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authorSami Tolvanen <samitolvanen@google.com>2022-09-09 00:55:02 +0300
committerKees Cook <keescook@chromium.org>2022-09-26 20:13:15 +0300
commitccace936eec7b805e1ab9268a6d163a00047b3a9 (patch)
tree407c8ce8cb9f0b30332323db255d1107bedfea41
parentca7e10bff196f69a450b9072a7b757713d3bb2dd (diff)
downloadlinux-ccace936eec7b805e1ab9268a6d163a00047b3a9.tar.xz
x86: Add types to indirectly called assembly functions
With CONFIG_CFI_CLANG, assembly functions indirectly called from C code must be annotated with type identifiers to pass CFI checking. Define the __CFI_TYPE helper macro to match the compiler generated function preamble, and ensure SYM_TYPED_FUNC_START also emits ENDBR with IBT. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-21-samitolvanen@google.com
-rw-r--r--arch/x86/crypto/blowfish-x86_64-asm_64.S5
-rw-r--r--arch/x86/include/asm/linkage.h12
-rw-r--r--arch/x86/lib/memcpy_64.S3
3 files changed, 17 insertions, 3 deletions
diff --git a/arch/x86/crypto/blowfish-x86_64-asm_64.S b/arch/x86/crypto/blowfish-x86_64-asm_64.S
index 802d71582689..4a43e072d2d1 100644
--- a/arch/x86/crypto/blowfish-x86_64-asm_64.S
+++ b/arch/x86/crypto/blowfish-x86_64-asm_64.S
@@ -6,6 +6,7 @@
*/
#include <linux/linkage.h>
+#include <linux/cfi_types.h>
.file "blowfish-x86_64-asm.S"
.text
@@ -141,7 +142,7 @@ SYM_FUNC_START(__blowfish_enc_blk)
RET;
SYM_FUNC_END(__blowfish_enc_blk)
-SYM_FUNC_START(blowfish_dec_blk)
+SYM_TYPED_FUNC_START(blowfish_dec_blk)
/* input:
* %rdi: ctx
* %rsi: dst
@@ -332,7 +333,7 @@ SYM_FUNC_START(__blowfish_enc_blk_4way)
RET;
SYM_FUNC_END(__blowfish_enc_blk_4way)
-SYM_FUNC_START(blowfish_dec_blk_4way)
+SYM_TYPED_FUNC_START(blowfish_dec_blk_4way)
/* input:
* %rdi: ctx
* %rsi: dst
diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h
index 73ca20049835..f484d656d34e 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -43,6 +43,18 @@
#endif /* __ASSEMBLY__ */
+#define __CFI_TYPE(name) \
+ SYM_START(__cfi_##name, SYM_L_LOCAL, SYM_A_NONE) \
+ .fill 11, 1, 0x90 ASM_NL \
+ .byte 0xb8 ASM_NL \
+ .long __kcfi_typeid_##name ASM_NL \
+ SYM_FUNC_END(__cfi_##name)
+
+/* SYM_TYPED_FUNC_START -- use for indirectly called globals, w/ CFI type */
+#define SYM_TYPED_FUNC_START(name) \
+ SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) \
+ ENDBR
+
/* SYM_FUNC_START -- use for global functions */
#define SYM_FUNC_START(name) \
SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) \
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index d0d7b9bc6cad..dd8cd8831251 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -2,6 +2,7 @@
/* Copyright 2002 Andi Kleen */
#include <linux/linkage.h>
+#include <linux/cfi_types.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
#include <asm/alternative.h>
@@ -27,7 +28,7 @@
* Output:
* rax original destination
*/
-SYM_FUNC_START(__memcpy)
+SYM_TYPED_FUNC_START(__memcpy)
ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
"jmp memcpy_erms", X86_FEATURE_ERMS