[PATCH v4 mips-next 0/7] MIPS: vmlinux.lds.S sections fixes & cleanup

From: Alexander Lobakin <alobakin@pm.me>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Fangrui Song <maskray@google.com>,
	Huacai Chen <chenhuacai@kernel.org>,
	Pei Huang <huangpei@loongson.cn>,
	Jiaxun Yang <jiaxun.yang@flygoat.com>,
	Alexander Lobakin <alobakin@pm.me>,
	Sami Tolvanen <samitolvanen@google.com>,
	Ingo Molnar <mingo@kernel.org>,
	Ralf Baechle <ralf@linux-mips.org>,
	Corey Minyard <cminyard@mvista.com>,
	linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arch@vger.kernel.org, stable@vger.kernel.org,
	clang-built-linux@googlegroups.com
Subject: [PATCH v4 mips-next 0/7] MIPS: vmlinux.lds.S sections fixes & cleanup
Date: Thu, 07 Jan 2021 12:33:38 +0000	[thread overview]
Message-ID: <20210107123331.354075-1-alobakin@pm.me> (raw)

This series hunts the problems discovered after manual enabling of
ARCH_WANT_LD_ORPHAN_WARN. Notably:
 - adds the missing PAGE_ALIGNED_DATA() section affecting VDSO
   placement (marked for stable);
 - properly stops .eh_frame section generation.

Compile and runtime tested on MIPS32R2 CPS board with no issues
using two different toolkits:
 - Binutils 2.35.1, GCC 10.2.0;
 - LLVM stack 11.0.0.

Since v3 [2]:
 - fix the third patch as GNU stack emits .rel.dyn into VDSO for
   some reason if .cfi_sections is specified.

Since v2 [1]:
 - stop discarding .eh_frame and just prevent it from generating
   (Kees);
 - drop redundant sections assertions (Fangrui);
 - place GOT table in .text instead of asserting as it's not empty
   when building with LLVM (Nathan);
 - catch compound literals in generic definitions when building with
   LD_DEAD_CODE_DATA_ELIMINATION (Kees);
 - collect two Reviewed-bys (Kees).

Since v1 [0]:
 - catch .got entries too as LLD may produce it (Nathan);
 - check for unwanted sections to be zero-sized instead of
   discarding (Fangrui).

[0] https://lore.kernel.org/linux-mips/20210104121729.46981-1-alobakin@pm.me
[1] https://lore.kernel.org/linux-mips/20210106200713.31840-1-alobakin@pm.me
[2] https://lore.kernel.org/linux-mips/20210107115120.281008-1-alobakin@pm.me

Alexander Lobakin (7):
  MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() section
  MIPS: vmlinux.lds.S: add ".gnu.attributes" to DISCARDS
  MIPS: properly stop .eh_frame generation
  MIPS: vmlinux.lds.S: catch bad .rel.dyn at link time
  MIPS: vmlinux.lds.S: explicitly declare .got table
  vmlinux.lds.h: catch compound literals into data and BSS
  MIPS: select ARCH_WANT_LD_ORPHAN_WARN

 arch/mips/Kconfig                 |  1 +
 arch/mips/include/asm/asm.h       | 18 ++++++++++++++++++
 arch/mips/kernel/vmlinux.lds.S    | 15 ++++++++++++++-
 include/asm-generic/vmlinux.lds.h |  6 +++---
 4 files changed, 36 insertions(+), 4 deletions(-)

-- 
2.30.0