linux-kernel - [RFC PATCH 02/12] riscv: add landing pad for asm routines.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon,  8 Apr 2024 23:10:33 -0700
From: Deepak Gupta <debug@...osinc.com>
To: linux-riscv@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	llvm@...ts.linux.dev
Cc: paul.walmsley@...ive.com,
	palmer@...belt.com,
	aou@...s.berkeley.edu,
	nathan@...nel.org,
	ndesaulniers@...gle.com,
	morbo@...gle.com,
	justinstitt@...gle.com,
	andy.chiu@...ive.com,
	debug@...osinc.com,
	hankuan.chen@...ive.com,
	guoren@...nel.org,
	greentime.hu@...ive.com,
	samitolvanen@...gle.com,
	cleger@...osinc.com,
	apatel@...tanamicro.com,
	ajones@...tanamicro.com,
	conor.dooley@...rochip.com,
	mchitale@...tanamicro.com,
	dbarboza@...tanamicro.com,
	waylingii@...il.com,
	sameo@...osinc.com,
	alexghiti@...osinc.com,
	akpm@...ux-foundation.org,
	shikemeng@...weicloud.com,
	rppt@...nel.org,
	charlie@...osinc.com,
	xiao.w.wang@...el.com,
	willy@...radead.org,
	jszhang@...nel.org,
	leobras@...hat.com,
	songshuaishuai@...ylab.org,
	haxel@....de,
	samuel.holland@...ive.com,
	namcaov@...il.com,
	bjorn@...osinc.com,
	cuiyunhui@...edance.com,
	wangkefeng.wang@...wei.com,
	falcon@...ylab.org,
	viro@...iv.linux.org.uk,
	bhe@...hat.com,
	chenjiahao16@...wei.com,
	hca@...ux.ibm.com,
	arnd@...db.de,
	kent.overstreet@...ux.dev,
	boqun.feng@...il.com,
	oleg@...hat.com,
	paulmck@...nel.org,
	broonie@...nel.org,
	rick.p.edgecombe@...el.com
Subject: [RFC PATCH 02/12] riscv: add landing pad for asm routines.

SYM_* macros are used to define assembly routines. In this patch series,
re-define those macros in risc-v arch specific include file to include
a landing pad instruction at the beginning. This is done only when the
compiler flag for landing pad is enabled (i.e. __riscv_zicfilp).

Signed-off-by: Deepak Gupta <debug@...osinc.com>
---
 arch/riscv/include/asm/linkage.h | 42 ++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/arch/riscv/include/asm/linkage.h b/arch/riscv/include/asm/linkage.h
index 9e88ba23cd2b..bb43ae7dadeb 100644
--- a/arch/riscv/include/asm/linkage.h
+++ b/arch/riscv/include/asm/linkage.h
@@ -6,7 +6,49 @@
 #ifndef _ASM_RISCV_LINKAGE_H
 #define _ASM_RISCV_LINKAGE_H
 
+#ifdef __ASSEMBLY__
+#include <asm/assembler.h>
+#endif
+
 #define __ALIGN		.balign 4
 #define __ALIGN_STR	".balign 4"
 
+#ifdef __riscv_zicfilp
+/*
+ * A landing pad instruction is needed at start of asm routines
+ * re-define macros for asm routines to have a landing pad at
+ * the beginning of function. Currently use label value of 0x1.
+ * Eventually, label should be calculated as a hash over function
+ * signature.
+ */
+#define SYM_FUNC_START(name)				\
+	SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)	\
+	lpad 0x1;
+
+#define SYM_FUNC_START_NOALIGN(name)			\
+	SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)	\
+	lpad 0x1;
+
+#define SYM_FUNC_START_LOCAL(name)			\
+	SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)	\
+	lpad 0x1;
+
+#define SYM_FUNC_START_LOCAL_NOALIGN(name)		\
+	SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)	\
+	lpad 0x1;
+
+#define SYM_FUNC_START_WEAK(name)			\
+	SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN)	\
+	lpad 0x1;
+
+#define SYM_FUNC_START_WEAK_NOALIGN(name)		\
+	SYM_START(name, SYM_L_WEAK, SYM_A_NONE)		\
+	lpad 0x1;
+
+#define SYM_TYPED_FUNC_START(name)				\
+	SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)	\
+	lpad 0x1;
+
+#endif
+
 #endif /* _ASM_RISCV_LINKAGE_H */
-- 
2.43.2