diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h index cff7ff1da2a..84764bf27ce 100644 --- a/gcc/config/arm/arm-protos.h +++ b/gcc/config/arm/arm-protos.h @@ -379,6 +379,7 @@ extern int vfp3_const_double_for_bits (rtx); extern void arm_emit_coreregs_64bit_shift (enum rtx_code, rtx, rtx, rtx, rtx, rtx); extern bool arm_fusion_enabled_p (tune_params::fuse_ops); +extern bool arm_current_function_pac_enabled_p (void); extern bool arm_valid_symbolic_address_p (rtx); extern bool arm_validize_comparison (rtx *, rtx *, rtx *); extern bool arm_expand_vector_compare (rtx, rtx_code, rtx, rtx, bool); diff --git a/gcc/config/arm/arm.cc b/gcc/config/arm/arm.cc index a5cf4225aa2..31c6bcdea55 100644 --- a/gcc/config/arm/arm.cc +++ b/gcc/config/arm/arm.cc @@ -3209,6 +3209,9 @@ arm_option_override_internal (struct gcc_options *opts, arm_stack_protector_guard_offset = offs; } + if (arm_current_function_pac_enabled_p () && !(arm_arch7 && arm_arch_cmse)) + error ("This architecture does not support branch protection instructions"); + #ifdef SUBTARGET_OVERRIDE_INTERNAL_OPTIONS SUBTARGET_OVERRIDE_INTERNAL_OPTIONS; #endif @@ -21139,6 +21142,9 @@ arm_compute_save_core_reg_mask (void) save_reg_mask |= arm_compute_save_reg0_reg12_mask (); + if (arm_current_function_pac_enabled_p ()) + save_reg_mask |= 1 << IP_REGNUM; + /* Decide if we need to save the link register. Interrupt routines have their own banked link register, so they never need to save it. @@ -23362,6 +23368,12 @@ output_probe_stack_range (rtx reg1, rtx reg2) return ""; } +static bool +aarch_bti_enabled () +{ + return false; +} + /* Generate the prologue instructions for entry into an ARM or Thumb-2 function. */ void @@ -23440,12 +23452,13 @@ arm_expand_prologue (void) /* The static chain register is the same as the IP register. If it is clobbered when creating the frame, we need to save and restore it. */ - clobber_ip = IS_NESTED (func_type) - && ((TARGET_APCS_FRAME && frame_pointer_needed && TARGET_ARM) - || ((flag_stack_check == STATIC_BUILTIN_STACK_CHECK - || flag_stack_clash_protection) - && !df_regs_ever_live_p (LR_REGNUM) - && arm_r3_live_at_start_p ())); + clobber_ip = (IS_NESTED (func_type) + && (((TARGET_APCS_FRAME && frame_pointer_needed && TARGET_ARM) + || ((flag_stack_check == STATIC_BUILTIN_STACK_CHECK + || flag_stack_clash_protection) + && !df_regs_ever_live_p (LR_REGNUM) + && arm_r3_live_at_start_p ())) + || (arm_current_function_pac_enabled_p ()))); /* Find somewhere to store IP whilst the frame is being created. We try the following places in order: @@ -23521,6 +23534,14 @@ arm_expand_prologue (void) } } + if (arm_current_function_pac_enabled_p ()) + { + if (aarch_bti_enabled ()) + emit_insn (gen_pacbti_nop ()); + else + emit_insn (gen_pac_nop ()); + } + if (TARGET_APCS_FRAME && frame_pointer_needed && TARGET_ARM) { if (IS_INTERRUPT (func_type)) @@ -27309,7 +27330,7 @@ thumb2_expand_return (bool simple_return) 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) + if (num_regs == 1 && !arm_current_function_pac_enabled_p ()) { rtx par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (2)); rtx reg = gen_rtx_REG (SImode, PC_REGNUM); @@ -27324,10 +27345,20 @@ thumb2_expand_return (bool simple_return) } else { - saved_regs_mask &= ~ (1 << LR_REGNUM); - saved_regs_mask |= (1 << PC_REGNUM); - arm_emit_multi_reg_pop (saved_regs_mask); - } + if (arm_current_function_pac_enabled_p ()) + { + gcc_assert (!(saved_regs_mask & (1 << PC_REGNUM))); + arm_emit_multi_reg_pop (saved_regs_mask); + emit_insn (gen_aut_nop ()); + emit_jump_insn (simple_return_rtx); + } + else + { + saved_regs_mask &= ~ (1 << LR_REGNUM); + saved_regs_mask |= (1 << PC_REGNUM); + arm_emit_multi_reg_pop (saved_regs_mask); + } + } } else { @@ -27733,7 +27764,8 @@ arm_expand_epilogue (bool really_return) && really_return && crtl->args.pretend_args_size == 0 && saved_regs_mask & (1 << LR_REGNUM) - && !crtl->calls_eh_return) + && !crtl->calls_eh_return + && !arm_current_function_pac_enabled_p ()) { saved_regs_mask &= ~(1 << LR_REGNUM); saved_regs_mask |= (1 << PC_REGNUM); @@ -27847,6 +27879,9 @@ arm_expand_epilogue (bool really_return) } } + if (arm_current_function_pac_enabled_p ()) + emit_insn (gen_aut_nop ()); + if (!really_return) return; @@ -32941,6 +32976,15 @@ arm_fusion_enabled_p (tune_params::fuse_ops op) return current_tune->fusible_ops & op; } +/* Return TRUE if return address signing mechanism is enabled. */ +bool +arm_current_function_pac_enabled_p (void) +{ + return aarch_ra_sign_scope == AARCH_FUNCTION_ALL + || (aarch_ra_sign_scope == AARCH_FUNCTION_NON_LEAF + && !crtl->is_leaf); +} + /* Implement TARGET_SCHED_CAN_SPECULATE_INSN. Return true if INSN can be scheduled for speculative execution. Reject the long-running division and square-root instructions. */ diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md index 60468f6182c..92269a7819a 100644 --- a/gcc/config/arm/arm.md +++ b/gcc/config/arm/arm.md @@ -11518,7 +11518,7 @@ arm_expand_prologue (); else thumb1_expand_prologue (); - DONE; + DONE; " ) @@ -12890,6 +12890,29 @@ (set_attr "length" "8")] ) +(define_insn "pac_nop" + [(set (reg:SI IP_REGNUM) + (unspec:SI [(reg:SI SP_REGNUM) (reg:SI LR_REGNUM)] + UNSPEC_PAC_NOP))] + "arm_arch7 && arm_arch_cmse" + "pac\t%|ip, %|lr, %|sp" + [(set_attr "length" "4")]) + +(define_insn "pacbti_nop" + [(set (reg:SI IP_REGNUM) + (unspec:SI [(reg:SI SP_REGNUM) (reg:SI LR_REGNUM)] + UNSPEC_PACBTI_NOP))] + "arm_arch7 && arm_arch_cmse" + "pacbti\t%|ip, %|lr, %|sp" + [(set_attr "length" "4")]) + +(define_insn "aut_nop" + [(unspec:SI [(reg:SI IP_REGNUM) (reg:SI SP_REGNUM) (reg:SI LR_REGNUM)] + UNSPEC_AUT_NOP)] + "arm_arch7 && arm_arch_cmse" + "aut\t%|ip, %|lr, %|sp" + [(set_attr "length" "4")]) + ;; Vector bits common to IWMMXT, Neon and MVE (include "vec-common.md") ;; Load the Intel Wireless Multimedia Extension patterns diff --git a/gcc/config/arm/unspecs.md b/gcc/config/arm/unspecs.md index 7748e784379..dbe243a03f6 100644 --- a/gcc/config/arm/unspecs.md +++ b/gcc/config/arm/unspecs.md @@ -159,6 +159,9 @@ UNSPEC_VCDE ; Custom Datapath Extension instruction. UNSPEC_VCDEA ; Custom Datapath Extension instruction. UNSPEC_DLS ; Used for DLS (Do Loop Start), Armv8.1-M Mainline instruction + UNSPEC_PAC_NOP ; Represents PAC signing LR + UNSPEC_PACBTI_NOP ; Represents PAC signing LR + valid landing pad + UNSPEC_AUT_NOP ; Represents PAC verifying LR ]) diff --git a/gcc/testsuite/gcc.target/arm/pac-1.c b/gcc/testsuite/gcc.target/arm/pac-1.c new file mode 100644 index 00000000000..6cd64dbd014 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac-1.c @@ -0,0 +1,12 @@ +/* Testing return address signing. */ +/* { dg-do run } */ +/* { dg-require-effective-target mbranch_protection_ok } */ +/* { dg-require-effective-target arm_pacbti_hw } */ +/* { dg-options "-march=armv8.1-m.main+pacbti+fp -mbranch-protection=pac-ret+leaf -mthumb -mfloat-abi=hard --save-temps -O0" } */ + +#include "pac.h" + +/* { dg-final { scan-assembler-times "pac\tip, lr, sp" 2 } } */ +/* { dg-final { scan-assembler-times "aut\tip, lr, sp" 2 } } */ +/* { dg-final { scan-assembler-not "\tbti" } } */ + diff --git a/gcc/testsuite/gcc.target/arm/pac-2.c b/gcc/testsuite/gcc.target/arm/pac-2.c new file mode 100644 index 00000000000..945ce938592 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac-2.c @@ -0,0 +1,11 @@ +/* Testing return address signing. */ +/* { dg-do run } */ +/* { dg-require-effective-target mbranch_protection_ok } */ +/* { dg-require-effective-target arm_pacbti_hw } */ +/* { dg-options "-march=armv8.1-m.main+pacbti+fp -mbranch-protection=pac-ret -mthumb -mfloat-abi=hard --save-temps -O0" } */ + +#include "pac.h" + +/* { dg-final { scan-assembler "pac\tip, lr, sp" } } */ +/* { dg-final { scan-assembler "aut\tip, lr, sp" } } */ +/* { dg-final { scan-assembler-not "\tbti" } } */ diff --git a/gcc/testsuite/gcc.target/arm/pac-3.c b/gcc/testsuite/gcc.target/arm/pac-3.c new file mode 100644 index 00000000000..47e290a5840 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac-3.c @@ -0,0 +1,11 @@ +/* Testing return address signing. */ +/* { dg-do run } */ +/* { dg-require-effective-target mbranch_protection_ok } */ +/* { dg-require-effective-target arm_pacbti_hw } */ +/* { dg-options "-march=armv8.1-m.main+pacbti+fp -mbranch-protection=bti+pac-ret+leaf -mthumb -mfloat-abi=hard --save-temps -O2" } */ + +#include "pac.h" + +/* { dg-final { scan-assembler-times "pacbti\tip, lr, sp" 2 } } */ +/* { dg-final { scan-assembler-times "aut\tip, lr, sp" 2 } } */ +/* { dg-final { scan-assembler-not "\tbti" } } */ diff --git a/gcc/testsuite/gcc.target/arm/pac-4.c b/gcc/testsuite/gcc.target/arm/pac-4.c new file mode 100644 index 00000000000..cf915cdba50 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac-4.c @@ -0,0 +1,10 @@ +/* Testing return address signing. */ +/* { dg-do compile } */ +/* { dg-require-effective-target mbranch_protection_ok } */ +/* { dg-options "-march=armv8.1-m.main+pacbti+fp -mthumb -mfloat-abi=hard --save-temps -O2" } */ + +#include "pac.h" + +/* { dg-final { scan-assembler-not "\tbti\t" } } */ +/* { dg-final { scan-assembler-not "\tpac\t" } } */ +/* { dg-final { scan-assembler-not "\tpacbti\t" } } */ diff --git a/gcc/testsuite/gcc.target/arm/pac-5.c b/gcc/testsuite/gcc.target/arm/pac-5.c new file mode 100644 index 00000000000..c70087eb6b6 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac-5.c @@ -0,0 +1,28 @@ +/* Testing return address signing. */ +/* { dg-do run } */ +/* { dg-require-effective-target mbranch_protection_ok } */ +/* { dg-require-effective-target arm_pacbti_hw } */ +/* { dg-options "-march=armv8.1-m.main+pacbti+fp -mbranch-protection=pac-ret+leaf -mthumb -mfloat-abi=hard --save-temps -O0" } */ + +#include + +int +__attribute__((noinline)) +foo1 (int a, int b) +{ + int square (int z) { return z * z; } + return square (a) + square (b); +} + +int +main (void) +{ + if (foo1 (1, 2) != 5) + abort (); + + return 0; +} + +/* { dg-final { scan-assembler-times "pac\tip, lr, sp" 3 } } */ +/* { dg-final { scan-assembler-times "aut\tip, lr, sp" 3 } } */ +/* { dg-final { scan-assembler-not "\tbti" } } */ diff --git a/gcc/testsuite/gcc.target/arm/pac-6.c b/gcc/testsuite/gcc.target/arm/pac-6.c new file mode 100644 index 00000000000..c5329f0ef48 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac-6.c @@ -0,0 +1,18 @@ +/* Check that GCC does .save and .cfi_offset directives with RA_AUTH_CODE pseudo hard-register. */ +/* { dg-do compile } */ +/* { dg-require-effective-target mbranch_protection_ok } */ +/* { dg-options "-march=armv8.1-m.main+fp -mbranch-protection=pac-ret+leaf -mthumb --save-temps -O0 -g" } */ + +int i; + +void foo (int); + +int bar() +{ + foo (i); + return 0; +} + +/* { dg-final { scan-assembler "pac\tip, lr, sp" } } */ +/* { dg-final { scan-assembler "aut\tip, lr, sp" } } */ +/* { dg-final { scan-assembler-not "bti" } } */ diff --git a/gcc/testsuite/gcc.target/arm/pac-7.c b/gcc/testsuite/gcc.target/arm/pac-7.c new file mode 100644 index 00000000000..cdaebca5cfa --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac-7.c @@ -0,0 +1,32 @@ +/* Testing return address signing. */ +/* { dg-do run } */ +/* { dg-require-effective-target mbranch_protection_ok } */ +/* { dg-require-effective-target arm_pacbti_hw } */ +/* { dg-options "-march=armv8.1-m.main+pacbti+fp -mbranch-protection=pac-ret+leaf -mthumb -mfloat-abi=hard --save-temps -O0" } */ + +#include + +int +__attribute__((noinline)) +foo1 (int a, int b) +{ + int x = 4; + int foo2 (int a, int b) + { + return a + b + x; + } + return foo2 (a, b); +} + +int +main (void) +{ + if (foo1 (1, 2) != 7) + abort (); + + return 0; +} + +/* { dg-final { scan-assembler-times "pac\tip, lr, sp" 3 } } */ +/* { dg-final { scan-assembler-times "aut\tip, lr, sp" 3 } } */ +/* { dg-final { scan-assembler-not "\tbti" } } */ diff --git a/gcc/testsuite/gcc.target/arm/pac-8.c b/gcc/testsuite/gcc.target/arm/pac-8.c new file mode 100644 index 00000000000..3f37dcfa5c8 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac-8.c @@ -0,0 +1,34 @@ +/* Testing return address signing. */ +/* { dg-do run } */ +/* { dg-require-effective-target mbranch_protection_ok } */ +/* { dg-require-effective-target arm_pacbti_hw } */ +/* { dg-options "-march=armv8.1-m.main+pacbti+fp -mbranch-protection=pac-ret+leaf -mthumb -mfloat-abi=hard --save-temps -O0" } */ + +#include +#include + +int acc (int n, ...) +{ + int sum = 0; + va_list ptr; + + va_start (ptr, n); + + for (int i = 0; i < n; i++) + sum += va_arg (ptr, int); + va_end (ptr); + + return sum; +} + +int main() +{ + if (acc (3, 1, 2, 3) != 6) + abort (); + + return 0; +} + +/* { dg-final { scan-assembler-times "pac\tip, lr, sp" 2 } } */ +/* { dg-final { scan-assembler-times "aut\tip, lr, sp" 2 } } */ +/* { dg-final { scan-assembler-not "\tbti" } } */ diff --git a/gcc/testsuite/gcc.target/arm/pac.h b/gcc/testsuite/gcc.target/arm/pac.h new file mode 100644 index 00000000000..7355e6b2954 --- /dev/null +++ b/gcc/testsuite/gcc.target/arm/pac.h @@ -0,0 +1,17 @@ +#include + +int +__attribute__((noinline)) +foo1 (int a, int b) +{ + return a + b; +} + +int +main (void) +{ + if (foo1 (1, 2) != 3) + abort (); + + return 0; +}