[PATCHv2,14/19] kernel: add kcompat_sys_{f,}statfs64()

Message ID	20180601112441.37810-15-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State	Superseded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, linux-kernel@vger.kernel.org, will.deacon@arm.com, catalin.marinas@arm.com Cc: Mark Rutland <mark.rutland@arm.com>, Al Viro <viro@zeniv.linux.org.uk>, linux-fsdevel@vger.kernel.org Subject: [PATCHv2 14/19] kernel: add kcompat_sys_{f,}statfs64() Date: Fri, 1 Jun 2018 12:24:36 +0100 Message-Id: <20180601112441.37810-15-mark.rutland@arm.com> In-Reply-To: <20180601112441.37810-1-mark.rutland@arm.com> References: <20180601112441.37810-1-mark.rutland@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk
Series	arm64: invoke syscalls with pt_regs \| expand [PATCHv2,00/19] arm64: invoke syscalls with pt_regs [PATCHv2,01/19] arm64: consistently use unsigned long for thread flags [PATCHv2,02/19] arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h> [PATCHv2,03/19] arm64: introduce sysreg_clear_set() [PATCHv2,04/19] arm64: kill config_sctlr_el1() [PATCHv2,05/19] arm64: kill change_cpacr() [PATCHv2,06/19] arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> [PATCHv2,07/19] arm64: remove sigreturn wrappers [PATCHv2,08/19] arm64: convert raw syscall invocation to C [PATCHv2,09/19] arm64: convert syscall trace logic to C [PATCHv2,10/19] arm64: convert native/compat syscall entry to C [PATCHv2,11/19] arm64: don't reload GPRs after apply_ssbd [PATCHv2,12/19] arm64: zero GPRs upon entry from EL0 [PATCHv2,13/19] kernel: add ksys_personality() [PATCHv2,14/19] kernel: add kcompat_sys_{f,}statfs64() [PATCHv2,15/19] arm64: remove in-kernel call to sys_personality() [PATCHv2,16/19] arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn [PATCHv2,17/19] arm64: use SYSCALL_DEFINE6() for mmap [PATCHv2,18/19] arm64: convert compat wrappers to C [PATCHv2,19/19] arm64: implement syscall wrappers

Message ID

20180601112441.37810-15-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Superseded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
	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, catalin.marinas@arm.com
Cc: Mark Rutland <mark.rutland@arm.com>, Al Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel@vger.kernel.org
Subject: [PATCHv2 14/19] kernel: add kcompat_sys_{f,}statfs64()
Date: Fri,  1 Jun 2018 12:24:36 +0100
Message-Id: <20180601112441.37810-15-mark.rutland@arm.com>
In-Reply-To: <20180601112441.37810-1-mark.rutland@arm.com>
References: <20180601112441.37810-1-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 June 1, 2018, 11:24 a.m. UTC

Using this helper allows us to avoid the in-kernel calls to the
compat_sys_{f,}statfs64() sycalls, as are necessary for parameter
mangling in arm64's compat handling.

Following the example of ksys_* functions, kcompat_sys_* functions are
intended to be a drop-in replacement for their compat_sys_*
counterparts, with the same calling convention.

This 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: linux-fsdevel@vger.kernel.org
---
 fs/statfs.c            | 14 ++++++++++++--
 include/linux/compat.h | 11 +++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

-- 
2.11.0

diff --git a/fs/statfs.c b/fs/statfs.c
index 5b2a24f0f263..f0216629621d 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -335,7 +335,7 @@  static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstat
 	return 0;
 }
 
-COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf)
+int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz, struct compat_statfs64 __user * buf)
 {
 	struct kstatfs tmp;
 	int error;
@@ -349,7 +349,12 @@  COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, s
 	return error;
 }
 
-COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf)
+COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf)
+{
+	return kcompat_sys_statfs64(pathname, sz, buf);
+}
+
+int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user * buf)
 {
 	struct kstatfs tmp;
 	int error;
@@ -363,6 +368,11 @@  COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct co
 	return error;
 }
 
+COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf)
+{
+	return kcompat_sys_fstatfs64(fd, sz, buf);
+}
+
 /*
  * This is a copy of sys_ustat, just dealing with a structure layout.
  * Given how simple this syscall is that apporach is more maintainable
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 081281ad5772..6cecf9f11d6b 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -1013,6 +1013,17 @@  static inline struct compat_timeval ns_to_compat_timeval(s64 nsec)
 	return ctv;
 }
 
+/*
+ * Kernel code should not call compat syscalls (i.e., compat_sys_xyzyyz())
+ * directly.  Instead, use one of the functions which work equivalently, such
+ * as the kcompat_sys_xyzyyz() functions prototyped below.
+ */
+
+int kcompat_sys_statfs64(const char __user * pathname, compat_size_t sz,
+		     struct compat_statfs64 __user * buf);
+int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz,
+			  struct compat_statfs64 __user * buf);
+
 #else /* !CONFIG_COMPAT */
 
 #define is_compat_task() (0)

[PATCHv2,14/19] kernel: add kcompat_sys_{f,}statfs64()

Commit Message

Patch