From: H.J. Lu <hjl.tools@gmail.com>

Date: Wed, 23 Dec 2020 15:49:04 +0100 (06:49 -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 67f68a4..e3745e6 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 f5bb84b..7ee08f6 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

-- 

2.26.0