linux-kernel - [PATCH v2] riscv module: remove (NOLOAD)

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Message-Id: <20220322012617.3517297-1-maskray@google.com>
Date:   Mon, 21 Mar 2022 18:26:17 -0700
From:   Fangrui Song <maskray@...gle.com>
To:     Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        linux-riscv@...ts.infradead.org
Cc:     Nathan Chancellor <nathan@...nel.org>,
        linux-kernel@...r.kernel.org, llvm@...ts.linux.dev,
        Fangrui Song <maskray@...gle.com>
Subject: [PATCH v2] riscv module: remove (NOLOAD)

On ELF, (NOLOAD) sets the section type to SHT_NOBITS[1]. It is conceptually
inappropriate for .plt, .got, and .got.plt sections which are always
SHT_PROGBITS.

In GNU ld, if PLT entries are needed, .plt will be SHT_PROGBITS anyway
and (NOLOAD) will be essentially ignored. In ld.lld, since
https://reviews.llvm.org/D118840 ("[ELF] Support (TYPE=<value>) to
customize the output section type"), ld.lld will report a `section type
mismatch` error (later changed to a warning). Just remove (NOLOAD) to
fix the warning.

[1] https://lld.llvm.org/ELF/linker_script.html As of today, "The
section should be marked as not loadable" on
https://sourceware.org/binutils/docs/ld/Output-Section-Type.html is
outdated for ELF.

Link: https://github.com/ClangBuiltLinux/linux/issues/1597
Fixes: ab1ef68e5401 ("RISC-V: Add sections of PLT and GOT for kernel module")
Reported-by: Nathan Chancellor <nathan@...nel.org>
Signed-off-by: Fangrui Song <maskray@...gle.com>
---
 arch/riscv/include/asm/module.lds.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/include/asm/module.lds.h b/arch/riscv/include/asm/module.lds.h
index 4254ff2ff049..1075beae1ac6 100644
--- a/arch/riscv/include/asm/module.lds.h
+++ b/arch/riscv/include/asm/module.lds.h
@@ -2,8 +2,8 @@
 /* Copyright (C) 2017 Andes Technology Corporation */
 #ifdef CONFIG_MODULE_SECTIONS
 SECTIONS {
-	.plt (NOLOAD) : { BYTE(0) }
-	.got (NOLOAD) : { BYTE(0) }
-	.got.plt (NOLOAD) : { BYTE(0) }
+	.plt : { BYTE(0) }
+	.got : { BYTE(0) }
+	.got.plt : { BYTE(0) }
 }
 #endif
-- 
2.35.1.894.gb6a874cedc-goog