public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Stephen Rothwell <sfr@canb.auug.org.au>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Jessica Yu <jeyu@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 22/23] kbuild: fix CONFIG_TRIM_UNUSED_KSYMS build for ppc64
Date: Thu, 25 Feb 2021 10:53:53 +0100	[thread overview]
Message-ID: <20210225092517.578415148@linuxfoundation.org> (raw)
In-Reply-To: <20210225092516.531932232@linuxfoundation.org>

From: Masahiro Yamada <masahiroy@kernel.org>

[ Upstream commit 29500f15b54b63ad0ea60b58e85144262bd24df2 ]

Stephen Rothwell reported a build error on ppc64 when
CONFIG_TRIM_UNUSED_KSYMS is enabled.

Jessica Yu pointed out the cause of the error with the reference to the
ppc64 ELF ABI:
  "Symbol names with a dot (.) prefix are reserved for holding entry
   point addresses. The value of a symbol named ".FN", if it exists,
   is the entry point of the function "FN".

As it turned out, CONFIG_TRIM_UNUSED_KSYMS has never worked for ppc64,
but this issue has been unnoticed until recently because this option
depends on !UNUSED_SYMBOLS hence is disabled by all{mod,yes}config.
(Then, it was uncovered by another patch removing UNUSED_SYMBOLS.)

Removing the dot prefix in scripts/gen_autoksyms.sh fixes the issue.
Please note it must be done before 'sort -u' because modules have
both ._mcount and _mcount undefined when CONFIG_FUNCTION_TRACER=y.

Link: https://lore.kernel.org/lkml/20210209210843.3af66662@canb.auug.org.au/
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 scripts/gen_autoksyms.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh
index 16c0b2ddaa4c9..d54dfba15bf25 100755
--- a/scripts/gen_autoksyms.sh
+++ b/scripts/gen_autoksyms.sh
@@ -43,6 +43,9 @@ EOT
 sed 's/ko$/mod/' $modlist |
 xargs -n1 sed -n -e '2{s/ /\n/g;/^$/!p;}' -- |
 cat - "$ksym_wl" |
+# Remove the dot prefix for ppc64; symbol names with a dot (.) hold entry
+# point addresses.
+sed -e 's/^\.//' |
 sort -u |
 sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$output_file"
 
-- 
2.27.0




  parent reply	other threads:[~2021-02-25 10:14 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-25  9:53 [PATCH 5.10 00/23] 5.10.19-rc1 review Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 01/23] bpf: Fix truncation handling for mod32 dst reg wrt zero Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 02/23] HID: make arrays usage and value to be the same Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 03/23] RDMA: Lift ibdev_to_node from rds to common code Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 04/23] nvme-rdma: Use ibdev_to_node instead of dereferencing ->dma_device Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 05/23] USB: quirks: sort quirk entries Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 06/23] usb: quirks: add quirk to start video capture on ELMO L-12F document camera reliable Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 07/23] ceph: downgrade warning from mdsmap decode to debug Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 08/23] ntfs: check for valid standard information attribute Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 09/23] Bluetooth: btusb: Some Qualcomm Bluetooth adapters stop working Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 10/23] arm64: tegra: Add power-domain for Tegra210 HDA Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 11/23] hwmon: (dell-smm) Add XPS 15 L502X to fan control blacklist Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 12/23] KVM: x86: Zap the oldest MMU pages, not the newest Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 13/23] mm: unexport follow_pte_pmd Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 14/23] mm: simplify follow_pte{,pmd} Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 15/23] KVM: do not assume PTE is writable after follow_pfn Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 16/23] mm: provide a saner PTE walking API for modules Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 17/23] KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 18/23] drm/xlnx: fix kmemleak by sending vblank_event in atomic_disable Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 19/23] NET: usb: qmi_wwan: Adding support for Cinterion MV31 Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 20/23] cxgb4: Add new T6 PCI device id 0x6092 Greg Kroah-Hartman
2021-02-25  9:53 ` [PATCH 5.10 21/23] cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath Greg Kroah-Hartman
2021-02-25  9:53 ` Greg Kroah-Hartman [this message]
2021-02-25  9:53 ` [PATCH 5.10 23/23] scripts/recordmcount.pl: support big endian for ARCH sh Greg Kroah-Hartman
2021-02-25 19:52 ` [PATCH 5.10 00/23] 5.10.19-rc1 review Guenter Roeck
2021-02-25 19:54 ` Pavel Machek
2021-02-25 21:35 ` Florian Fainelli
2021-02-26  2:24 ` Shuah Khan
2021-02-26  3:41 ` Ross Schmidt
2021-02-26  6:44 ` Hanjun Guo
2021-02-27  1:47   ` Hanjun Guo
2021-02-26  6:57 ` Naresh Kamboju

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=20210225092517.578415148@linuxfoundation.org \
    --to=gregkh@linuxfoundation.org \
    --cc=jeyu@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=masahiroy@kernel.org \
    --cc=sashal@kernel.org \
    --cc=sfr@canb.auug.org.au \
    --cc=stable@vger.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