From: Alexandre Ghiti <alexandre.ghiti@canonical.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
linux-riscv@lists.infradead.org
Cc: Anup Patel <anup@brainfault.org>, Alexandre Ghiti <alex@ghiti.fr>
Subject: [PATCH v7 2/3] powerpc: Move script to check relocations at compile time in scripts/
Date: Sat, 9 Oct 2021 19:12:58 +0200 [thread overview]
Message-ID: <20211009171259.2515351-3-alexandre.ghiti@canonical.com> (raw)
In-Reply-To: <20211009171259.2515351-1-alexandre.ghiti@canonical.com>
From: Alexandre Ghiti <alex@ghiti.fr>
Relocating kernel at runtime is done very early in the boot process, so
it is not convenient to check for relocations there and react in case a
relocation was not expected.
Powerpc architecture has a script that allows to check at compile time
for such unexpected relocations: extract the common logic to scripts/
so that other architectures can take advantage of it.
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Anup Patel <anup@brainfault.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
---
arch/powerpc/tools/relocs_check.sh | 18 ++----------------
scripts/relocs_check.sh | 20 ++++++++++++++++++++
2 files changed, 22 insertions(+), 16 deletions(-)
create mode 100755 scripts/relocs_check.sh
diff --git a/arch/powerpc/tools/relocs_check.sh b/arch/powerpc/tools/relocs_check.sh
index 014e00e74d2b..e367895941ae 100755
--- a/arch/powerpc/tools/relocs_check.sh
+++ b/arch/powerpc/tools/relocs_check.sh
@@ -15,21 +15,8 @@ if [ $# -lt 3 ]; then
exit 1
fi
-# Have Kbuild supply the path to objdump and nm so we handle cross compilation.
-objdump="$1"
-nm="$2"
-vmlinux="$3"
-
-# Remove from the bad relocations those that match an undefined weak symbol
-# which will result in an absolute relocation to 0.
-# Weak unresolved symbols are of that form in nm output:
-# " w _binary__btf_vmlinux_bin_end"
-undef_weak_symbols=$($nm "$vmlinux" | awk '$1 ~ /w/ { print $2 }')
-
bad_relocs=$(
-$objdump -R "$vmlinux" |
- # Only look at relocation lines.
- grep -E '\<R_' |
+${srctree}/scripts/relocs_check.sh "$@" |
# These relocations are okay
# On PPC64:
# R_PPC64_RELATIVE, R_PPC64_NONE
@@ -43,8 +30,7 @@ R_PPC_ADDR16_LO
R_PPC_ADDR16_HI
R_PPC_ADDR16_HA
R_PPC_RELATIVE
-R_PPC_NONE' |
- ([ "$undef_weak_symbols" ] && grep -F -w -v "$undef_weak_symbols" || cat)
+R_PPC_NONE'
)
if [ -z "$bad_relocs" ]; then
diff --git a/scripts/relocs_check.sh b/scripts/relocs_check.sh
new file mode 100755
index 000000000000..137c660499f3
--- /dev/null
+++ b/scripts/relocs_check.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Get a list of all the relocations, remove from it the relocations
+# that are known to be legitimate and return this list to arch specific
+# script that will look for suspicious relocations.
+
+objdump="$1"
+nm="$2"
+vmlinux="$3"
+
+# Remove from the possible bad relocations those that match an undefined
+# weak symbol which will result in an absolute relocation to 0.
+# Weak unresolved symbols are of that form in nm output:
+# " w _binary__btf_vmlinux_bin_end"
+undef_weak_symbols=$($nm "$vmlinux" | awk '$1 ~ /w/ { print $2 }')
+
+$objdump -R "$vmlinux" |
+ grep -E '\<R_' |
+ ([ "$undef_weak_symbols" ] && grep -F -w -v "$undef_weak_symbols" || cat)
--
2.30.2
next prev parent reply other threads:[~2021-10-09 22:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-09 17:12 [PATCH v7 0/3] Introduce 64b relocatable kernel Alexandre Ghiti
2021-10-09 17:12 ` [PATCH v7 1/3] riscv: Introduce CONFIG_RELOCATABLE Alexandre Ghiti
2021-10-09 17:20 ` Alexandre ghiti
2021-10-26 21:29 ` Palmer Dabbelt
2021-10-27 5:04 ` Alexandre ghiti
2021-12-06 9:44 ` Alexandre ghiti
2022-01-10 8:05 ` Alexandre ghiti
2022-02-18 10:47 ` Alexandre Ghiti
2021-10-09 17:12 ` Alexandre Ghiti [this message]
2021-10-09 17:12 ` [PATCH v7 3/3] riscv: Check relocations at compile time Alexandre Ghiti
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