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Message-ID: <87a5b0800804230736k340e7fe9mffbd72b5b8164015@mail.gmail.com>
Date: Wed, 23 Apr 2008 15:36:23 +0100
From: "Will Newton" <will.newton@...il.com>
To: "Kyle McMartin" <kyle@...artin.ca>
Cc: "Randy Dunlap" <randy.dunlap@...cle.com>,
"Linux Kernel list" <linux-kernel@...r.kernel.org>,
linux-arch@...r.kernel.org
Subject: Re: [RFC] Introduce __ARCH_WANT_SYS_SYSFS
On Tue, Apr 22, 2008 at 4:38 PM, Kyle McMartin <kyle@...artin.ca> wrote:
> On Tue, Apr 22, 2008 at 04:34:03PM +0100, Will Newton wrote:
> > On Tue, Apr 22, 2008 at 4:24 PM, Kyle McMartin <kyle@...artin.ca> wrote:
> > > On Tue, Apr 22, 2008 at 04:16:17PM +0100, Will Newton wrote:
> > > > It can be done with Kconfig. Whether it should be or not depends on
> > > > your point of view, hence RFC. Currently __ARCH_WANT macros is the way
> > > > syscalls are enabled and disabled across architectures. If there's
> > > > consensus that it should be done via Kconfig that could certainly be
> > > > implmented, but that's a different patch.
> > > >
> > >
> > > It's currently done in unistd.h for hysterical raisins. All new
> > > conditional syscalls have been done in Kconfig.
> >
> > Do you have a syscall in mind that does this in the correct way?
> >
>
> epoll is the most immediate example at hand, since it touches
> fs/compat.c similarly to how you would be touching fs/filesystem.c, and
> touches kernel/sys_ni.c and init/Kconfig in much the same way.
I implemented the approach you suggested - Kconfig symbol and
cond_syscall definition. I think I actually like the previous approach
better:
1. The arch Kconfig files are quite non-uniform compared to unistd.h
so the definitions wind up at different places in the file which is a
bit messy.
2. Changes to Kconfig may cause churn in defconfigs perhaps?
3. There is more churn in arch Kconfig than unistd.h so getting a
cross arch patch applied is likely to be more difficult.
4. The patch is about 4 times as many lines.
What do you think?
>From 094cbe1ca2fa28ae845ef80da6dad02e90cfbe04 Mon Sep 17 00:00:00 2001
From: Will Newton <will.newton@...tec.com>
Date: Wed, 23 Apr 2008 15:28:37 +0100
Subject: [PATCH] Introduce ARCH_HAS_SYS_SYSFS Kconfig symbol.
This symbol should be defined by all arches that implement the sysfs(2)
system call. Arches that do not wish to implement this legacy system call
can save a little bit of kernel code size. The only current architecture
to benefit from this is blackfin, but in the future other arches may wish
to do this as well.
---
arch/alpha/Kconfig | 4 ++++
arch/arm/Kconfig | 4 ++++
arch/avr32/Kconfig | 4 ++++
arch/cris/Kconfig | 4 ++++
arch/frv/Kconfig | 4 ++++
arch/h8300/Kconfig | 4 ++++
arch/ia64/Kconfig | 4 ++++
arch/m32r/Kconfig | 4 ++++
arch/m68k/Kconfig | 4 ++++
arch/m68knommu/Kconfig | 4 ++++
arch/mips/Kconfig | 4 ++++
arch/mn10300/Kconfig | 4 ++++
arch/parisc/Kconfig | 4 ++++
arch/powerpc/Kconfig | 4 ++++
arch/ppc/Kconfig | 4 ++++
arch/s390/Kconfig | 4 ++++
arch/sh/Kconfig | 4 ++++
arch/sparc/Kconfig | 4 ++++
arch/sparc64/Kconfig | 4 ++++
arch/um/Kconfig | 4 ++++
arch/v850/Kconfig | 4 ++++
arch/x86/Kconfig | 4 ++++
arch/xtensa/Kconfig | 4 ++++
fs/filesystems.c | 4 ++++
kernel/sys_ni.c | 1 +
25 files changed, 97 insertions(+), 0 deletions(-)
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 729cdbd..9b7b4d2 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -71,6 +71,10 @@ config AUTO_IRQ_AFFINITY
config ARCH_SUPPORTS_AOUT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
source "init/Kconfig"
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 4039a13..c806808 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -137,6 +137,10 @@ config ZONE_DMA
bool
default y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config GENERIC_ISA_DMA
bool
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 28e0caf..2f9f01d 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -66,6 +66,10 @@ config GENERIC_BUG
def_bool y
depends on BUG
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
source "init/Kconfig"
menu "System Type and features"
diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig
index 9389d38..7aec04b 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig
@@ -32,6 +32,10 @@ config ARCH_HAS_ILOG2_U64
bool
default n
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index a5aac1b..f08fb9a 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -58,6 +58,10 @@ config ARCH_HAS_ILOG2_U64
bool
default y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config HZ
int
default 1000
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 085dc6e..8184c99 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -69,6 +69,10 @@ config TIME_LOW_RES
config ARCH_SUPPORTS_AOUT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config NO_IOPORT
def_bool y
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 8fa3faf..513d960 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -111,6 +111,10 @@ config AUDIT_ARCH
bool
default y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
choice
prompt "System type"
default IA64_GENERIC
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index de153de..79d6f79 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -39,6 +39,10 @@ config NO_DMA
config ARCH_SUPPORTS_AOUT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config HZ
int
default 100
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 65db226..26859b1 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -56,6 +56,10 @@ config NO_DMA
config ARCH_SUPPORTS_AOUT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config HZ
int
default 100
diff --git a/arch/m68knommu/Kconfig b/arch/m68knommu/Kconfig
index 07eb4c4..d9240a6 100644
--- a/arch/m68knommu/Kconfig
+++ b/arch/m68knommu/Kconfig
@@ -68,6 +68,10 @@ config NO_IOPORT
config ARCH_SUPPORTS_AOUT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
source "init/Kconfig"
menu "Processor type and features"
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 8724ed3..0716726 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -752,6 +752,10 @@ config GENERIC_HARDIRQS_NO__DO_IRQ
bool
default n
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
#
# Select some configuration options automatically based on user selections.
#
diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 6a6409a..3666f5f 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -63,6 +63,10 @@ config GENERIC_HARDIRQS
config HOTPLUG_CPU
def_bool n
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config HZ
int
default 1000
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index bc7a19d..c6f5139 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -91,6 +91,10 @@ config ARCH_MAY_HAVE_PC_FDC
depends on BROKEN
default y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
source "init/Kconfig"
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1189d8d..21803f2 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -194,6 +194,10 @@ config PPC_OF_PLATFORM_PCI
depends on PPC64 # not supported on 32 bits yet
default n
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
source "init/Kconfig"
source "arch/powerpc/sysdev/Kconfig"
diff --git a/arch/ppc/Kconfig b/arch/ppc/Kconfig
index abc877f..0156eb2 100644
--- a/arch/ppc/Kconfig
+++ b/arch/ppc/Kconfig
@@ -72,6 +72,10 @@ config GENERIC_BUG
default y
depends on BUG
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
source "init/Kconfig"
menu "Processor"
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 1831833..c04b232 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -55,6 +55,10 @@ config GENERIC_LOCKBREAK
default y
depends on SMP && PREEMPT
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
mainmenu "Linux Kernel Configuration"
config S390
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 8d2cd1d..66b74dc 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -93,6 +93,10 @@ config ARCH_SUPPORTS_AOUT
config IO_TRAPPED
bool
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
source "init/Kconfig"
menu "System type"
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index c40343c..25c17e3 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -30,6 +30,10 @@ config OF
config ARCH_SUPPORTS_AOUT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config HZ
int
default 100
diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig
index 463d1be..9f5d1ed 100644
--- a/arch/sparc64/Kconfig
+++ b/arch/sparc64/Kconfig
@@ -90,6 +90,10 @@ config GENERIC_HARDIRQS_NO__DO_IRQ
config ARCH_SUPPORTS_AOUT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
choice
prompt "Kernel page size"
default SPARC64_PAGE_SIZE_8KB
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index dba8e05..be0cb93 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -68,6 +68,10 @@ config IRQ_RELEASE_METHOD
bool
default y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config HZ
int
default 100
diff --git a/arch/v850/Kconfig b/arch/v850/Kconfig
index 4379f43..b54d1f4 100644
--- a/arch/v850/Kconfig
+++ b/arch/v850/Kconfig
@@ -56,6 +56,10 @@ config ARCH_HAS_ILOG2_U64
config ARCH_SUPPORTS_AOUT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
# Turn off some random 386 crap that can affect device config
config ISA
bool
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 6c70fed..e0b830b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -155,6 +155,10 @@ config GENERIC_PENDING_IRQ
depends on GENERIC_HARDIRQS && SMP
default y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config X86_SMP
bool
depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 9fc8551..7834ad7 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -50,6 +50,10 @@ config ARCH_HAS_ILOG2_U64
config NO_IOPORT
def_bool y
+config ARCH_HAS_SYS_SYSFS
+ bool
+ default y
+
config HZ
int
default 100
diff --git a/fs/filesystems.c b/fs/filesystems.c
index f37f872..f6e1567 100644
--- a/fs/filesystems.c
+++ b/fs/filesystems.c
@@ -118,6 +118,8 @@ int unregister_filesystem(struct file_system_type * fs)
EXPORT_SYMBOL(unregister_filesystem);
+#ifdef CONFIG_ARCH_HAS_SYS_SYSFS
+
static int fs_index(const char __user * __name)
{
struct file_system_type * tmp;
@@ -197,6 +199,8 @@ asmlinkage long sys_sysfs(int option, unsigned
long arg1, unsigned long arg2)
return retval;
}
+#endif
+
int get_filesystem_list(char * buf)
{
int len = 0;
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 5b9b467..866ff4b 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -121,6 +121,7 @@ cond_syscall(sys_vm86old);
cond_syscall(sys_vm86);
cond_syscall(compat_sys_ipc);
cond_syscall(compat_sys_sysctl);
+cond_syscall(sys_sysfs);
/* arch-specific weak syscall entries */
cond_syscall(sys_pciconfig_read);
--
1.5.3.5
View attachment "0001-Introduce-ARCH_HAS_SYS_SYSFS-Kconfig-symbol.patch" of type "text/x-patch" (9402 bytes)
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