Patchwork [1/3] lib: fwts_ioport: add helper functions to do port I/O

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Submitter Colin King
Date Jan. 15, 2013, 12:25 p.m.
Message ID <1358252735-14227-2-git-send-email-colin.king@canonical.com>
Download mbox | patch
Permalink /patch/212144/
State Accepted
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Comments

Colin King - Jan. 15, 2013, 12:25 p.m.
From: Colin Ian King <colin.king@canonical.com>

When testing on a Xen Dom0 I discovered that restricted port I/O causes
a segfault.  This patch adds a thin layer of abstraction onto the
port read/write operations to catch segfaults and to return FWTS_ERROR.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 src/lib/include/fwts.h        |   1 +
 src/lib/include/fwts_ioport.h |  32 ++++++++++
 src/lib/src/Makefile.am       |   1 +
 src/lib/src/fwts_ioport.c     | 136 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 170 insertions(+)
 create mode 100644 src/lib/include/fwts_ioport.h
 create mode 100644 src/lib/src/fwts_ioport.c
Keng-Yu Lin - Jan. 29, 2013, 8:30 a.m.
On Tue, Jan 15, 2013 at 8:25 PM, Colin King <colin.king@canonical.com> wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> When testing on a Xen Dom0 I discovered that restricted port I/O causes
> a segfault.  This patch adds a thin layer of abstraction onto the
> port read/write operations to catch segfaults and to return FWTS_ERROR.
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  src/lib/include/fwts.h        |   1 +
>  src/lib/include/fwts_ioport.h |  32 ++++++++++
>  src/lib/src/Makefile.am       |   1 +
>  src/lib/src/fwts_ioport.c     | 136 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 170 insertions(+)
>  create mode 100644 src/lib/include/fwts_ioport.h
>  create mode 100644 src/lib/src/fwts_ioport.c
>
> diff --git a/src/lib/include/fwts.h b/src/lib/include/fwts.h
> index 414252d..cbf9dd9 100644
> --- a/src/lib/include/fwts.h
> +++ b/src/lib/include/fwts.h
> @@ -78,5 +78,6 @@
>  #include "fwts_battery.h"
>  #include "fwts_button.h"
>  #include "fwts_json.h"
> +#include "fwts_ioport.h"
>
>  #endif
> diff --git a/src/lib/include/fwts_ioport.h b/src/lib/include/fwts_ioport.h
> new file mode 100644
> index 0000000..183fb4a
> --- /dev/null
> +++ b/src/lib/include/fwts_ioport.h
> @@ -0,0 +1,32 @@
> +/*
> + * Copyright (C) 2013 Canonical
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + *
> + */
> +#ifndef __FWTS_IO_PORT_H__
> +#define __FWTS_IO_PORT_H__
> +
> +#include <stdint.h>
> +
> +int fwts_inb(uint32_t port, uint8_t *value);
> +int fwts_inw(uint32_t port, uint16_t *value);
> +int fwts_inl(uint32_t port, uint32_t *value);
> +
> +int fwts_outb(uint32_t port, uint8_t value);
> +int fwts_outw(uint32_t port, uint16_t value);
> +int fwts_outl(uint32_t port, uint32_t value);
> +
> +#endif
> diff --git a/src/lib/src/Makefile.am b/src/lib/src/Makefile.am
> index a91d9ab..6a44641 100644
> --- a/src/lib/src/Makefile.am
> +++ b/src/lib/src/Makefile.am
> @@ -44,6 +44,7 @@ libfwts_la_SOURCES =          \
>         fwts_hwinfo.c           \
>         fwts_iasl.c             \
>         fwts_interactive.c      \
> +       fwts_ioport.c           \
>         fwts_keymap.c           \
>         fwts_klog.c             \
>         fwts_list.c             \
> diff --git a/src/lib/src/fwts_ioport.c b/src/lib/src/fwts_ioport.c
> new file mode 100644
> index 0000000..bc6243e
> --- /dev/null
> +++ b/src/lib/src/fwts_ioport.c
> @@ -0,0 +1,136 @@
> +/*
> + * Copyright (C) 2013 Canonical
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + *
> + */
> +
> +#include <sys/io.h>
> +#include <stdint.h>
> +#include <signal.h>
> +#include <setjmp.h>
> +
> +#include "fwts.h"
> +
> +static jmp_buf jmpbuf;
> +
> +/*
> + *  If we hit a SIGSEGV then the port read
> + *  failed and we longjmp back and return
> + *  FWTS_ERROR
> + */
> +static void segv_handler(int dummy)
> +{
> +       FWTS_UNUSED(dummy);
> +
> +       signal(SIGSEGV, SIG_DFL);
> +       longjmp(jmpbuf, 1);
> +}
> +
> +/*
> + *  fwts_inb()
> + *     8 bit port read, handle access errors
> + */
> +int fwts_inb(uint32_t port, uint8_t *value)
> +{
> +       if (setjmp(jmpbuf) != 0)
> +               return FWTS_ERROR;
> +
> +       signal(SIGSEGV, segv_handler);
> +       *value = inb(port);
> +       signal(SIGSEGV, SIG_DFL);
> +
> +       return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_inw()
> + *     16 bit port read, handle access errors
> + */
> +int fwts_inw(uint32_t port, uint16_t *value)
> +{
> +       if (setjmp(jmpbuf) != 0)
> +               return FWTS_ERROR;
> +
> +       signal(SIGSEGV, segv_handler);
> +       *value = inw(port);
> +       signal(SIGSEGV, SIG_DFL);
> +
> +       return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_inl()
> + *     32 bit port read, handle access errors
> + */
> +int fwts_inl(uint32_t port, uint32_t *value)
> +{
> +       if (setjmp(jmpbuf) != 0)
> +               return FWTS_ERROR;
> +
> +       signal(SIGSEGV, segv_handler);
> +       *value = inl(port);
> +       signal(SIGSEGV, SIG_DFL);
> +
> +       return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outb()
> + *     8 bit port write, handle access errors
> + */
> +int fwts_outb(uint32_t port, uint8_t value)
> +{
> +       if (setjmp(jmpbuf) != 0)
> +               return FWTS_ERROR;
> +
> +       signal(SIGSEGV, segv_handler);
> +       outb(port, value);
> +       signal(SIGSEGV, SIG_DFL);
> +
> +       return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outw()
> + *     16 bit port write, handle access errors
> + */
> +int fwts_outw(uint32_t port, uint16_t value)
> +{
> +       if (setjmp(jmpbuf) != 0)
> +               return FWTS_ERROR;
> +
> +       signal(SIGSEGV, segv_handler);
> +       outw(port, value);
> +       signal(SIGSEGV, SIG_DFL);
> +
> +       return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outl()
> + *     32 bit port write, handle access errors
> + */
> +int fwts_outl(uint32_t port, uint32_t value)
> +{
> +       if (setjmp(jmpbuf) != 0)
> +               return FWTS_ERROR;
> +
> +       signal(SIGSEGV, segv_handler);
> +       outw(port, value);
> +       signal(SIGSEGV, SIG_DFL);
> +
> +       return FWTS_OK;
> +}
> --
> 1.8.0
>
Acked-by: Keng-Yu Lin <kengyu@canonical.com>
Ivan Hu - Feb. 1, 2013, 2:03 a.m.
On 01/15/2013 08:25 PM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> When testing on a Xen Dom0 I discovered that restricted port I/O causes
> a segfault.  This patch adds a thin layer of abstraction onto the
> port read/write operations to catch segfaults and to return FWTS_ERROR.
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   src/lib/include/fwts.h        |   1 +
>   src/lib/include/fwts_ioport.h |  32 ++++++++++
>   src/lib/src/Makefile.am       |   1 +
>   src/lib/src/fwts_ioport.c     | 136 ++++++++++++++++++++++++++++++++++++++++++
>   4 files changed, 170 insertions(+)
>   create mode 100644 src/lib/include/fwts_ioport.h
>   create mode 100644 src/lib/src/fwts_ioport.c
>
> diff --git a/src/lib/include/fwts.h b/src/lib/include/fwts.h
> index 414252d..cbf9dd9 100644
> --- a/src/lib/include/fwts.h
> +++ b/src/lib/include/fwts.h
> @@ -78,5 +78,6 @@
>   #include "fwts_battery.h"
>   #include "fwts_button.h"
>   #include "fwts_json.h"
> +#include "fwts_ioport.h"
>
>   #endif
> diff --git a/src/lib/include/fwts_ioport.h b/src/lib/include/fwts_ioport.h
> new file mode 100644
> index 0000000..183fb4a
> --- /dev/null
> +++ b/src/lib/include/fwts_ioport.h
> @@ -0,0 +1,32 @@
> +/*
> + * Copyright (C) 2013 Canonical
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + *
> + */
> +#ifndef __FWTS_IO_PORT_H__
> +#define __FWTS_IO_PORT_H__
> +
> +#include <stdint.h>
> +
> +int fwts_inb(uint32_t port, uint8_t *value);
> +int fwts_inw(uint32_t port, uint16_t *value);
> +int fwts_inl(uint32_t port, uint32_t *value);
> +
> +int fwts_outb(uint32_t port, uint8_t value);
> +int fwts_outw(uint32_t port, uint16_t value);
> +int fwts_outl(uint32_t port, uint32_t value);
> +
> +#endif
> diff --git a/src/lib/src/Makefile.am b/src/lib/src/Makefile.am
> index a91d9ab..6a44641 100644
> --- a/src/lib/src/Makefile.am
> +++ b/src/lib/src/Makefile.am
> @@ -44,6 +44,7 @@ libfwts_la_SOURCES = 		\
>   	fwts_hwinfo.c 		\
>   	fwts_iasl.c 		\
>   	fwts_interactive.c 	\
> +	fwts_ioport.c		\
>   	fwts_keymap.c 		\
>   	fwts_klog.c 		\
>   	fwts_list.c 		\
> diff --git a/src/lib/src/fwts_ioport.c b/src/lib/src/fwts_ioport.c
> new file mode 100644
> index 0000000..bc6243e
> --- /dev/null
> +++ b/src/lib/src/fwts_ioport.c
> @@ -0,0 +1,136 @@
> +/*
> + * Copyright (C) 2013 Canonical
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + *
> + */
> +
> +#include <sys/io.h>
> +#include <stdint.h>
> +#include <signal.h>
> +#include <setjmp.h>
> +
> +#include "fwts.h"
> +
> +static jmp_buf jmpbuf;
> +
> +/*
> + *  If we hit a SIGSEGV then the port read
> + *  failed and we longjmp back and return
> + *  FWTS_ERROR
> + */
> +static void segv_handler(int dummy)
> +{
> +	FWTS_UNUSED(dummy);
> +
> +	signal(SIGSEGV, SIG_DFL);
> +	longjmp(jmpbuf, 1);
> +}
> +
> +/*
> + *  fwts_inb()
> + *	8 bit port read, handle access errors
> + */
> +int fwts_inb(uint32_t port, uint8_t *value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	*value = inb(port);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_inw()
> + *	16 bit port read, handle access errors
> + */
> +int fwts_inw(uint32_t port, uint16_t *value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	*value = inw(port);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_inl()
> + *	32 bit port read, handle access errors
> + */
> +int fwts_inl(uint32_t port, uint32_t *value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	*value = inl(port);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outb()
> + *	8 bit port write, handle access errors
> + */
> +int fwts_outb(uint32_t port, uint8_t value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	outb(port, value);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outw()
> + *	16 bit port write, handle access errors
> + */
> +int fwts_outw(uint32_t port, uint16_t value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	outw(port, value);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outl()
> + *	32 bit port write, handle access errors
> + */
> +int fwts_outl(uint32_t port, uint32_t value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	outw(port, value);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
>
Acked-by: Ivan Hu <ivan.hu@canonical.com>
Alex Hung - Feb. 4, 2013, 12:16 a.m.
On 01/15/2013 04:25 AM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> When testing on a Xen Dom0 I discovered that restricted port I/O causes
> a segfault.  This patch adds a thin layer of abstraction onto the
> port read/write operations to catch segfaults and to return FWTS_ERROR.
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   src/lib/include/fwts.h        |   1 +
>   src/lib/include/fwts_ioport.h |  32 ++++++++++
>   src/lib/src/Makefile.am       |   1 +
>   src/lib/src/fwts_ioport.c     | 136 ++++++++++++++++++++++++++++++++++++++++++
>   4 files changed, 170 insertions(+)
>   create mode 100644 src/lib/include/fwts_ioport.h
>   create mode 100644 src/lib/src/fwts_ioport.c
>
> diff --git a/src/lib/include/fwts.h b/src/lib/include/fwts.h
> index 414252d..cbf9dd9 100644
> --- a/src/lib/include/fwts.h
> +++ b/src/lib/include/fwts.h
> @@ -78,5 +78,6 @@
>   #include "fwts_battery.h"
>   #include "fwts_button.h"
>   #include "fwts_json.h"
> +#include "fwts_ioport.h"
>
>   #endif
> diff --git a/src/lib/include/fwts_ioport.h b/src/lib/include/fwts_ioport.h
> new file mode 100644
> index 0000000..183fb4a
> --- /dev/null
> +++ b/src/lib/include/fwts_ioport.h
> @@ -0,0 +1,32 @@
> +/*
> + * Copyright (C) 2013 Canonical
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + *
> + */
> +#ifndef __FWTS_IO_PORT_H__
> +#define __FWTS_IO_PORT_H__
> +
> +#include <stdint.h>
> +
> +int fwts_inb(uint32_t port, uint8_t *value);
> +int fwts_inw(uint32_t port, uint16_t *value);
> +int fwts_inl(uint32_t port, uint32_t *value);
> +
> +int fwts_outb(uint32_t port, uint8_t value);
> +int fwts_outw(uint32_t port, uint16_t value);
> +int fwts_outl(uint32_t port, uint32_t value);
> +
> +#endif
> diff --git a/src/lib/src/Makefile.am b/src/lib/src/Makefile.am
> index a91d9ab..6a44641 100644
> --- a/src/lib/src/Makefile.am
> +++ b/src/lib/src/Makefile.am
> @@ -44,6 +44,7 @@ libfwts_la_SOURCES = 		\
>   	fwts_hwinfo.c 		\
>   	fwts_iasl.c 		\
>   	fwts_interactive.c 	\
> +	fwts_ioport.c		\
>   	fwts_keymap.c 		\
>   	fwts_klog.c 		\
>   	fwts_list.c 		\
> diff --git a/src/lib/src/fwts_ioport.c b/src/lib/src/fwts_ioport.c
> new file mode 100644
> index 0000000..bc6243e
> --- /dev/null
> +++ b/src/lib/src/fwts_ioport.c
> @@ -0,0 +1,136 @@
> +/*
> + * Copyright (C) 2013 Canonical
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + *
> + */
> +
> +#include <sys/io.h>
> +#include <stdint.h>
> +#include <signal.h>
> +#include <setjmp.h>
> +
> +#include "fwts.h"
> +
> +static jmp_buf jmpbuf;
> +
> +/*
> + *  If we hit a SIGSEGV then the port read
> + *  failed and we longjmp back and return
> + *  FWTS_ERROR
> + */
> +static void segv_handler(int dummy)
> +{
> +	FWTS_UNUSED(dummy);
> +
> +	signal(SIGSEGV, SIG_DFL);
> +	longjmp(jmpbuf, 1);
> +}
> +
> +/*
> + *  fwts_inb()
> + *	8 bit port read, handle access errors
> + */
> +int fwts_inb(uint32_t port, uint8_t *value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	*value = inb(port);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_inw()
> + *	16 bit port read, handle access errors
> + */
> +int fwts_inw(uint32_t port, uint16_t *value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	*value = inw(port);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_inl()
> + *	32 bit port read, handle access errors
> + */
> +int fwts_inl(uint32_t port, uint32_t *value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	*value = inl(port);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outb()
> + *	8 bit port write, handle access errors
> + */
> +int fwts_outb(uint32_t port, uint8_t value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	outb(port, value);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outw()
> + *	16 bit port write, handle access errors
> + */
> +int fwts_outw(uint32_t port, uint16_t value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	outw(port, value);
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  fwts_outl()
> + *	32 bit port write, handle access errors
> + */
> +int fwts_outl(uint32_t port, uint32_t value)
> +{
> +	if (setjmp(jmpbuf) != 0)
> +		return FWTS_ERROR;
> +
> +	signal(SIGSEGV, segv_handler);
> +	outw(port, value);
Does it mean *outl* here?
> +	signal(SIGSEGV, SIG_DFL);
> +
> +	return FWTS_OK;
> +}
>

Everything else look good to me.

Patch

diff --git a/src/lib/include/fwts.h b/src/lib/include/fwts.h
index 414252d..cbf9dd9 100644
--- a/src/lib/include/fwts.h
+++ b/src/lib/include/fwts.h
@@ -78,5 +78,6 @@ 
 #include "fwts_battery.h"
 #include "fwts_button.h"
 #include "fwts_json.h"
+#include "fwts_ioport.h"
 
 #endif
diff --git a/src/lib/include/fwts_ioport.h b/src/lib/include/fwts_ioport.h
new file mode 100644
index 0000000..183fb4a
--- /dev/null
+++ b/src/lib/include/fwts_ioport.h
@@ -0,0 +1,32 @@ 
+/*
+ * Copyright (C) 2013 Canonical
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+#ifndef __FWTS_IO_PORT_H__
+#define __FWTS_IO_PORT_H__
+
+#include <stdint.h>
+
+int fwts_inb(uint32_t port, uint8_t *value);
+int fwts_inw(uint32_t port, uint16_t *value);
+int fwts_inl(uint32_t port, uint32_t *value);
+
+int fwts_outb(uint32_t port, uint8_t value);
+int fwts_outw(uint32_t port, uint16_t value);
+int fwts_outl(uint32_t port, uint32_t value);
+
+#endif
diff --git a/src/lib/src/Makefile.am b/src/lib/src/Makefile.am
index a91d9ab..6a44641 100644
--- a/src/lib/src/Makefile.am
+++ b/src/lib/src/Makefile.am
@@ -44,6 +44,7 @@  libfwts_la_SOURCES = 		\
 	fwts_hwinfo.c 		\
 	fwts_iasl.c 		\
 	fwts_interactive.c 	\
+	fwts_ioport.c		\
 	fwts_keymap.c 		\
 	fwts_klog.c 		\
 	fwts_list.c 		\
diff --git a/src/lib/src/fwts_ioport.c b/src/lib/src/fwts_ioport.c
new file mode 100644
index 0000000..bc6243e
--- /dev/null
+++ b/src/lib/src/fwts_ioport.c
@@ -0,0 +1,136 @@ 
+/*
+ * Copyright (C) 2013 Canonical
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include <sys/io.h>
+#include <stdint.h>
+#include <signal.h>
+#include <setjmp.h>
+
+#include "fwts.h"
+
+static jmp_buf jmpbuf;
+
+/*
+ *  If we hit a SIGSEGV then the port read
+ *  failed and we longjmp back and return
+ *  FWTS_ERROR
+ */
+static void segv_handler(int dummy)
+{
+	FWTS_UNUSED(dummy);
+
+	signal(SIGSEGV, SIG_DFL);
+	longjmp(jmpbuf, 1);
+}
+
+/*
+ *  fwts_inb()
+ *	8 bit port read, handle access errors
+ */
+int fwts_inb(uint32_t port, uint8_t *value)
+{
+	if (setjmp(jmpbuf) != 0)
+		return FWTS_ERROR;
+
+	signal(SIGSEGV, segv_handler);
+	*value = inb(port);
+	signal(SIGSEGV, SIG_DFL);
+
+	return FWTS_OK;
+}
+
+/*
+ *  fwts_inw()
+ *	16 bit port read, handle access errors
+ */
+int fwts_inw(uint32_t port, uint16_t *value)
+{
+	if (setjmp(jmpbuf) != 0)
+		return FWTS_ERROR;
+
+	signal(SIGSEGV, segv_handler);
+	*value = inw(port);
+	signal(SIGSEGV, SIG_DFL);
+
+	return FWTS_OK;
+}
+
+/*
+ *  fwts_inl()
+ *	32 bit port read, handle access errors
+ */
+int fwts_inl(uint32_t port, uint32_t *value)
+{
+	if (setjmp(jmpbuf) != 0)
+		return FWTS_ERROR;
+
+	signal(SIGSEGV, segv_handler);
+	*value = inl(port);
+	signal(SIGSEGV, SIG_DFL);
+
+	return FWTS_OK;
+}
+
+/*
+ *  fwts_outb()
+ *	8 bit port write, handle access errors
+ */
+int fwts_outb(uint32_t port, uint8_t value)
+{
+	if (setjmp(jmpbuf) != 0)
+		return FWTS_ERROR;
+
+	signal(SIGSEGV, segv_handler);
+	outb(port, value);
+	signal(SIGSEGV, SIG_DFL);
+
+	return FWTS_OK;
+}
+
+/*
+ *  fwts_outw()
+ *	16 bit port write, handle access errors
+ */
+int fwts_outw(uint32_t port, uint16_t value)
+{
+	if (setjmp(jmpbuf) != 0)
+		return FWTS_ERROR;
+
+	signal(SIGSEGV, segv_handler);
+	outw(port, value);
+	signal(SIGSEGV, SIG_DFL);
+
+	return FWTS_OK;
+}
+
+/*
+ *  fwts_outl()
+ *	32 bit port write, handle access errors
+ */
+int fwts_outl(uint32_t port, uint32_t value)
+{
+	if (setjmp(jmpbuf) != 0)
+		return FWTS_ERROR;
+
+	signal(SIGSEGV, segv_handler);
+	outw(port, value);
+	signal(SIGSEGV, SIG_DFL);
+
+	return FWTS_OK;
+}