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

[Alex Hung]

On 01/15/2013 04:25 AM, Colin King wrote:
> From: Colin Ian King <colin.king at 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 at 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.