[PATCHv5,14/21] arm64: drop alignment from syscall tables

Message ID	20180711135656.20670-15-mark.rutland@arm.com
State	Accepted
Commit	80d63bc39f9ace9c1d2bef7f921d2f3ef2037d4b
Headers	show Delivered-To: patch@linaro.org Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; From: Mark Rutland <mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, will.deacon@arm.com Cc: catalin.marinas@arm.com, dave.martin@arm.com, hch@infradead.org, james.morse@arm.com, linux@dominikbrodowski.net, linux-fsdevel@vger.kernel.org, marc.zyngier@arm.com, mark.rutland@arm.com, viro@zeniv.linux.org.uk Subject: [PATCHv5 14/21] arm64: drop alignment from syscall tables Date: Wed, 11 Jul 2018 14:56:49 +0100 Message-Id: <20180711135656.20670-15-mark.rutland@arm.com> In-Reply-To: <20180711135656.20670-1-mark.rutland@arm.com> References: <20180711135656.20670-1-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk
Series	arm64: invoke syscalls with pt_regs \| expand [PATCHv5,00/21] arm64: invoke syscalls with pt_regs [PATCHv5,01/21] arm64: consistently use unsigned long for thread flags [PATCHv5,02/21] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> [PATCHv5,03/21] arm64: kill config_sctlr_el1() [PATCHv5,04/21] arm64: kill change_cpacr() [PATCHv5,05/21] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> [PATCHv5,06/21] arm64: remove sigreturn wrappers [PATCHv5,07/21] arm64: introduce syscall_fn_t [PATCHv5,08/21] arm64: convert raw syscall invocation to C [PATCHv5,09/21] arm64: convert syscall trace logic to C [PATCHv5,10/21] arm64: convert native/compat syscall entry to C [PATCHv5,11/21] arm64: don't restore GPRs when context tracking [PATCHv5,12/21] arm64: don't reload GPRs after apply_ssbd [PATCHv5,13/21] arm64: zero GPRs upon entry from EL0 [PATCHv5,14/21] arm64: drop alignment from syscall tables [PATCHv5,15/21] kernel: add ksys_personality() [PATCHv5,16/21] kernel: add kcompat_sys_{f,}statfs64() [PATCHv5,17/21] arm64: remove in-kernel call to sys_personality() [PATCHv5,18/21] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn [PATCHv5,19/21] arm64: use SYSCALL_DEFINE6() for mmap [PATCHv5,20/21] arm64: convert compat wrappers to C [PATCHv5,21/21] arm64: implement syscall wrappers

Message ID

20180711135656.20670-15-mark.rutland@arm.com

State

Accepted

Commit

80d63bc39f9ace9c1d2bef7f921d2f3ef2037d4b

Headers

Received-SPF: pass (google.com: best guess record for domain of
	linux-kernel-owner@vger.kernel.org designates 209.132.180.67
	as permitted sender) client-ip=209.132.180.67; 
From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
	will.deacon@arm.com
Cc: catalin.marinas@arm.com, dave.martin@arm.com, hch@infradead.org,
	james.morse@arm.com, linux@dominikbrodowski.net,
	linux-fsdevel@vger.kernel.org, marc.zyngier@arm.com,
	mark.rutland@arm.com, viro@zeniv.linux.org.uk
Subject: [PATCHv5 14/21] arm64: drop alignment from syscall tables
Date: Wed, 11 Jul 2018 14:56:49 +0100
Message-Id: <20180711135656.20670-15-mark.rutland@arm.com>
In-Reply-To: <20180711135656.20670-1-mark.rutland@arm.com>
References: <20180711135656.20670-1-mark.rutland@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Series

arm64: invoke syscalls with pt_regs | expand

Commit Message

Mark Rutland July 11, 2018, 1:56 p.m. UTC

Our syscall tables are aligned to 4096 bytes, which allowed their
addresses to be generated with a single adrp in entry.S. This has the
unfortunate property of wasting space in .rodata for the necessary
padding.

Now that the address is generated by C code, we can rely on the compiler
to do the right thing, and drop the alignemnt.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/kernel/sys.c   | 6 +-----
 arch/arm64/kernel/sys32.c | 6 +-----
 2 files changed, 2 insertions(+), 10 deletions(-)

-- 
2.11.0

diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c
index 7f0907261269..df8180175515 100644
--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -56,11 +56,7 @@  asmlinkage long sys_rt_sigreturn(void);
 #undef __SYSCALL
 #define __SYSCALL(nr, sym)	[nr] = (syscall_fn_t)sym,
 
-/*
- * The sys_call_table array must be 4K aligned to be accessible from
- * kernel/entry.S.
- */
-const syscall_fn_t sys_call_table[__NR_syscalls] __aligned(4096) = {
+const syscall_fn_t sys_call_table[__NR_syscalls] = {
 	[0 ... __NR_syscalls - 1] = (syscall_fn_t)sys_ni_syscall,
 #include <asm/unistd.h>
 };
diff --git a/arch/arm64/kernel/sys32.c b/arch/arm64/kernel/sys32.c
index d993214118aa..4ddeaae90128 100644
--- a/arch/arm64/kernel/sys32.c
+++ b/arch/arm64/kernel/sys32.c
@@ -44,11 +44,7 @@  asmlinkage long compat_sys_mmap2_wrapper(void);
 #undef __SYSCALL
 #define __SYSCALL(nr, sym)	[nr] = (syscall_fn_t)sym,
 
-/*
- * The sys_call_table array must be 4K aligned to be accessible from
- * kernel/entry.S.
- */
-const syscall_fn_t compat_sys_call_table[__NR_compat_syscalls] __aligned(4096) = {
+const syscall_fn_t compat_sys_call_table[__NR_compat_syscalls] = {
 	[0 ... __NR_compat_syscalls - 1] = (syscall_fn_t)sys_ni_syscall,
 #include <asm/unistd32.h>
 };

[PATCHv5,14/21] arm64: drop alignment from syscall tables

Commit Message

Patch