From: Brian Gerst <brgerst@gmail.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Brian Gerst <brgerst@gmail.com>
Subject: [PATCH v2 0/6] x86-64: Stack protector and percpu improvements
Date: Tue, 30 Nov 2021 15:55:43 -0500 [thread overview]
Message-ID: <20211130205549.116673-1-brgerst@gmail.com> (raw)
Currently, x86-64 uses an unusual per-cpu layout, where the percpu section
is linked at absolute address 0. The reason behind this is that older GCC
versions placed the stack protector (if enabled) at a fixed offset from the
GS segment base. Since the GS segement is also used for percpu variables,
this forced the current layout.
GCC since version 8.1 supports a configurable location for the stack
protector value, which allows removal of the restriction on how the percpu
section is linked.
Changes from v1:
- Remove fixed location stack protector support
Brian Gerst (6):
x86: Remove stack protector test scripts
x86-64: Convert stack protector to normal percpu variable
x86-64: Use relative per-cpu offsets
x86-64: Remove inverse relocations
kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU
percpu: Remove PER_CPU_FIRST_SECTION
arch/x86/Kconfig | 7 +-
arch/x86/Makefile | 19 +--
arch/x86/boot/compressed/misc.c | 14 +--
arch/x86/entry/entry_64.S | 2 +-
arch/x86/include/asm/percpu.h | 22 ----
arch/x86/include/asm/processor.h | 25 +---
arch/x86/include/asm/stackprotector.h | 36 ++----
arch/x86/kernel/asm-offsets_64.c | 6 -
arch/x86/kernel/cpu/common.c | 8 +-
arch/x86/kernel/head_64.S | 10 +-
arch/x86/kernel/irq_64.c | 1 -
arch/x86/kernel/setup_percpu.c | 12 +-
arch/x86/kernel/vmlinux.lds.S | 33 -----
arch/x86/tools/relocs.c | 145 +---------------------
arch/x86/xen/xen-head.S | 10 +-
include/asm-generic/vmlinux.lds.h | 1 -
include/linux/percpu-defs.h | 12 --
init/Kconfig | 11 +-
kernel/kallsyms.c | 12 +-
scripts/gcc-x86_32-has-stack-protector.sh | 8 --
scripts/gcc-x86_64-has-stack-protector.sh | 4 -
scripts/kallsyms.c | 68 ++--------
scripts/link-vmlinux.sh | 4 -
23 files changed, 56 insertions(+), 414 deletions(-)
delete mode 100755 scripts/gcc-x86_32-has-stack-protector.sh
delete mode 100755 scripts/gcc-x86_64-has-stack-protector.sh
--
2.31.1
next reply other threads:[~2021-11-30 20:58 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 20:55 Brian Gerst [this message]
2021-11-30 20:55 ` [PATCH v2 1/6] x86: Remove stack protector test scripts Brian Gerst
2021-11-30 20:55 ` [PATCH v2 2/6] x86-64: Convert stack protector to normal percpu variable Brian Gerst
2021-12-01 9:50 ` David Laight
2021-12-01 14:21 ` Brian Gerst
2021-12-02 22:51 ` Peter Zijlstra
2021-11-30 20:55 ` [PATCH v2 3/6] x86-64: Use relative per-cpu offsets Brian Gerst
2021-11-30 20:55 ` [PATCH v2 4/6] x86-64: Remove inverse relocations Brian Gerst
2021-11-30 20:55 ` [PATCH v2 5/6] kallsyms: Remove KALLSYMS_ABSOLUTE_PERCPU Brian Gerst
2021-11-30 20:55 ` [PATCH v2 6/6] percpu: Remove PER_CPU_FIRST_SECTION Brian Gerst
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