From 42b01a553a56d9bc7c75b700fd274f1ec4a3763f Mon Sep 17 00:00:00 2001
From: Vasily Gorbik <gor@linux.ibm.com>
Date: Sat, 29 Jan 2022 00:34:13 +0100
Subject: s390: always use the packed stack layout
-mpacked-stack option has been supported by both minimum
gcc and clang versions for a while. With commit e2bc3e91d91e
("scripts/min-tool-version.sh: Raise minimum clang version to 13.0.0
for s390") minimum clang version now also supports a combination
of flags -mpacked-stack -mbackchain -pg -mfentry and fulfills
all requirements to always enable the packed stack layout.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
arch/s390/Kconfig | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)
(limited to 'arch/s390/Kconfig')
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index be9f39fd06df..a492376d6e3f 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -155,7 +155,7 @@ config S390
select HAVE_DYNAMIC_FTRACE_WITH_ARGS
select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
select HAVE_DYNAMIC_FTRACE_WITH_REGS
- select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES
+ select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
select HAVE_EFFICIENT_UNALIGNED_ACCESS
select HAVE_FAST_GUP
select HAVE_FENTRY
@@ -656,20 +656,6 @@ config MAX_PHYSMEM_BITS
Increasing the number of bits also increases the kernel image size.
By default 46 bits (64TB) are supported.
-config PACK_STACK
- def_bool y
- prompt "Pack kernel stack"
- help
- This option enables the compiler option -mkernel-backchain if it
- is available. If the option is available the compiler supports
- the new stack layout which dramatically reduces the minimum stack
- frame size. With an old compiler a non-leaf function needs a
- minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
- -mkernel-backchain the minimum size drops to 16 byte on 31 bit
- and 24 byte on 64 bit.
-
- Say Y if you are unsure.
-
config CHECK_STACK
def_bool y
depends on !VMAP_STACK
--
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