arm64: Support BTI checking in most of the kernel

LLD has the -zbti-report=error argument to check if the BTI note is
present when linking. To allow for this to be used when linking the
kernel and modules:
 - Add the BTI note to the remaining assembly files
 - Mark ptrauth.c as protected by BTI
 - Disable -zbti-report for vmm hypervisor switching code as it's not
   used there.

The linux64 module doesn't build with the flag as it includes vdso code
that doesn't include the note.

Reviewed by:	imp, kib, emaste
Sponsored by:	Arm Ltd
Differential Revision:	https://reviews.freebsd.org/D45466

sys/arm64/arm64/bus_space_asm.S

@@ -25,7 +25,9 @@
  *
  */
 
+#include <sys/elf_common.h>
 #include <machine/asm.h>
+
 ENTRY(generic_bs_r_1)
 	ldrb	w0, [x1, x2]
 	ret
@@ -475,3 +477,5 @@ generic_bs_poke_8f:
 	mov	x0, #0
 	ret
 END(generic_bs_poke_8)
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/copyinout.S

@@ -27,9 +27,10 @@
  *
  */
 
-#include <machine/asm.h>
+#include <sys/elf_common.h>
 #include <sys/errno.h>
 
+#include <machine/asm.h>
 #include <machine/param.h>
 #include <machine/vmparam.h>
 
@@ -220,3 +221,5 @@ ending:
 	mov	x0, xzr		/* return 0 */
 	ret
 	.size	copycommon, . - copycommon
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/cpufunc_asm.S

@@ -29,7 +29,9 @@
  *
  */
 
+#include <sys/elf_common.h>
 #include <sys/errno.h>
+
 #include <machine/asm.h>
 #include <machine/param.h>
 
@@ -190,3 +192,5 @@ ENTRY(cache_maint_fault)
 	mov	x0, #EFAULT
 	ret
 END(cache_maint_fault)
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/exception.S

@@ -25,6 +25,8 @@
  *
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 #include <machine/armreg.h>
 #include "assym.inc"
@@ -324,3 +326,4 @@ exception_vectors:
 	vempty 0		/* FIQ 32-bit EL0 */
 	vector el0_serror 0	/* Error 32-bit EL0 */
 
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/hyp_stub.S

@@ -24,6 +24,8 @@
  * SUCH DAMAGE.
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 
 .macro vempty
@@ -63,3 +65,5 @@ hyp_stub_vectors:
 	vempty			/* IRQ 32-bit EL1 */
 	vempty			/* FIQ 32-bit EL1 */
 	vempty			/* SError 32-bit EL1 */
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/locore.S

@@ -26,6 +26,7 @@
 
 #include "assym.inc"
 #include "opt_kstack_pages.h"
+#include <sys/elf_common.h>
 #include <sys/syscall.h>
 #include <machine/asm.h>
 #include <machine/armreg.h>
@@ -1006,3 +1007,5 @@ aarch32_esigcode:
 	.global sz_aarch32_sigcode
 sz_aarch32_sigcode:
 	.quad aarch32_esigcode - aarch32_sigcode
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/memcmp.S

@@ -9,6 +9,8 @@
  * ARMv8-a, AArch64, unaligned accesses.
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 
 #define L(l) .L ## l
@@ -134,3 +136,4 @@ L(byte_loop):
 
 END (memcmp)
 
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/memcpy.S

@@ -11,6 +11,8 @@
  *
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 
 #define L(l) .L ## l
@@ -240,3 +242,4 @@ L(copy64_from_start):
 END(memcpy)
 EEND(memmove)
 
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/memset.S

@@ -31,6 +31,8 @@
  *
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 
 #define dstin		x0
@@ -195,3 +197,5 @@ ENTRY(memset)
 	b.ne	.Ltail_maybe_long
 	ret
 END(memset)
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/sigtramp.S

@@ -27,6 +27,7 @@
  */
 
 #include "assym.inc"
+#include <sys/elf_common.h>
 #include <sys/syscall.h>
 #include <machine/asm.h>
 
@@ -57,3 +58,5 @@ esigcode:
 	.global	szsigcode
 szsigcode:
 	.quad	esigcode - sigcode
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/strcmp.S

@@ -12,6 +12,8 @@
  * MTE compatible.
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 
 #define L(l) .L ## l
@@ -187,3 +189,4 @@ L(done):
 
 END (strcmp)
 
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/strncmp.S

@@ -11,6 +11,8 @@
  * MTE compatible.
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 
 #define L(l) .L ## l
@@ -305,3 +307,4 @@ L(ret0):
 	ret
 END(strncmp)
 
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/support.S

@@ -29,6 +29,8 @@
  *
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 #include <machine/setjmp.h>
 #include <machine/param.h>
@@ -387,3 +389,5 @@ ENTRY(pagezero_cache)
 	ret
 
 END(pagezero_cache)
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/arm64/swtch.S

@@ -33,6 +33,8 @@
 #include "opt_kstack_pages.h"
 #include "opt_sched.h"
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
 #include <machine/armreg.h>
 .macro clear_step_flag pcbflags, tmp
@@ -277,3 +279,4 @@ ENTRY(savectx)
 	ret
 END(savectx)
 
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/vmm/vmm_call.S

@@ -28,6 +28,7 @@
  * SUCH DAMAGE.
  */
 
+#include <sys/elf_common.h>
 
 #include <machine/asm.h>
 
@@ -37,3 +38,5 @@ ENTRY(vmm_call_hyp)
 	hvc	#0
 	ret
 END(vmm_call_hyp)
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/arm64/vmm/vmm_hyp_el2.S

@@ -28,6 +28,9 @@
  * SUCH DAMAGE.
  */
 
+#include <sys/elf_common.h>
+
+#include <machine/asm.h>
 #include <machine/param.h>
 
 	.section .rodata
@@ -37,3 +40,5 @@ vmm_hyp_code:
 	.incbin "vmm_hyp_blob.bin"
 	.globl vmm_hyp_code_end
 vmm_hyp_code_end:
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/cddl/dev/dtrace/aarch64/dtrace_asm.S

@@ -29,6 +29,7 @@
 
 #include <sys/cpuvar_defs.h>
 #include <sys/dtrace.h>
+#include <sys/elf_common.h>
 
 #include <machine/armreg.h>
 #include <machine/asm.h>
@@ -172,3 +173,5 @@ ENTRY(dtrace_casptr)
 2:	mov	x0, x3		/* Return the value loaded from target */
 	RET
 END(dtrace_casptr)
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/conf/files.arm64

@@ -65,7 +65,7 @@ arm64/arm64/nexus.c				standard
 arm64/arm64/ofw_machdep.c			optional fdt
 arm64/arm64/pl031_rtc.c				optional fdt pl031
 arm64/arm64/ptrauth.c				standard \
-	compile-with	"${NORMAL_C:N-mbranch-protection*}"
+	compile-with	"${NORMAL_C:N-mbranch-protection*} -mbranch-protection=bti"
 arm64/arm64/pmap.c				standard
 arm64/arm64/ptrace_machdep.c			standard
 arm64/arm64/sigtramp.S				standard

sys/dev/psci/smccc_arm64.S

@@ -30,7 +30,10 @@
  * SUCH DAMAGE.
  */
 
+#include <sys/elf_common.h>
+
 #include <machine/asm.h>
+
 .macro arm_smccc_1_0	insn
 ENTRY(arm_smccc_\insn)
 	\insn	#0
@@ -84,3 +87,5 @@ END(arm_smccc_1_2_\insn)
  */
 arm_smccc_1_2	hvc
 arm_smccc_1_2	smc
+
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)

sys/kern/firmw.S

@@ -45,3 +45,9 @@ FIRMW_START(FIRMW_SYMBOL):
 	.type	FIRMW_END(FIRMW_SYMBOL), %object
 FIRMW_END(FIRMW_SYMBOL):
 	.size	FIRMW_END(FIRMW_SYMBOL), . - FIRMW_END(FIRMW_SYMBOL)
+
+#if defined(__aarch64__)
+#include <machine/asm.h>
+#include <sys/elf_common.h>
+GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL)
+#endif

sys/modules/vmm/Makefile

@@ -50,7 +50,7 @@ vmm_hyp.o: vmm_hyp.c
 
 vmm_hyp_blob.elf.full:	vmm_hyp_exception.o vmm_hyp.o
 	${LD} -m ${LD_EMULATION} -Bdynamic -T ${SYSDIR}/conf/ldscript.arm64 \
-	    ${_LDFLAGS} --no-warn-mismatch --warn-common --export-dynamic \
+	    ${_LDFLAGS:N-zbti-report*} --no-warn-mismatch --warn-common --export-dynamic \
 	    --dynamic-linker /red/herring -X -o ${.TARGET} ${.ALLSRC} \
 	    --defsym=_start='0x0' --defsym=text_start='0x0'