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From:   Alejandro Colomar <alx.manpages@gmail.com>
To:     mtk.manpages@gmail.com
Cc:     Alejandro Colomar <alx.manpages@gmail.com>,
        linux-man@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] spu_create.2: Clarify that one of the prototypes is the current one
Date:   Thu, 26 Nov 2020 19:32:12 +0100
Message-Id: <20201126183211.21857-1-alx.manpages@gmail.com>
MIME-Version: 1.0
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The current Linux kernel only provides a definition of 'spu_create()'.
It has 4 parameters, the last being 'int neighbor_fd'.

Before Linux 2.6.23, there was an older prototype,
which didn't have this last parameter.

Move that old prototype to VERSIONS,
and keep the current one in SYNOPSIS.

......

$ grep -rn "SYSCALL_DEFINE.(spu_create"
arch/powerpc/platforms/cell/spu_syscalls.c:56:
SYSCALL_DEFINE4(spu_create, const char __user *, name, unsigned int, flags,

$ sed -n 56,/^}/p arch/powerpc/platforms/cell/spu_syscalls.c
SYSCALL_DEFINE4(spu_create, const char __user *, name, unsigned int, flags,
	umode_t, mode, int, neighbor_fd)
{
	long ret;
	struct spufs_calls *calls;

	calls = spufs_calls_get();
	if (!calls)
		return -ENOSYS;

	if (flags & SPU_CREATE_AFFINITY_SPU) {
		struct fd neighbor = fdget(neighbor_fd);
		ret = -EBADF;
		if (neighbor.file) {
			ret = calls->create_thread(name, flags, mode, neighbor.file);
			fdput(neighbor);
		}
	} else
		ret = calls->create_thread(name, flags, mode, NULL);

	spufs_calls_put(calls);
	return ret;
}

$ git blame arch/powerpc/platforms/cell/spu_syscalls.c -L 56,/\)/
1bc94226d5c64 (Al Viro 2011-07-26 16:50:23 -0400 56)
SYSCALL_DEFINE4(spu_create, const char __user *, name, unsigned int, flags,
1bc94226d5c64 (Al Viro 2011-07-26 16:50:23 -0400 57)
   umode_t, mode, int, neighbor_fd)

$ git checkout 1bc94226d5c64~1
$ git blame arch/powerpc/platforms/cell/spu_syscalls.c -L /spu_create/,/\)/
67207b9664a8d (Arnd Bergmann 2005-11-15 15:53:48 -0500 68)
asmlinkage long sys_spu_create(const char __user *name,
8e68e2f248332 (Arnd Bergmann 2007-07-20 21:39:47 +0200 69)
             unsigned int flags, mode_t mode, int neighbor_fd)

$ git checkout 8e68e2f248332~1
$ git blame arch/powerpc/platforms/cell/spu_syscalls.c -L /spu_create/,/\)/
67207b9664a8d (Arnd Bergmann 2005-11-15 15:53:48 -0500 36)
asmlinkage long sys_spu_create(const char __user *name,
67207b9664a8d (Arnd Bergmann 2005-11-15 15:53:48 -0500 37)
             unsigned int flags, mode_t mode)

$ git describe --contains 8e68e2f248332
v2.6.23-rc1~195^2~7

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
---
 man2/spu_create.2 | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/man2/spu_create.2 b/man2/spu_create.2
index 4e6f5d730..3eeafee56 100644
--- a/man2/spu_create.2
+++ b/man2/spu_create.2
@@ -30,9 +30,8 @@ spu_create \- create a new spu context
 .B #include <sys/types.h>
 .B #include <sys/spu.h>
 .PP
-.BI "int spu_create(const char *" pathname ", int " flags ", mode_t " mode ");"
-.BI "int spu_create(const char *" pathname ", int " flags ", mode_t " mode ","
-.BI "               int " neighbor_fd ");"
+.BI "int spu_create(const char *" pathname ", int " flags ", mode_t " mode ,
+.BI "               int " neighbor_fd );
 .fi
 .PP
 .IR Note :
@@ -247,6 +246,17 @@ By convention, it gets mounted in
 The
 .BR spu_create ()
 system call was added to Linux in kernel 2.6.16.
+.PP
+.\" commit 8e68e2f248332a9c3fd4f08258f488c209bd3e0c
+Before Linux 2.6.23, the prototype for
+.BR spu_create ()
+was:
+.PP
+.in +4n
+.EX
+.BI "int spu_create(const char *" pathname ", int " flags ", mode_t " mode );
+.EE
+.in
 .SH CONFORMING TO
 This call is Linux-specific and implemented only on the PowerPC
 architecture.
-- 
2.29.2