Fix objtool: missing int3 after ret warning

Resolve straight-line speculation warnings reported by objtool
for x86_64 assembly on Linux when CONFIG_SLS is set.  See the
following LWN article for the complete details.

https://lwn.net/Articles/877845/

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #13528
Closes #13575

module/icp/asm-x86_64/aes/aes_aesni.S

@@ -208,7 +208,7 @@ _key_expansion_256a_local:
 	pxor	%xmm1, %xmm0
 	movups	%xmm0, (%rcx)
 	add	$0x10, %rcx
-	ret
+	RET
 	nop
 SET_SIZE(_key_expansion_128)
 SET_SIZE(_key_expansion_256a)
@@ -236,7 +236,7 @@ _key_expansion_192a_local:
 	shufps	$0b01001110, %xmm2, %xmm1
 	movups	%xmm1, 0x10(%rcx)
 	add	$0x20, %rcx
-	ret
+	RET
 SET_SIZE(_key_expansion_192a)
 
 
@@ -257,7 +257,7 @@ _key_expansion_192b_local:
 
 	movups	%xmm0, (%rcx)
 	add	$0x10, %rcx
-	ret
+	RET
 SET_SIZE(_key_expansion_192b)
 
 
@@ -271,7 +271,7 @@ _key_expansion_256b_local:
 	pxor	%xmm1, %xmm2
 	movups	%xmm2, (%rcx)
 	add	$0x10, %rcx
-	ret
+	RET
 SET_SIZE(_key_expansion_256b)
 
 
@@ -376,7 +376,7 @@ rijndael_key_setup_enc_intel_local:
 	mov	$14, %rax			// return # rounds = 14
 #endif
 	FRAME_END
-	ret
+	RET
 
 .align 4
 .Lenc_key192:
@@ -413,7 +413,7 @@ rijndael_key_setup_enc_intel_local:
 	mov	$12, %rax			// return # rounds = 12
 #endif
 	FRAME_END
-	ret
+	RET
 
 .align 4
 .Lenc_key128:
@@ -453,13 +453,13 @@ rijndael_key_setup_enc_intel_local:
 	mov	$10, %rax			// return # rounds = 10
 #endif
 	FRAME_END
-	ret
+	RET
 
 .Lenc_key_invalid_param:
 #ifdef	OPENSSL_INTERFACE
 	mov	$-1, %rax	// user key or AES key pointer is NULL
 	FRAME_END
-	ret
+	RET
 #else
 	/* FALLTHROUGH */
 #endif	/* OPENSSL_INTERFACE */
@@ -471,7 +471,7 @@ rijndael_key_setup_enc_intel_local:
 	xor	%rax, %rax	// a key pointer is NULL or invalid keysize
 #endif	/* OPENSSL_INTERFACE */
 	FRAME_END
-	ret
+	RET
 	SET_SIZE(rijndael_key_setup_enc_intel)
 
 
@@ -548,7 +548,7 @@ FRAME_BEGIN
 	// OpenSolaris: rax = # rounds (10, 12, or 14) or 0 for error
 	// OpenSSL: rax = 0 for OK, or non-zero for error
 	FRAME_END
-	ret
+	RET
 	SET_SIZE(rijndael_key_setup_dec_intel)
 
 
@@ -655,7 +655,7 @@ ENTRY_NP(aes_encrypt_intel)
 	aesenclast	 %KEY, %STATE		// last round
 	movups	%STATE, (%OUTP)			// output
 
-	ret
+	RET
 	SET_SIZE(aes_encrypt_intel)
 
 
@@ -738,7 +738,7 @@ ENTRY_NP(aes_decrypt_intel)
 	aesdeclast	%KEY, %STATE		// last round
 	movups	%STATE, (%OUTP)			// output
 
-	ret
+	RET
 	SET_SIZE(aes_decrypt_intel)
 
 #endif	/* lint || __lint */

module/icp/asm-x86_64/aes/aes_amd64.S

@@ -785,7 +785,7 @@ ENTRY_NP(aes_encrypt_amd64)
 	mov	2*8(%rsp), %rbp
 	mov	3*8(%rsp), %r12
 	add	$[4*8], %rsp
-	ret
+	RET
 
 	SET_SIZE(aes_encrypt_amd64)
 
@@ -896,7 +896,7 @@ ENTRY_NP(aes_decrypt_amd64)
 	mov	2*8(%rsp), %rbp
 	mov	3*8(%rsp), %r12
 	add	$[4*8], %rsp
-	ret
+	RET
 
 	SET_SIZE(aes_decrypt_amd64)
 #endif	/* lint || __lint */

module/icp/asm-x86_64/modes/aesni-gcm-x86_64.S

@@ -1201,7 +1201,7 @@ aesni_gcm_encrypt:
 .align	32
 clear_fpu_regs_avx:
 	vzeroall
-	ret
+	RET
 .size	clear_fpu_regs_avx,.-clear_fpu_regs_avx
 
 /*
@@ -1219,7 +1219,7 @@ gcm_xor_avx:
 	movdqu  (%rsi), %xmm1
 	pxor    %xmm1, %xmm0
 	movdqu  %xmm0, (%rsi)
-	ret
+	RET
 .size	gcm_xor_avx,.-gcm_xor_avx
 
 /*
@@ -1236,7 +1236,7 @@ atomic_toggle_boolean_nv:
 	jz	1f
 	movl	$1, %eax
 1:
-	ret
+	RET
 .size	atomic_toggle_boolean_nv,.-atomic_toggle_boolean_nv
 
 .align	64

module/icp/asm-x86_64/modes/gcm_pclmulqdq.S

@@ -244,7 +244,7 @@ ENTRY_NP(gcm_mul_pclmulqdq)
 	//
 	// Return
 	//
-	ret
+	RET
 	SET_SIZE(gcm_mul_pclmulqdq)
 
 #endif	/* lint || __lint */

module/icp/asm-x86_64/sha2/sha256_impl.S

@@ -2058,7 +2058,7 @@ ENTRY_NP(SHA256TransformBlocks)
 .cfi_adjust_cfa_offset -8
 .cfi_restore	%rbx
 
-	ret
+	RET
 .cfi_endproc
 SET_SIZE(SHA256TransformBlocks)
 

module/icp/asm-x86_64/sha2/sha512_impl.S

@@ -2059,7 +2059,7 @@ ENTRY_NP(SHA512TransformBlocks)
 .cfi_adjust_cfa_offset -8
 .cfi_restore	%rbx
 
-	ret
+	RET
 .cfi_endproc
 SET_SIZE(SHA512TransformBlocks)
 

module/icp/include/sys/ia32/asm_linkage.h

@@ -30,6 +30,12 @@
 #include <sys/stack.h>
 #include <sys/trap.h>
 
+#if defined(__linux__) && defined(CONFIG_SLS)
+#define	RET	ret; int3
+#else
+#define	RET	ret
+#endif
+
 #ifdef	__cplusplus
 extern "C" {
 #endif