[PATCH] mmap2.2: Fix prototype parameter types

There are many slightly different prototypes for this syscall,
but none of them is like the documented one.
Of all the different prototypes,
let's document the asm-generic one.

......

.../linux$ grep_syscall mmap2
arch/csky/kernel/syscall.c:17:
SYSCALL_DEFINE6(mmap2,
	unsigned long, addr,
	unsigned long, len,
	unsigned long, prot,
	unsigned long, flags,
	unsigned long, fd,
	off_t, offset)
arch/microblaze/kernel/sys_microblaze.c:46:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
		unsigned long, prot, unsigned long, flags, unsigned long, fd,
		unsigned long, pgoff)
arch/nds32/kernel/sys_nds32.c:12:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
	       unsigned long, prot, unsigned long, flags,
	       unsigned long, fd, unsigned long, pgoff)
arch/powerpc/kernel/syscalls.c:60:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
		unsigned long, prot, unsigned long, flags,
		unsigned long, fd, unsigned long, pgoff)
arch/riscv/kernel/sys_riscv.c:37:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags,
	unsigned long, fd, off_t, offset)
arch/s390/kernel/sys_s390.c:49:
SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
arch/sparc/kernel/sys_sparc_32.c:101:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long, fd,
	unsigned long, pgoff)
arch/ia64/include/asm/unistd.h:30:
asmlinkage unsigned long sys_mmap2(
				unsigned long addr, unsigned long len,
				int prot, int flags,
				int fd, long pgoff);
arch/ia64/kernel/sys_ia64.c:139:
asmlinkage unsigned long
sys_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, long pgoff)
arch/m68k/kernel/sys_m68k.c:40:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
	unsigned long prot, unsigned long flags,
	unsigned long fd, unsigned long pgoff)
arch/parisc/kernel/sys_parisc.c:275:
asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
	unsigned long prot, unsigned long flags, unsigned long fd,
	unsigned long pgoff)
arch/powerpc/include/asm/syscalls.h:15:
asmlinkage long sys_mmap2(unsigned long addr, size_t len,
		unsigned long prot, unsigned long flags,
		unsigned long fd, unsigned long pgoff);
arch/sh/include/asm/syscalls.h:8:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
			  unsigned long prot, unsigned long flags,
			  unsigned long fd, unsigned long pgoff);
arch/sh/kernel/sys_sh.c:41:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
	unsigned long prot, unsigned long flags,
	unsigned long fd, unsigned long pgoff)
arch/sparc/kernel/systbls.h:23:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
			  unsigned long prot, unsigned long flags,
			  unsigned long fd, unsigned long pgoff);
include/asm-generic/syscalls.h:14:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
			unsigned long prot, unsigned long flags,
			unsigned long fd, unsigned long pgoff);
.../linux$

function grep_syscall()
{
	if ! [ -v 1 ]; then
		>&2 echo "Usage: ${FUNCNAME[0]} <syscall>";
		return ${EX_USAGE};
	fi

	find * -type f \
	|grep '\.c$' \
	|sort -V \
	|xargs pcregrep -Mn "(?s)^\w*SYSCALL_DEFINE.\(${1},.*?\)" \
	|sed -E 's/^[^:]+:[0-9]+:/&\n/';

	find * -type f \
	|grep '\.[ch]$' \
	|sort -V \
	|xargs pcregrep -Mn "(?s)^asmlinkage\s+[\w\s]+\**sys_${1}\s*\(.*?\)" \
	|sed -E 's/^[^:]+:[0-9]+:/&\n/';
}

Signed-off-by: Alejandro Colomar <redacted>
---
 man2/mmap2.2 | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/man2/mmap2.2 b/man2/mmap2.2
index 349ee45e5..f9f9e91cb 100644
--- a/man2/mmap2.2
+++ b/man2/mmap2.2

@@ -33,8 +33,9 @@ mmap2 \- map files or devices into memory
 .nf
 .B #include <sys/mman.h>
 .PP
-.BI "void *mmap2(void *" addr ", size_t " length ", int " prot ,
-.BI "             int " flags ", int " fd ", off_t " pgoffset );
+.BI "void *mmap2(unsigned long " addr ", unsigned long " length ,
+.BI "            unsigned long " prot ", unsigned long " flags ,
+.BI "            unsigned long " fd ", unsigned long " pgoffset );
 .fi
 .SH DESCRIPTION
 This is probably not the system call that you are interested in; instead, see

-- 
2.30.0

There are many slightly different prototypes for this syscall,
but none of them is like the documented one.
Of all the different prototypes,
let's document the asm-generic one.

This manual page was actually using a prototype similar to
mmap(2), but there's no glibc wrapper function called mmap2(2),
as the wrapper for this syscall is mmap(2).  Therefore, the
documented prototype should be the kernel one.

......

.../linux$ grep_syscall mmap2
arch/csky/kernel/syscall.c:17:
SYSCALL_DEFINE6(mmap2,
	unsigned long, addr,
	unsigned long, len,
	unsigned long, prot,
	unsigned long, flags,
	unsigned long, fd,
	off_t, offset)
arch/microblaze/kernel/sys_microblaze.c:46:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
		unsigned long, prot, unsigned long, flags, unsigned long, fd,
		unsigned long, pgoff)
arch/nds32/kernel/sys_nds32.c:12:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
	       unsigned long, prot, unsigned long, flags,
	       unsigned long, fd, unsigned long, pgoff)
arch/powerpc/kernel/syscalls.c:60:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
		unsigned long, prot, unsigned long, flags,
		unsigned long, fd, unsigned long, pgoff)
arch/riscv/kernel/sys_riscv.c:37:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags,
	unsigned long, fd, off_t, offset)
arch/s390/kernel/sys_s390.c:49:
SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
arch/sparc/kernel/sys_sparc_32.c:101:
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
	unsigned long, prot, unsigned long, flags, unsigned long, fd,
	unsigned long, pgoff)
arch/ia64/include/asm/unistd.h:30:
asmlinkage unsigned long sys_mmap2(
				unsigned long addr, unsigned long len,
				int prot, int flags,
				int fd, long pgoff);
arch/ia64/kernel/sys_ia64.c:139:
asmlinkage unsigned long
sys_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, long pgoff)
arch/m68k/kernel/sys_m68k.c:40:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
	unsigned long prot, unsigned long flags,
	unsigned long fd, unsigned long pgoff)
arch/parisc/kernel/sys_parisc.c:275:
asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
	unsigned long prot, unsigned long flags, unsigned long fd,
	unsigned long pgoff)
arch/powerpc/include/asm/syscalls.h:15:
asmlinkage long sys_mmap2(unsigned long addr, size_t len,
		unsigned long prot, unsigned long flags,
		unsigned long fd, unsigned long pgoff);
arch/sh/include/asm/syscalls.h:8:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
			  unsigned long prot, unsigned long flags,
			  unsigned long fd, unsigned long pgoff);
arch/sh/kernel/sys_sh.c:41:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
	unsigned long prot, unsigned long flags,
	unsigned long fd, unsigned long pgoff)
arch/sparc/kernel/systbls.h:23:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
			  unsigned long prot, unsigned long flags,
			  unsigned long fd, unsigned long pgoff);
include/asm-generic/syscalls.h:14:
asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
			unsigned long prot, unsigned long flags,
			unsigned long fd, unsigned long pgoff);
.../linux$

function grep_syscall()
{
	if ! [ -v 1 ]; then
		>&2 echo "Usage: ${FUNCNAME[0]} <syscall>";
		return ${EX_USAGE};
	fi

	find * -type f \
	|grep '\.c$' \
	|sort -V \
	|xargs pcregrep -Mn "(?s)^\w*SYSCALL_DEFINE.\(${1},.*?\)" \
	|sed -E 's/^[^:]+:[0-9]+:/&\n/';

	find * -type f \
	|grep '\.[ch]$' \
	|sort -V \
	|xargs pcregrep -Mn "(?s)^asmlinkage\s+[\w\s]+\**sys_${1}\s*\(.*?\)" \
	|sed -E 's/^[^:]+:[0-9]+:/&\n/';
}

Signed-off-by: Alejandro Colomar <redacted>
---
 man2/mmap2.2 | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/man2/mmap2.2 b/man2/mmap2.2
index 349ee45e5..f9f9e91cb 100644
--- a/man2/mmap2.2
+++ b/man2/mmap2.2

@@ -33,8 +33,9 @@ mmap2 \- map files or devices into memory
 .nf
 .B #include <sys/mman.h>
 .PP
-.BI "void *mmap2(void *" addr ", size_t " length ", int " prot ,
-.BI "             int " flags ", int " fd ", off_t " pgoffset );
+.BI "void *mmap2(unsigned long " addr ", unsigned long " length ,
+.BI "            unsigned long " prot ", unsigned long " flags ,
+.BI "            unsigned long " fd ", unsigned long " pgoffset );
 .fi
 .SH DESCRIPTION
 This is probably not the system call that you are interested in; instead, see

-- 
2.30.0

Hi Alex,

On 2/7/21 1:57 PM, Alejandro Colomar wrote:

There are many slightly different prototypes for this syscall,
but none of them is like the documented one.
Of all the different prototypes,
let's document the asm-generic one.

This manual page was actually using a prototype similar to
mmap(2), 

(Mea culpa...)

but there's no glibc wrapper function called mmap2(2),
as the wrapper for this syscall is mmap(2).  Therefore, the
documented prototype should be the kernel one.

Thanks! Patch applied.

Cheers,

Michael

-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/