From: Amit Daniel Kachhap <amit.kachhap@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Vincenzo Frascino <Vincenzo.Frascino@arm.com>,
linux-kernel@vger.kernel.org,
Amit Daniel Kachhap <amit.kachhap@arm.com>
Subject: [PATCH v2 2/2] arm64: Kconfig: ptrauth: Add binutils version check to fix mismatch
Date: Mon, 30 Mar 2020 17:11:39 +0530 [thread overview]
Message-ID: <1585568499-21585-2-git-send-email-amit.kachhap@arm.com> (raw)
In-Reply-To: <1585568499-21585-1-git-send-email-amit.kachhap@arm.com>
Recent addition of ARM64_PTR_AUTH exposed a mismatch issue with binutils.
9.1+ versions of gcc inserts a section note .note.gnu.property but this
can be used properly by binutils version greater than 2.33.1. If older
binutils are used then the following warnings are generated,
aarch64-linux-ld: warning: arch/arm64/kernel/vdso/vgettimeofday.o: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000
aarch64-linux-objdump: warning: arch/arm64/lib/csum.o: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000
aarch64-linux-nm: warning: .tmp_vmlinux1: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000
This patch enables ARM64_PTR_AUTH when gcc and binutils versions are
compatible with each other. Older gcc which do not insert such section
continue to work as before.
This scenario may not occur with clang as a recent commit 3b446c7d27ddd06
("arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH") masks
binutils version lesser then 2.34.
Reported-by: kbuild test robot <lkp@intel.com>
Suggested-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
Changes since v1[1]:
* Separated GCC and CLANG checks as suggested by Catalin.
* Added comments in Kconfig entry.
[1]: https://lkml.org/lkml/2020/3/26/626
arch/arm64/Kconfig | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e6712b6..4391a4f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1503,7 +1503,10 @@ config ARM64_PTR_AUTH
default y
depends on !KVM || ARM64_VHE
depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC
- depends on CC_IS_GCC || (CC_IS_CLANG && AS_HAS_CFI_NEGATE_RA_STATE)
+ # GCC 9.1 version inserts a section note .note.gnu.property for PAC
+ # which can be used properly by binutils version 2.33.1 and higher.
+ depends on !CC_IS_GCC || GCC_VERSION < 90100 || LD_VERSION >= 233010000
+ depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE
depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS)
help
Pointer authentication (part of the ARMv8.3 Extensions) provides
--
2.7.4
next prev parent reply other threads:[~2020-03-30 11:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-30 11:41 [PATCH v2 1/2] init/kconfig: Add LD_VERSION Kconfig Amit Daniel Kachhap
2020-03-30 11:41 ` Amit Daniel Kachhap [this message]
2020-04-01 12:28 ` [PATCH v2 2/2] arm64: Kconfig: ptrauth: Add binutils version check to fix mismatch Catalin Marinas
2020-05-04 7:11 ` [PATCH v2 1/2] init/kconfig: Add LD_VERSION Kconfig Geert Uytterhoeven
2020-05-04 8:06 ` Will Deacon
2020-05-05 13:51 ` Michael Ellerman
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=1585568499-21585-2-git-send-email-amit.kachhap@arm.com \
--to=amit.kachhap@arm.com \
--cc=Vincenzo.Frascino@arm.com \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=will@kernel.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).