[PATCHv4,13/19] kernel: add ksys_personality()

Message ID	20180702110415.10465-14-mark.rutland@arm.com
State	Superseded
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, will.deacon@arm.com Cc: linux-kernel@vger.kernel.org, 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: [PATCHv4 13/19] kernel: add ksys_personality() Date: Mon, 2 Jul 2018 12:04:09 +0100 Message-Id: <20180702110415.10465-14-mark.rutland@arm.com> In-Reply-To: <20180702110415.10465-1-mark.rutland@arm.com> References: <20180702110415.10465-1-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk
Series	arm64: invoke syscalls with pt_regs \| expand [PATCHv4,00/19] arm64: invoke syscalls with pt_regs [PATCHv4,01/19] arm64: consistently use unsigned long for thread flags [PATCHv4,02/19] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> [PATCHv4,03/19] arm64: kill config_sctlr_el1() [PATCHv4,04/19] arm64: kill change_cpacr() [PATCHv4,05/19] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> [PATCHv4,06/19] arm64: remove sigreturn wrappers [PATCHv4,07/19] arm64: convert raw syscall invocation to C [PATCHv4,08/19] arm64: convert syscall trace logic to C [PATCHv4,09/19] arm64: convert native/compat syscall entry to C [PATCHv4,10/19] arm64: don't restore GPRs when context tracking [PATCHv4,11/19] arm64: don't reload GPRs after apply_ssbd [PATCHv4,12/19] arm64: zero GPRs upon entry from EL0 [PATCHv4,13/19] kernel: add ksys_personality() [PATCHv4,14/19] kernel: add kcompat_sys_{f,}statfs64() [PATCHv4,15/19] arm64: remove in-kernel call to sys_personality() [PATCHv4,16/19] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn [PATCHv4,17/19] arm64: use SYSCALL_DEFINE6() for mmap [PATCHv4,18/19] arm64: convert compat wrappers to C [PATCHv4,19/19] arm64: implement syscall wrappers

Message ID

20180702110415.10465-14-mark.rutland@arm.com

State

Superseded

Headers

Received-SPF: pass (google.com: best guess record for domain of
	linux-kernel-owner@vger.kernel.org designates 209.132.180.67
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From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org, will.deacon@arm.com
Cc: linux-kernel@vger.kernel.org, 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: [PATCHv4 13/19] kernel: add ksys_personality()
Date: Mon,  2 Jul 2018 12:04:09 +0100
Message-Id: <20180702110415.10465-14-mark.rutland@arm.com>
In-Reply-To: <20180702110415.10465-1-mark.rutland@arm.com>
References: <20180702110415.10465-1-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 2, 2018, 11:04 a.m. UTC

Using this helper allows us to avoid the in-kernel call to the
sys_personality() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it
uses the same calling convention as sys_personality().

Since ksys_personality is trivial, it is implemented directly in
<linux/syscalls.h>, as we do for ksys_close() and friends.

This helper is necessary to enable conversion of arm64's syscall
handling to use pt_regs wrappers.

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

Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Martin <dave.martin@arm.com>
---
 include/linux/syscalls.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

-- 
2.11.0

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index a368a68cb667..abfe12d8a9c5 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -80,6 +80,7 @@  union bpf_attr;
 #include <linux/unistd.h>
 #include <linux/quota.h>
 #include <linux/key.h>
+#include <linux/personality.h>
 #include <trace/syscall.h>
 
 #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
@@ -1281,4 +1282,14 @@  static inline long ksys_truncate(const char __user *pathname, loff_t length)
 	return do_sys_truncate(pathname, length);
 }
 
+static inline unsigned int ksys_personality(unsigned int personality)
+{
+	unsigned int old = current->personality;
+
+	if (personality != 0xffffffff)
+		set_personality(personality);
+
+	return old;
+}
+
 #endif

[PATCHv4,13/19] kernel: add ksys_personality()

Commit Message

Patch