From: Arnd Bergmann <arnd@arndb.de>
To: Nicolas Pitre <nico@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>
Subject: [PATCH 2/7] ARM: LTO: avoid THUMB2_KERNEL+LTO
Date: Tue, 20 Feb 2018 22:59:49 +0100 [thread overview]
Message-ID: <20180220215954.4092811-3-arnd@arndb.de> (raw)
In-Reply-To: <20180220215954.4092811-1-arnd@arndb.de>
Trying to build an LTO-Enabled kernel with Thumb2 instructions failed
horribly for me, with an endless output of things like
ccVnNycO.s:2665: Error: thumb conditional instruction should be in IT block -- `bxne lr'
ccVnNycO.s:7128: Error: thumb conditional instruction should be in IT block -- `strexeq r5,r2,[r3]'
ccVnNycO.s:7258: Error: thumb conditional instruction should be in IT block -- `strexeq lr,r0,[r3]'
ccVnNycO.s:17380: Error: thumb conditional instruction should be in IT block -- `strexeq r1,r2,[r6]'
ccVnNycO.s:19163: Error: thumb conditional instruction should be in IT block -- `strexeq r8,r6,[r3]'
ccVnNycO.s:22722: Error: thumb conditional instruction should be in IT block -- `strexeq r7,r1,[r0]'
ccVnNycO.s:24105: conditional infixes are deprecated in unified syntax
ccVnNycO.s:24105: Error: thumb conditional instruction should be in IT block -- `sbcccs r1,r1,r3'
ccVnNycO.s:24105: Error: thumb conditional instruction should be in IT block -- `movcc r3,#0'
ccVnNycO.s:24210: conditional infixes are deprecated in unified syntax
ccVnNycO.s:24210: Error: thumb conditional instruction should be in IT block -- `sbcccs r2,r2,r3'
ccVnNycO.s:24210: Error: thumb conditional instruction should be in IT block -- `movcc r3,#0'
I did not investigate this too much, disabling Thumb2 support when LTO is
set lets me build randconfig kernels.
Since ARM_SINGLE_ARMV7M is Thumb2-only, I have to disallow LTO for V7-M
targets.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/arm/Kconfig | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8ed0f664f86f..fbf2c3ab9a97 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -18,7 +18,7 @@ config ARM
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
select ARCH_SUPPORTS_ATOMIC_RMW
- select ARCH_SUPPORTS_LTO
+ select ARCH_SUPPORTS_LTO if !ARM_SINGLE_ARMV7M
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_WANT_IPC_PARSE_VERSION
@@ -1533,6 +1533,7 @@ config SCHED_HRTICK
config THUMB2_KERNEL
bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
+ depends on !LTO
default y if CPU_THUMBONLY
select ARM_UNWIND
help
--
2.9.0
next prev parent reply other threads:[~2018-02-20 22:00 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-20 21:59 [PATCH 0/7] ARM: hacks for link-time optimization Arnd Bergmann
2018-02-20 21:59 ` [PATCH 1/7] ARM: disallow combining XIP and LTO Arnd Bergmann
2018-02-21 3:01 ` Nicolas Pitre
2018-02-21 11:50 ` Arnd Bergmann
2018-02-21 15:13 ` Nicolas Pitre
2018-03-12 2:40 ` Nicolas Pitre
2018-03-12 13:52 ` Arnd Bergmann
2018-03-12 16:46 ` Arnd Bergmann
2018-03-12 17:00 ` Nicolas Pitre
2018-03-12 17:05 ` Nicolas Pitre
2018-03-12 17:07 ` Arnd Bergmann
2018-02-20 21:59 ` Arnd Bergmann [this message]
2018-02-21 3:12 ` [PATCH 2/7] ARM: LTO: avoid THUMB2_KERNEL+LTO Nicolas Pitre
2018-02-21 11:48 ` Arnd Bergmann
2018-03-07 18:30 ` Matthias Kaehlcke
2018-03-07 18:52 ` Nicolas Pitre
2018-02-20 21:59 ` [PATCH 3/7] [HACK] pass endianess flag to LTO linker Arnd Bergmann
2018-02-21 3:15 ` Nicolas Pitre
2018-02-21 9:44 ` Arnd Bergmann
2018-02-21 8:37 ` Ard Biesheuvel
2018-02-21 9:48 ` Arnd Bergmann
2018-02-21 10:09 ` Ard Biesheuvel
2018-02-21 13:00 ` Arnd Bergmann
2018-02-20 21:59 ` [PATCH 4/7] ARM: io-acorn: fix LTO linking without CONFIG_PRINTK Arnd Bergmann
2018-02-20 21:59 ` [PATCH 5/7] ARM: fix __inflate_kernel_data stack warning for LTO Arnd Bergmann
2018-02-21 3:26 ` Nicolas Pitre
2018-02-20 21:59 ` [PATCH 6/7] ARM: mark assembler-referenced symbols as __visible Arnd Bergmann
2018-02-20 21:59 ` [PATCH 7/7] efi: disable LTO for EFI stub Arnd Bergmann
2018-12-17 22:50 ` [PATCH 0/7] ARM: hacks for link-time optimization Peter Zijlstra
2018-12-18 0:08 ` Andi Kleen
2018-12-18 9:18 ` Peter Zijlstra
2018-12-18 10:00 ` Peter Zijlstra
2018-12-21 14:23 ` Paul E. McKenney
2018-12-21 17:20 ` Andi Kleen
2018-12-21 18:00 ` Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180220215954.4092811-3-arnd@arndb.de \
--to=arnd@arndb.de \
--cc=ak@linux.intel.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=nico@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).