm_fprintf (f, "\t%@ args = %d, pretend = %d, frame = %wd\n", crtl->args.size, @@ -22915,8 +22964,8 @@ thumb_pop (FILE *f, unsigned long mask) if (mask & (1 << PC_REGNUM)) { /* Catch popping the PC. */ - if (TARGET_INTERWORK || TARGET_BACKTRACE - || crtl->calls_eh_return) + if (TARGET_INTERWORK || TARGET_BACKTRACE || crtl->calls_eh_return + || IS_CMSE_ENTRY (arm_current_func_type ())) { /* The PC is never poped directly, instead it is popped into r3 and then BX is used. */ @@ -22977,7 +23026,10 @@ thumb_exit (FILE *f, int reg_containing_return_addr) if (crtl->calls_eh_return) asm_fprintf (f, "\tadd\t%r, %r\n", SP_REGNUM, ARM_EH_STACKADJ_REGNUM); - asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr); + if (IS_CMSE_ENTRY (arm_current_func_type ())) + asm_fprintf (f, "\tbxns\t%r\n", reg_containing_return_addr); + else + asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr); return; } /* Otherwise if we are not supporting interworking and we have not created @@ -22986,7 +23038,8 @@ thumb_exit (FILE *f, int reg_containing_return_addr) else if (!TARGET_INTERWORK && !TARGET_BACKTRACE && !is_called_in_ARM_mode (current_function_decl) - && !crtl->calls_eh_return) + && !crtl->calls_eh_return + && !IS_CMSE_ENTRY (arm_current_func_type ())) { asm_fprintf (f, "\tpop\t{%r}\n", PC_REGNUM); return; @@ -23209,7 +23262,10 @@ thumb_exit (FILE *f, int reg_containing_return_addr) asm_fprintf (f, "\tadd\t%r, %r\n", SP_REGNUM, ARM_EH_STACKADJ_REGNUM); /* Return to caller. */ - asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr); + if (IS_CMSE_ENTRY (arm_current_func_type ())) + asm_fprintf (f, "\tbxns\t%r\n", reg_containing_return_addr); + else + asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr); } /* Scan INSN just before assembler is output for it. @@ -24095,6 +24151,12 @@ thumb2_expand_return (bool simple_return) if (!simple_return && saved_regs_mask) { + /* TODO: Verify that this path is never taken for cmse_nonsecure_entry + functions or adapt code to handle according to ACLE. This path should + not be reachable for cmse_nonsecure_entry functions though we prefer + to assert it for now to ensure that future code changes do not silently + change this behavior. */ + gcc_assert (!IS_CMSE_ENTRY (arm_current_func_type ())); if (num_regs == 1) { rtx par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (2)); @@ -24512,6 +24574,7 @@ arm_expand_epilogue (bool really_return) if (ARM_FUNC_TYPE (func_type) != ARM_FT_INTERWORKED && (TARGET_ARM || ARM_FUNC_TYPE (func_type) == ARM_FT_NORMAL) + && !IS_CMSE_ENTRY (func_type) && !IS_STACKALIGN (func_type) && really_return && crtl->args.pretend_args_size == 0 diff --git a/gcc/config/arm/elf.h b/gcc/config/arm/elf.h index bc4eb86..03931ee 100644 --- a/gcc/config/arm/elf.h +++ b/gcc/config/arm/elf.h @@ -75,16 +75,7 @@ /* We might need a ARM specific header to function declarations. */ #undef ASM_DECLARE_FUNCTION_NAME -#define ASM_DECLARE_FUNCTION_NAME(FILE, NAME, DECL) \ - do \ - { \ - ARM_DECLARE_FUNCTION_NAME (FILE, NAME, DECL); \ - ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "function"); \ - ASM_DECLARE_RESULT (FILE, DECL_RESULT (DECL)); \ - ASM_OUTPUT_LABEL(FILE, NAME); \ - ARM_OUTPUT_FN_UNWIND (FILE, TRUE); \ - } \ - while (0) +#define ASM_DECLARE_FUNCTION_NAME arm_asm_declare_function_name /* We might need an ARM specific trailer for function declarations. */ #undef ASM_DECLARE_FUNCTION_SIZE diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 4e1240e..e31a1b3 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,6 +1,13 @@ 2016-12-02 Andre Vieira Thomas Preud'homme + * gcc.target/arm/cmse/cmse-4.c: New. + * gcc.target/arm/cmse/cmse-9.c: New. + * gcc.target/arm/cmse/cmse-10.c: New. + +2016-12-02 Andre Vieira + Thomas Preud'homme + * gcc.target/arm/cmse/cmse-3.c: New. 2016-12-02 Andre Vieira diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-10.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-10.c new file mode 100644 index 0000000..1a91ac3 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-10.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-mcmse" } */ + +void +foo (void) {} + +/* { dg-final { scan-assembler-not "bxns" } } */ +/* { dg-final { scan-assembler "foo:" } } */ +/* { dg-final { scan-assembler-not "__acle_se_foo:" } } */ diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c new file mode 100644 index 0000000..6f930ab --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-4.c @@ -0,0 +1,27 @@ +/* { dg-do compile } */ +/* { dg-options "-mcmse" } */ + +struct span { + int a, b; +}; + +extern int qux (void); + +void __attribute__ ((cmse_nonsecure_entry)) +foo (void) {} + +static void __attribute__ ((cmse_nonsecure_entry)) +bar (void) {} /* { dg-warning "has no effect on functions with static linkage" } */ + +int __attribute__ ((cmse_nonsecure_entry)) +baz (void) +{ + return qux (); +} + +/* { 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:" } } */ diff --git a/gcc/testsuite/gcc.target/arm/cmse/cmse-9.c b/gcc/testsuite/gcc.target/arm/cmse/cmse-9.c new file mode 100644 index 0000000..1d97f0e --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-9.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-skip-if "Testing exclusion of -mcmse" { arm-*-* } { "-mcmse" } { "" } } */ + + +int __attribute__ ((cmse_nonsecure_entry)) +foo (int a) +{ /* { dg-warning "attribute ignored without -mcmse option" } */ + return a + 1; +} + +/* { dg-final { scan-assembler "foo:" } } */ +/* { dg-final { scan-assembler-not "__acle_se_foo:" } } */ -- 2.7.4