Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Tue, 25 Feb 2020 09:39:26 -0800
From: Sami Tolvanen <>
To: Will Deacon <>, Catalin Marinas <>, 
	James Morse <>, Steven Rostedt <>, 
	Masami Hiramatsu <>, Ard Biesheuvel <>, 
	Mark Rutland <>
Cc: Dave Martin <>, Kees Cook <>, 
	Laura Abbott <>, Marc Zyngier <>, 
	Nick Desaulniers <>, Jann Horn <>, 
	Miguel Ojeda <>, 
	Masahiro Yamada <>,,,,, Sami Tolvanen <>
Subject: [PATCH v9 05/12] arm64: reserve x18 from general allocation with SCS

Reserve the x18 register from general allocation when SCS is enabled,
because the compiler uses the register to store the current task's
shadow stack pointer. Note that all external kernel modules must also be
compiled with -ffixed-x18 if the kernel has SCS enabled.

Signed-off-by: Sami Tolvanen <>
Reviewed-by: Nick Desaulniers <>
Reviewed-by: Kees Cook <>
Acked-by: Will Deacon <>
 arch/arm64/Makefile | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index dca1a97751ab..ab26b448faa9 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -65,6 +65,10 @@ stack_protector_prepare: prepare0
+KBUILD_CFLAGS	+= -ffixed-x18
 KBUILD_CPPFLAGS	+= -mbig-endian

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.