From 4fd79b90c52396d70e0b1206ceb1a873a0ad2589 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 23 Dec 2020 06:49:04 -0800
Subject: [PATCH] liblzma: Enable Intel CET in x86 CRC assembly codes

When Intel CET is enabled, we need to include <cet.h> in assembly codes
to mark Intel CET support and add _CET_ENDBR to indirect jump targets.

Tested on Intel Tiger Lake under CET enabled Linux.
---
 src/liblzma/check/crc32_x86.S | 9 +++++++++
 src/liblzma/check/crc64_x86.S | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/liblzma/check/crc32_x86.S b/src/liblzma/check/crc32_x86.S
index 632c7b37..7814beca 100644
--- a/src/liblzma/check/crc32_x86.S
+++ b/src/liblzma/check/crc32_x86.S
@@ -51,6 +51,14 @@ init_table(void)
  * extern uint32_t lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc);
  */
 
+/* When Intel CET is enabled, include <cet.h> in assembly code to mark
+   Intel CET support.  */
+#ifdef __CET__
+# include <cet.h>
+#else
+# define _CET_ENDBR
+#endif
+
 /*
  * On some systems, the functions need to be prefixed. The prefix is
  * usually an underscore.
@@ -83,6 +91,7 @@ init_table(void)
 
 	ALIGN(4, 16)
 LZMA_CRC32:
+	_CET_ENDBR
 	/*
 	 * Register usage:
 	 * %eax crc
diff --git a/src/liblzma/check/crc64_x86.S b/src/liblzma/check/crc64_x86.S
index f5bb84b9..7ee08f64 100644
--- a/src/liblzma/check/crc64_x86.S
+++ b/src/liblzma/check/crc64_x86.S
@@ -41,6 +41,14 @@ init_table(void)
  * extern uint64_t lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc);
  */
 
+/* When Intel CET is enabled, include <cet.h> in assembly code to mark
+   Intel CET support.  */
+#ifdef __CET__
+# include <cet.h>
+#else
+# define _CET_ENDBR
+#endif
+
 /*
  * On some systems, the functions need to be prefixed. The prefix is
  * usually an underscore.
@@ -73,6 +81,7 @@ init_table(void)
 
 	ALIGN(4, 16)
 LZMA_CRC64:
+	_CET_ENDBR
 	/*
 	 * Register usage:
 	 * %eax crc LSB