ACK: [PATCH] lib: fwts_acpi_tables: load tables from /sys (LP: #1437043)

[ivanhu]

On 2015年03月27日 08:57, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> The /dev/mem interface is going to be deprecated, so if we can't
> load directly from memory then try to load from the alternative
> /sys/firmware/acpi/tables raw ACPI tables.
>
> This will address issues on ARM first, and eventually x86 when
> the /dev/mem interface gets removed. I discovered this fact
> at the fw-summit today.
>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>   src/lib/src/fwts_acpi_tables.c | 69 ++++++++++++++++++++++++++++++++++++------
>   1 file changed, 60 insertions(+), 9 deletions(-)
>
> diff --git a/src/lib/src/fwts_acpi_tables.c b/src/lib/src/fwts_acpi_tables.c
> index 35d0414..d3ef6cd 100644
> --- a/src/lib/src/fwts_acpi_tables.c
> +++ b/src/lib/src/fwts_acpi_tables.c
> @@ -677,10 +677,17 @@ static uint8_t *fwts_acpi_load_table_from_file(const int fd, size_t *length)
>   	return ptr;
>   }
>   
> -static int fwts_acpi_load_tables_from_file(fwts_framework *fw)
> +/*
> + *  fwts_acpi_load_tables_from_file_generic()
> + *	load acpi tables from a given path with a given file extention
> + */
> +static int fwts_acpi_load_tables_from_file_generic(
> +	fwts_framework *fw,
> +	char *acpi_table_path,
> +	const char *extention,
> +	int *count)
>   {
>   	struct dirent **dir_entries;
> -	int count = 0;
>   	int i;
>   
>   	/*
> @@ -688,22 +695,38 @@ static int fwts_acpi_load_tables_from_file(fwts_framework *fw)
>   	 * to ensure the tables are always loaded into memory
>   	 * in some form of deterministic order
>   	 */
> -	if ((count = scandir(fw->acpi_table_path, &dir_entries, 0, alphasort)) < 0) {
> +	if ((*count = scandir(acpi_table_path, &dir_entries, 0, alphasort)) < 0) {
>   		fwts_log_error(fw, "Cannot open directory '%s' to read ACPI tables.",
>   			fw->acpi_table_path);
>   		return FWTS_ERROR;
>   	}
>   
> -	for (i = 0; i < count; i++) {
> -		if (strstr(dir_entries[i]->d_name, ".dat")) {
> +	for (i = 0; i < *count; i++) {
> +		/* Ignore . directories */
> +		if (dir_entries[i]->d_name[0] == '.')
> +			continue;
> +
> +		if (strstr(dir_entries[i]->d_name, extention)) {
>   			char path[PATH_MAX];
>   			int fd;
>   
>   			snprintf(path, sizeof(path), "%s/%s",
> -				fw->acpi_table_path, dir_entries[i]->d_name);
> +				acpi_table_path, dir_entries[i]->d_name);
>   			if ((fd = open(path, O_RDONLY)) >= 0) {
>   				uint8_t *table;
>   				size_t length;
> +				struct stat buf;
> +
> +				if (fstat(fd, &buf) < 0) {
> +					fwts_log_error(fw, "Cannot stat file '%s'\n", path);
> +					close(fd);
> +					continue;
> +				}
> +				/* Must be a regular file */
> +				if (!S_ISREG(buf.st_mode)) {
> +					close(fd);
> +					continue;
> +				}
>   
>   				if ((table = fwts_acpi_load_table_from_file(fd, &length)) != NULL) {
>   					char name[9];	/* "RSD PTR " or standard ACPI 4 letter name */
> @@ -749,12 +772,22 @@ static int fwts_acpi_load_tables_from_file(fwts_framework *fw)
>   		free(dir_entries[i]);
>   	}
>   	free(dir_entries);
> +	return FWTS_OK;
> +}
>   
> +/*
> + *  fwts_acpi_load_tables_from_file()
> + *	load raw acpi tables from a user given path, files must end in ".dat"
> + */
> +static int fwts_acpi_load_tables_from_file(fwts_framework *fw)
> +{
> +	int count;
> +
> +	fwts_acpi_load_tables_from_file_generic(fw, fw->acpi_table_path, ".dat", &count);
>   	if (count == 0) {
>   		fwts_log_error(fw, "Could not find any APCI tables in directory '%s'.\n", fw->acpi_table_path);
>   		return FWTS_ERROR;
>   	}
> -
>   	return FWTS_OK;
>   }
>   
> @@ -976,6 +1009,20 @@ static int fwts_acpi_load_tables_fixup(fwts_framework *fw)
>   	return FWTS_OK;
>   }
>   
> +
> +static int fwts_acpi_load_tables_from_sysfs(fwts_framework *fw)
> +{
> +	int count, total;
> +	fwts_acpi_load_tables_from_file_generic(fw, "/sys/firmware/acpi/tables", "", &total);
> +	fwts_acpi_load_tables_from_file_generic(fw, "/sys/firmware/acpi/tables/dynamic", "", &count);
> +	total += count;
> +	if (total == 0) {
> +		fwts_log_error(fw, "Could not find any APCI tables in directory '/sys/firmware/acpi/tables'.\n");
> +		return FWTS_ERROR;
> +	}
> +	return FWTS_OK;
> +}
> +
>   /*
>    *  fwts_acpi_load_tables()
>    *	Load from firmware or from files in a specified directory
> @@ -988,9 +1035,13 @@ int fwts_acpi_load_tables(fwts_framework *fw)
>   		ret = fwts_acpi_load_tables_from_file(fw);
>   	else if (fw->acpi_table_acpidump_file != NULL)
>   		ret = fwts_acpi_load_tables_from_acpidump(fw);
> -	else if (fwts_check_root_euid(fw, true) == FWTS_OK)
> +	else if (fwts_check_root_euid(fw, true) == FWTS_OK) {
>   		ret = fwts_acpi_load_tables_from_firmware(fw);
> -	else
> +
> +		/* Load from memory failed (e.g. no /dev/mem), so try sysfs */
> +		if (ret != FWTS_OK)
> +			ret = fwts_acpi_load_tables_from_sysfs(fw);
> +	} else
>   		ret = FWTS_ERROR_NO_PRIV;
>   
>   	if (ret == FWTS_OK) {

Acked-by: Ivan Hu <ivan.hu at canonical.com>