Patchwork dmi: dmi_decode: make advice more relevant to data handled by the kernel

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Submitter Colin King
Date July 17, 2012, 8:30 p.m.
Message ID <1342557023-24240-1-git-send-email-colin.king@canonical.com>
Download mbox | patch
Permalink /patch/171555/
State Accepted
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Comments

Colin King - July 17, 2012, 8:30 p.m.
From: Colin Ian King <colin.king@canonical.com>

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 src/dmi/dmi_decode/dmi_decode.c |  154 ++++++++++++++++++++++++++++++++-------
 1 file changed, 127 insertions(+), 27 deletions(-)
Ivan Hu - July 18, 2012, 8:19 a.m.
On 07/18/2012 04:30 AM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   src/dmi/dmi_decode/dmi_decode.c |  154 ++++++++++++++++++++++++++++++++-------
>   1 file changed, 127 insertions(+), 27 deletions(-)
>
> diff --git a/src/dmi/dmi_decode/dmi_decode.c b/src/dmi/dmi_decode/dmi_decode.c
> index d266bea..f80f1a9 100644
> --- a/src/dmi/dmi_decode/dmi_decode.c
> +++ b/src/dmi/dmi_decode/dmi_decode.c
> @@ -78,6 +78,11 @@ typedef struct {
>   	uint8_t   mapped;
>   } fwts_chassis_type_map;
>
> +typedef struct {
> +	uint8_t	type;
> +	uint8_t	offset;
> +} fwts_dmi_used_by_kernel;
> +
>   static const fwts_dmi_pattern dmi_patterns[] = {
>   	{ "DMISerialNumber",	"Serial Number", 	"0123456789" },
>   	{ "DMIAssetTag",	"Asset Tag",		"1234567890" },
> @@ -143,6 +148,62 @@ static const fwts_dmi_version dmi_versions[] = {
>   	{ 0, 0 }
>   };
>
> +#define FIELD_ANY	0xff
> +#define TYPE_EOD	0xff
> +
> +/*
> + *  DMI decoded fields used by the kernel, i.e. fields
> + *  we care that work,
> + *	see drivers/firmware/dmi_scan.c, dmi_decode()
> + */
> +static fwts_dmi_used_by_kernel dmi_used_by_kernel_table[] = {
> +	/* Type 0 BIOS Information fields */
> +	{ 0, 4 },
> +	{ 0, 5 },
> +	{ 0, 8 },
> +	/* Type 1, System Information */
> +	{ 1, 4 },
> +	{ 1, 5 },
> +	{ 1, 6 },
> +	{ 1, 7 },
> +	{ 1, 8 },
> +	/* Type 2, Base Board Information */
> +	{ 2, 4 },
> +	{ 2, 5 },
> +	{ 2, 6 },
> +	{ 2, 7 },
> +	{ 2, 8 },
> +	/* Type 3, Chassis Information */
> +	{ 3, 4 },
> +	{ 3, 5 },
> +	{ 3, 6 },
> +	{ 3, 7 },
> +	{ 3, 8 },
> +	/* Type 10, Onboard Devices Information */
> +	{ 10, FIELD_ANY },
> +	/* Type 11, OEM Strings */
> +	{ 11, FIELD_ANY },
> +	/* Type 38, IPMI Device Information */
> +	{ 38, FIELD_ANY },
> +	/* Type 41, Onboard Devices Extended Information */
> +	{ 41, FIELD_ANY },
> +	/* End */
> +	{ TYPE_EOD, 0xff },
> +};
> +
> +static bool dmi_used_by_kernel(uint8_t type, uint8_t offset)
> +{
> +	int i;
> +
> +	for (i = 0; dmi_used_by_kernel_table[i].type != TYPE_EOD; i++) {
> +		if (dmi_used_by_kernel_table[i].type == type)
> +			if ((dmi_used_by_kernel_table[i].offset == FIELD_ANY) ||
> +			    (dmi_used_by_kernel_table[i].offset == offset))
> +				return true;
> +	}
> +	return false;
> +}
> +
>   static uint16_t dmi_remap_version(fwts_framework *fw, uint16_t old)
>   {
>   	int i;
> @@ -162,15 +223,21 @@ static uint16_t dmi_remap_version(fwts_framework *fw, uint16_t old)
>   	return old;
>   }
>
> -static void dmi_out_of_range_advice(fwts_framework *fw)
> +static void dmi_out_of_range_advice(fwts_framework *fw, uint8_t type, uint8_t offset)
>   {
> -	fwts_advice(fw,
> -		"A value that is out of range is incorrect and not conforming to "
> -		"the SMBIOS specification.  It is possible that it "
> -		"won't be handled correctly by the operating system or by tools "
> -		"like dmidecode. For some fields this out of range setings "
> -		"could lead to the operating system to ignore or misunderstand this "
> -		"particular SMBIOS configuration.");
> +	if (dmi_used_by_kernel(type, offset))
> +		fwts_advice(fw,
> +			"A value that is out of range is incorrect and not conforming to "
> +			"the SMBIOS specification.  The Linux kernel extracts and uses "
> +			"this particular data item, so it is recommended that this SMBIOS "
> +			"configuration is corrected even if the impact on the system "
> +			"is most probably not critical.");
> +	else
> +		fwts_advice(fw,
> +			"A value that is out of range is incorrect and not conforming to "
> +			"the SMBIOS specification.  This field is not currently used by "
> +			"the Linux kernel, so this firmware bug shouldn't cause any "
> +			"problems.");
>   }
>
>   static void dmi_min_max_uint8_check(fwts_framework *fw,
> @@ -189,7 +256,7 @@ static void dmi_min_max_uint8_check(fwts_framework *fw,
>   			"Out of range value 0x%2.2x (range allowed 0x%2.2x..0x%2.2x) "
>   			"while accessing entry '%s' @ 0x%8.8x, field '%s', offset 0x%2.2x",
>   			val, min, max, table, addr, field, offset);
> -		dmi_out_of_range_advice(fw);
> +		dmi_out_of_range_advice(fw, hdr->type, offset);
>   	}
>   }
>
> @@ -211,7 +278,7 @@ static void dmi_min_max_mask_uint8_check(fwts_framework *fw,
>   			"Out of range value 0x%2.2x (range allowed 0x%2.2x..0x%2.2x) "
>   			"while accessing entry '%s' @ 0x%8.8x, field '%s', offset 0x%2.2x",
>   			val, min, max, table, addr, field, offset);
> -		dmi_out_of_range_advice(fw);
> +		dmi_out_of_range_advice(fw, hdr->type, offset);
>   	}
>   }
>
> @@ -237,15 +304,29 @@ static void dmi_str_check_index(fwts_framework *fw,
>   		}
>   		/* Sanity checks */
>   		if (*data == '\0') {
> +			/* This entry is clearly broken so flag it as a corrupt entry */
>   			fwts_failed(fw, LOG_LEVEL_HIGH, DMI_STRING_INDEX_OUT_OF_RANGE,
>   				"Out of range string index 0x%2.2x while accessing entry '%s' "
>   				"@ 0x%8.8x, field '%s', offset 0x%2.2x",
>   				index, table, addr, field, offset);
> -			fwts_advice(fw,
> -				"DMI strings are stored in a manner that uses a special "
> -				"index to fetch the Nth string from the data. For this "
> -				"particular DMI string the index given is not in range "
> -				"which means this particular entry is broken.");
> +			if (dmi_used_by_kernel(hdr->type, offset))
> +				fwts_advice(fw,
> +					"DMI strings are stored in a manner that uses a special "
> +					"index to fetch the Nth string from the data. For this "
> +					"particular DMI string the index given is not in range "
> +					"which means this particular entry is broken. The Linux "
> +					"kernel uses this string - hence this string should be "
> +					"fixed to ensure sane data is passed to the kernel. "
> +					"Note that this probably won't cause any critical system "
> +					"errors.");
> +			else
> +				fwts_advice(fw,
> +					"DMI strings are stored in a manner that uses a special "
> +					"index to fetch the Nth string from the data. For this "
> +					"particular DMI string the index given is not in range "
> +					"which means this particular entry is broken. The Linux "
> +					"kernel does not use this string, so this error will not "
> +					"cause any system errors.");
>   			return;
>   		}
>
> @@ -262,18 +343,37 @@ static void dmi_str_check_index(fwts_framework *fw,
>   			}
>   		}
>   		if (failed != -1) {
> -			fwts_failed(fw, LOG_LEVEL_LOW, dmi_patterns[j].label,
> -				"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> -				"offset 0x%2.2x has a default value '%s' and probably has "
> -				"not been updated by the BIOS vendor.",
> -				index, table, addr, field, offset, data);
> -			fwts_advice(fw,
> -				"The DMI table contains data which is clearly been "
> -				"left in a default setting and not been configured "
> -				"for this machine.  While this is not critical it does "
> -				"mean that somebody has probably forgotten to define this "
> -				"field and it basically means this field is effectively "
> -				"useless.");
> +			if (dmi_used_by_kernel(hdr->type, offset)) {
> +				fwts_failed(fw, LOG_LEVEL_MEDIUM, dmi_patterns[j].label,
> +					"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> +					"offset 0x%2.2x has a default value '%s' and probably has "
> +					"not been updated by the BIOS vendor.",
> +					index, table, addr, field, offset, data);
> +				fwts_advice(fw,
> +					"The DMI table contains data which is clearly been "
> +					"left in a default setting and not been configured "
> +					"for this machine. "
> +					"Somebody has probably forgotten to define this "
> +					"field and it basically means this field is effectively "
> +					"useless. Note that the kernel uses this field so "
> +					"it probably should be corrected to ensure the kernel "
> +					"is using sane values.");
> +			} else {
> +				/* This string is broken, but we don't care about it too much */
> +				fwts_failed(fw, LOG_LEVEL_LOW, dmi_patterns[j].label,
> +					"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> +					"offset 0x%2.2x has a default value '%s' and probably has "
> +					"not been updated by the BIOS vendor.",
> +					index, table, addr, field, offset, data);
> +				fwts_advice(fw,
> +					"The DMI table contains data which is clearly been "
> +					"left in a default setting and not been configured "
> +					"for this machine. "
> +					"Somebody has probably forgotten to define this "
> +					"field and it basically means this field is effectively "
> +					"useless, however the kernel does not use this data "
> +					"so the issue is fairly low.");
> +			}
>   		}
>   	}
>   }
>
Acked-by: Ivan Hu<ivan.hu@canonical.com>
Keng-Yu Lin - July 19, 2012, 7:10 a.m.
On Wed, Jul 18, 2012 at 4:30 AM, Colin King <colin.king@canonical.com> wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  src/dmi/dmi_decode/dmi_decode.c |  154 ++++++++++++++++++++++++++++++++-------
>  1 file changed, 127 insertions(+), 27 deletions(-)
>
> diff --git a/src/dmi/dmi_decode/dmi_decode.c b/src/dmi/dmi_decode/dmi_decode.c
> index d266bea..f80f1a9 100644
> --- a/src/dmi/dmi_decode/dmi_decode.c
> +++ b/src/dmi/dmi_decode/dmi_decode.c
> @@ -78,6 +78,11 @@ typedef struct {
>         uint8_t   mapped;
>  } fwts_chassis_type_map;
>
> +typedef struct {
> +       uint8_t type;
> +       uint8_t offset;
> +} fwts_dmi_used_by_kernel;
> +
>  static const fwts_dmi_pattern dmi_patterns[] = {
>         { "DMISerialNumber",    "Serial Number",        "0123456789" },
>         { "DMIAssetTag",        "Asset Tag",            "1234567890" },
> @@ -143,6 +148,62 @@ static const fwts_dmi_version dmi_versions[] = {
>         { 0, 0 }
>  };
>
> +#define FIELD_ANY      0xff
> +#define TYPE_EOD       0xff
> +
> +/*
> + *  DMI decoded fields used by the kernel, i.e. fields
> + *  we care that work,
> + *     see drivers/firmware/dmi_scan.c, dmi_decode()
> + */
> +static fwts_dmi_used_by_kernel dmi_used_by_kernel_table[] = {
> +       /* Type 0 BIOS Information fields */
> +       { 0, 4 },
> +       { 0, 5 },
> +       { 0, 8 },
> +       /* Type 1, System Information */
> +       { 1, 4 },
> +       { 1, 5 },
> +       { 1, 6 },
> +       { 1, 7 },
> +       { 1, 8 },
> +       /* Type 2, Base Board Information */
> +       { 2, 4 },
> +       { 2, 5 },
> +       { 2, 6 },
> +       { 2, 7 },
> +       { 2, 8 },
> +       /* Type 3, Chassis Information */
> +       { 3, 4 },
> +       { 3, 5 },
> +       { 3, 6 },
> +       { 3, 7 },
> +       { 3, 8 },
> +       /* Type 10, Onboard Devices Information */
> +       { 10, FIELD_ANY },
> +       /* Type 11, OEM Strings */
> +       { 11, FIELD_ANY },
> +       /* Type 38, IPMI Device Information */
> +       { 38, FIELD_ANY },
> +       /* Type 41, Onboard Devices Extended Information */
> +       { 41, FIELD_ANY },
> +       /* End */
> +       { TYPE_EOD, 0xff },
> +};
> +
> +static bool dmi_used_by_kernel(uint8_t type, uint8_t offset)
> +{
> +       int i;
> +
> +       for (i = 0; dmi_used_by_kernel_table[i].type != TYPE_EOD; i++) {
> +               if (dmi_used_by_kernel_table[i].type == type)
> +                       if ((dmi_used_by_kernel_table[i].offset == FIELD_ANY) ||
> +                           (dmi_used_by_kernel_table[i].offset == offset))
> +                               return true;
> +       }
> +       return false;
> +}
> +
>  static uint16_t dmi_remap_version(fwts_framework *fw, uint16_t old)
>  {
>         int i;
> @@ -162,15 +223,21 @@ static uint16_t dmi_remap_version(fwts_framework *fw, uint16_t old)
>         return old;
>  }
>
> -static void dmi_out_of_range_advice(fwts_framework *fw)
> +static void dmi_out_of_range_advice(fwts_framework *fw, uint8_t type, uint8_t offset)
>  {
> -       fwts_advice(fw,
> -               "A value that is out of range is incorrect and not conforming to "
> -               "the SMBIOS specification.  It is possible that it "
> -               "won't be handled correctly by the operating system or by tools "
> -               "like dmidecode. For some fields this out of range setings "
> -               "could lead to the operating system to ignore or misunderstand this "
> -               "particular SMBIOS configuration.");
> +       if (dmi_used_by_kernel(type, offset))
> +               fwts_advice(fw,
> +                       "A value that is out of range is incorrect and not conforming to "
> +                       "the SMBIOS specification.  The Linux kernel extracts and uses "
> +                       "this particular data item, so it is recommended that this SMBIOS "
> +                       "configuration is corrected even if the impact on the system "
> +                       "is most probably not critical.");
> +       else
> +               fwts_advice(fw,
> +                       "A value that is out of range is incorrect and not conforming to "
> +                       "the SMBIOS specification.  This field is not currently used by "
> +                       "the Linux kernel, so this firmware bug shouldn't cause any "
> +                       "problems.");
>  }
>
>  static void dmi_min_max_uint8_check(fwts_framework *fw,
> @@ -189,7 +256,7 @@ static void dmi_min_max_uint8_check(fwts_framework *fw,
>                         "Out of range value 0x%2.2x (range allowed 0x%2.2x..0x%2.2x) "
>                         "while accessing entry '%s' @ 0x%8.8x, field '%s', offset 0x%2.2x",
>                         val, min, max, table, addr, field, offset);
> -               dmi_out_of_range_advice(fw);
> +               dmi_out_of_range_advice(fw, hdr->type, offset);
>         }
>  }
>
> @@ -211,7 +278,7 @@ static void dmi_min_max_mask_uint8_check(fwts_framework *fw,
>                         "Out of range value 0x%2.2x (range allowed 0x%2.2x..0x%2.2x) "
>                         "while accessing entry '%s' @ 0x%8.8x, field '%s', offset 0x%2.2x",
>                         val, min, max, table, addr, field, offset);
> -               dmi_out_of_range_advice(fw);
> +               dmi_out_of_range_advice(fw, hdr->type, offset);
>         }
>  }
>
> @@ -237,15 +304,29 @@ static void dmi_str_check_index(fwts_framework *fw,
>                 }
>                 /* Sanity checks */
>                 if (*data == '\0') {
> +                       /* This entry is clearly broken so flag it as a corrupt entry */
>                         fwts_failed(fw, LOG_LEVEL_HIGH, DMI_STRING_INDEX_OUT_OF_RANGE,
>                                 "Out of range string index 0x%2.2x while accessing entry '%s' "
>                                 "@ 0x%8.8x, field '%s', offset 0x%2.2x",
>                                 index, table, addr, field, offset);
> -                       fwts_advice(fw,
> -                               "DMI strings are stored in a manner that uses a special "
> -                               "index to fetch the Nth string from the data. For this "
> -                               "particular DMI string the index given is not in range "
> -                               "which means this particular entry is broken.");
> +                       if (dmi_used_by_kernel(hdr->type, offset))
> +                               fwts_advice(fw,
> +                                       "DMI strings are stored in a manner that uses a special "
> +                                       "index to fetch the Nth string from the data. For this "
> +                                       "particular DMI string the index given is not in range "
> +                                       "which means this particular entry is broken. The Linux "
> +                                       "kernel uses this string - hence this string should be "
> +                                       "fixed to ensure sane data is passed to the kernel. "
> +                                       "Note that this probably won't cause any critical system "
> +                                       "errors.");
> +                       else
> +                               fwts_advice(fw,
> +                                       "DMI strings are stored in a manner that uses a special "
> +                                       "index to fetch the Nth string from the data. For this "
> +                                       "particular DMI string the index given is not in range "
> +                                       "which means this particular entry is broken. The Linux "
> +                                       "kernel does not use this string, so this error will not "
> +                                       "cause any system errors.");
>                         return;
>                 }
>
> @@ -262,18 +343,37 @@ static void dmi_str_check_index(fwts_framework *fw,
>                         }
>                 }
>                 if (failed != -1) {
> -                       fwts_failed(fw, LOG_LEVEL_LOW, dmi_patterns[j].label,
> -                               "String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> -                               "offset 0x%2.2x has a default value '%s' and probably has "
> -                               "not been updated by the BIOS vendor.",
> -                               index, table, addr, field, offset, data);
> -                       fwts_advice(fw,
> -                               "The DMI table contains data which is clearly been "
> -                               "left in a default setting and not been configured "
> -                               "for this machine.  While this is not critical it does "
> -                               "mean that somebody has probably forgotten to define this "
> -                               "field and it basically means this field is effectively "
> -                               "useless.");
> +                       if (dmi_used_by_kernel(hdr->type, offset)) {
> +                               fwts_failed(fw, LOG_LEVEL_MEDIUM, dmi_patterns[j].label,
> +                                       "String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> +                                       "offset 0x%2.2x has a default value '%s' and probably has "
> +                                       "not been updated by the BIOS vendor.",
> +                                       index, table, addr, field, offset, data);
> +                               fwts_advice(fw,
> +                                       "The DMI table contains data which is clearly been "
> +                                       "left in a default setting and not been configured "
> +                                       "for this machine. "
> +                                       "Somebody has probably forgotten to define this "
> +                                       "field and it basically means this field is effectively "
> +                                       "useless. Note that the kernel uses this field so "
> +                                       "it probably should be corrected to ensure the kernel "
> +                                       "is using sane values.");
> +                       } else {
> +                               /* This string is broken, but we don't care about it too much */
> +                               fwts_failed(fw, LOG_LEVEL_LOW, dmi_patterns[j].label,
> +                                       "String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> +                                       "offset 0x%2.2x has a default value '%s' and probably has "
> +                                       "not been updated by the BIOS vendor.",
> +                                       index, table, addr, field, offset, data);
> +                               fwts_advice(fw,
> +                                       "The DMI table contains data which is clearly been "
> +                                       "left in a default setting and not been configured "
> +                                       "for this machine. "
> +                                       "Somebody has probably forgotten to define this "
> +                                       "field and it basically means this field is effectively "
> +                                       "useless, however the kernel does not use this data "
> +                                       "so the issue is fairly low.");
> +                       }
>                 }
>         }
>  }
> --
> 1.7.10.4
>
Acked-by: Keng-Yu Lin <kengyu@canonical.com>
Alex Hung - July 19, 2012, 7:12 a.m.
On 07/18/2012 04:30 AM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   src/dmi/dmi_decode/dmi_decode.c |  154 ++++++++++++++++++++++++++++++++-------
>   1 file changed, 127 insertions(+), 27 deletions(-)
>
> diff --git a/src/dmi/dmi_decode/dmi_decode.c b/src/dmi/dmi_decode/dmi_decode.c
> index d266bea..f80f1a9 100644
> --- a/src/dmi/dmi_decode/dmi_decode.c
> +++ b/src/dmi/dmi_decode/dmi_decode.c
> @@ -78,6 +78,11 @@ typedef struct {
>   	uint8_t   mapped;
>   } fwts_chassis_type_map;
>
> +typedef struct {
> +	uint8_t	type;
> +	uint8_t	offset;
> +} fwts_dmi_used_by_kernel;
> +
>   static const fwts_dmi_pattern dmi_patterns[] = {
>   	{ "DMISerialNumber",	"Serial Number", 	"0123456789" },
>   	{ "DMIAssetTag",	"Asset Tag",		"1234567890" },
> @@ -143,6 +148,62 @@ static const fwts_dmi_version dmi_versions[] = {
>   	{ 0, 0 }
>   };
>
> +#define FIELD_ANY	0xff
> +#define TYPE_EOD	0xff
> +
> +/*
> + *  DMI decoded fields used by the kernel, i.e. fields
> + *  we care that work,
> + *	see drivers/firmware/dmi_scan.c, dmi_decode()
> + */
> +static fwts_dmi_used_by_kernel dmi_used_by_kernel_table[] = {
> +	/* Type 0 BIOS Information fields */
> +	{ 0, 4 },
> +	{ 0, 5 },
> +	{ 0, 8 },
> +	/* Type 1, System Information */
> +	{ 1, 4 },
> +	{ 1, 5 },
> +	{ 1, 6 },
> +	{ 1, 7 },
> +	{ 1, 8 },
> +	/* Type 2, Base Board Information */
> +	{ 2, 4 },
> +	{ 2, 5 },
> +	{ 2, 6 },
> +	{ 2, 7 },
> +	{ 2, 8 },
> +	/* Type 3, Chassis Information */
> +	{ 3, 4 },
> +	{ 3, 5 },
> +	{ 3, 6 },
> +	{ 3, 7 },
> +	{ 3, 8 },
> +	/* Type 10, Onboard Devices Information */
> +	{ 10, FIELD_ANY },
> +	/* Type 11, OEM Strings */
> +	{ 11, FIELD_ANY },
> +	/* Type 38, IPMI Device Information */
> +	{ 38, FIELD_ANY },
> +	/* Type 41, Onboard Devices Extended Information */
> +	{ 41, FIELD_ANY },
> +	/* End */
> +	{ TYPE_EOD, 0xff },
> +};
> +
> +static bool dmi_used_by_kernel(uint8_t type, uint8_t offset)
> +{
> +	int i;
> +
> +	for (i = 0; dmi_used_by_kernel_table[i].type != TYPE_EOD; i++) {
> +		if (dmi_used_by_kernel_table[i].type == type)
> +			if ((dmi_used_by_kernel_table[i].offset == FIELD_ANY) ||
> +			    (dmi_used_by_kernel_table[i].offset == offset))
> +				return true;
> +	}
> +	return false;
> +}
> +
>   static uint16_t dmi_remap_version(fwts_framework *fw, uint16_t old)
>   {
>   	int i;
> @@ -162,15 +223,21 @@ static uint16_t dmi_remap_version(fwts_framework *fw, uint16_t old)
>   	return old;
>   }
>
> -static void dmi_out_of_range_advice(fwts_framework *fw)
> +static void dmi_out_of_range_advice(fwts_framework *fw, uint8_t type, uint8_t offset)
>   {
> -	fwts_advice(fw,
> -		"A value that is out of range is incorrect and not conforming to "
> -		"the SMBIOS specification.  It is possible that it "
> -		"won't be handled correctly by the operating system or by tools "
> -		"like dmidecode. For some fields this out of range setings "
> -		"could lead to the operating system to ignore or misunderstand this "
> -		"particular SMBIOS configuration.");
> +	if (dmi_used_by_kernel(type, offset))
> +		fwts_advice(fw,
> +			"A value that is out of range is incorrect and not conforming to "
> +			"the SMBIOS specification.  The Linux kernel extracts and uses "
> +			"this particular data item, so it is recommended that this SMBIOS "
> +			"configuration is corrected even if the impact on the system "
> +			"is most probably not critical.");
> +	else
> +		fwts_advice(fw,
> +			"A value that is out of range is incorrect and not conforming to "
> +			"the SMBIOS specification.  This field is not currently used by "
> +			"the Linux kernel, so this firmware bug shouldn't cause any "
> +			"problems.");
>   }
>
>   static void dmi_min_max_uint8_check(fwts_framework *fw,
> @@ -189,7 +256,7 @@ static void dmi_min_max_uint8_check(fwts_framework *fw,
>   			"Out of range value 0x%2.2x (range allowed 0x%2.2x..0x%2.2x) "
>   			"while accessing entry '%s' @ 0x%8.8x, field '%s', offset 0x%2.2x",
>   			val, min, max, table, addr, field, offset);
> -		dmi_out_of_range_advice(fw);
> +		dmi_out_of_range_advice(fw, hdr->type, offset);
>   	}
>   }
>
> @@ -211,7 +278,7 @@ static void dmi_min_max_mask_uint8_check(fwts_framework *fw,
>   			"Out of range value 0x%2.2x (range allowed 0x%2.2x..0x%2.2x) "
>   			"while accessing entry '%s' @ 0x%8.8x, field '%s', offset 0x%2.2x",
>   			val, min, max, table, addr, field, offset);
> -		dmi_out_of_range_advice(fw);
> +		dmi_out_of_range_advice(fw, hdr->type, offset);
>   	}
>   }
>
> @@ -237,15 +304,29 @@ static void dmi_str_check_index(fwts_framework *fw,
>   		}
>   		/* Sanity checks */
>   		if (*data == '\0') {
> +			/* This entry is clearly broken so flag it as a corrupt entry */
>   			fwts_failed(fw, LOG_LEVEL_HIGH, DMI_STRING_INDEX_OUT_OF_RANGE,
>   				"Out of range string index 0x%2.2x while accessing entry '%s' "
>   				"@ 0x%8.8x, field '%s', offset 0x%2.2x",
>   				index, table, addr, field, offset);
> -			fwts_advice(fw,
> -				"DMI strings are stored in a manner that uses a special "
> -				"index to fetch the Nth string from the data. For this "
> -				"particular DMI string the index given is not in range "
> -				"which means this particular entry is broken.");
> +			if (dmi_used_by_kernel(hdr->type, offset))
> +				fwts_advice(fw,
> +					"DMI strings are stored in a manner that uses a special "
> +					"index to fetch the Nth string from the data. For this "
> +					"particular DMI string the index given is not in range "
> +					"which means this particular entry is broken. The Linux "
> +					"kernel uses this string - hence this string should be "
> +					"fixed to ensure sane data is passed to the kernel. "
> +					"Note that this probably won't cause any critical system "
> +					"errors.");
> +			else
> +				fwts_advice(fw,
> +					"DMI strings are stored in a manner that uses a special "
> +					"index to fetch the Nth string from the data. For this "
> +					"particular DMI string the index given is not in range "
> +					"which means this particular entry is broken. The Linux "
> +					"kernel does not use this string, so this error will not "
> +					"cause any system errors.");
>   			return;
>   		}
>
> @@ -262,18 +343,37 @@ static void dmi_str_check_index(fwts_framework *fw,
>   			}
>   		}
>   		if (failed != -1) {
> -			fwts_failed(fw, LOG_LEVEL_LOW, dmi_patterns[j].label,
> -				"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> -				"offset 0x%2.2x has a default value '%s' and probably has "
> -				"not been updated by the BIOS vendor.",
> -				index, table, addr, field, offset, data);
> -			fwts_advice(fw,
> -				"The DMI table contains data which is clearly been "
> -				"left in a default setting and not been configured "
> -				"for this machine.  While this is not critical it does "
> -				"mean that somebody has probably forgotten to define this "
> -				"field and it basically means this field is effectively "
> -				"useless.");
> +			if (dmi_used_by_kernel(hdr->type, offset)) {
> +				fwts_failed(fw, LOG_LEVEL_MEDIUM, dmi_patterns[j].label,
> +					"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> +					"offset 0x%2.2x has a default value '%s' and probably has "
> +					"not been updated by the BIOS vendor.",
> +					index, table, addr, field, offset, data);
> +				fwts_advice(fw,
> +					"The DMI table contains data which is clearly been "
> +					"left in a default setting and not been configured "
> +					"for this machine. "
> +					"Somebody has probably forgotten to define this "
> +					"field and it basically means this field is effectively "
> +					"useless. Note that the kernel uses this field so "
> +					"it probably should be corrected to ensure the kernel "
> +					"is using sane values.");
> +			} else {
> +				/* This string is broken, but we don't care about it too much */
> +				fwts_failed(fw, LOG_LEVEL_LOW, dmi_patterns[j].label,
> +					"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
> +					"offset 0x%2.2x has a default value '%s' and probably has "
> +					"not been updated by the BIOS vendor.",
> +					index, table, addr, field, offset, data);
> +				fwts_advice(fw,
> +					"The DMI table contains data which is clearly been "
> +					"left in a default setting and not been configured "
> +					"for this machine. "
> +					"Somebody has probably forgotten to define this "
> +					"field and it basically means this field is effectively "
> +					"useless, however the kernel does not use this data "
> +					"so the issue is fairly low.");
> +			}
>   		}
>   	}
>   }
>
Acked-by: Alex Hung <alex.hung@canonical.com>

Patch

diff --git a/src/dmi/dmi_decode/dmi_decode.c b/src/dmi/dmi_decode/dmi_decode.c
index d266bea..f80f1a9 100644
--- a/src/dmi/dmi_decode/dmi_decode.c
+++ b/src/dmi/dmi_decode/dmi_decode.c
@@ -78,6 +78,11 @@  typedef struct {
 	uint8_t   mapped;
 } fwts_chassis_type_map;
 
+typedef struct {
+	uint8_t	type;
+	uint8_t	offset;
+} fwts_dmi_used_by_kernel;
+
 static const fwts_dmi_pattern dmi_patterns[] = {
 	{ "DMISerialNumber",	"Serial Number", 	"0123456789" },
 	{ "DMIAssetTag",	"Asset Tag",		"1234567890" },
@@ -143,6 +148,62 @@  static const fwts_dmi_version dmi_versions[] = {
 	{ 0, 0 }
 };
 
+#define FIELD_ANY	0xff
+#define TYPE_EOD	0xff
+
+/*
+ *  DMI decoded fields used by the kernel, i.e. fields
+ *  we care that work,
+ *	see drivers/firmware/dmi_scan.c, dmi_decode()
+ */
+static fwts_dmi_used_by_kernel dmi_used_by_kernel_table[] = {
+	/* Type 0 BIOS Information fields */
+	{ 0, 4 },
+	{ 0, 5 },
+	{ 0, 8 },
+	/* Type 1, System Information */
+	{ 1, 4 },
+	{ 1, 5 },
+	{ 1, 6 },
+	{ 1, 7 },
+	{ 1, 8 },
+	/* Type 2, Base Board Information */
+	{ 2, 4 },
+	{ 2, 5 },
+	{ 2, 6 },
+	{ 2, 7 },
+	{ 2, 8 },
+	/* Type 3, Chassis Information */
+	{ 3, 4 },
+	{ 3, 5 },
+	{ 3, 6 },
+	{ 3, 7 },
+	{ 3, 8 },
+	/* Type 10, Onboard Devices Information */
+	{ 10, FIELD_ANY },
+	/* Type 11, OEM Strings */
+	{ 11, FIELD_ANY },
+	/* Type 38, IPMI Device Information */
+	{ 38, FIELD_ANY },
+	/* Type 41, Onboard Devices Extended Information */
+	{ 41, FIELD_ANY },
+	/* End */
+	{ TYPE_EOD, 0xff },
+};
+
+static bool dmi_used_by_kernel(uint8_t type, uint8_t offset)
+{
+	int i;
+
+	for (i = 0; dmi_used_by_kernel_table[i].type != TYPE_EOD; i++) {
+		if (dmi_used_by_kernel_table[i].type == type)
+			if ((dmi_used_by_kernel_table[i].offset == FIELD_ANY) ||
+			    (dmi_used_by_kernel_table[i].offset == offset))
+				return true;
+	}
+	return false;
+}
+
 static uint16_t dmi_remap_version(fwts_framework *fw, uint16_t old)
 {
 	int i;
@@ -162,15 +223,21 @@  static uint16_t dmi_remap_version(fwts_framework *fw, uint16_t old)
 	return old;
 }

-static void dmi_out_of_range_advice(fwts_framework *fw)
+static void dmi_out_of_range_advice(fwts_framework *fw, uint8_t type, uint8_t offset)
 {
-	fwts_advice(fw,
-		"A value that is out of range is incorrect and not conforming to "
-		"the SMBIOS specification.  It is possible that it "
-		"won't be handled correctly by the operating system or by tools "
-		"like dmidecode. For some fields this out of range setings "
-		"could lead to the operating system to ignore or misunderstand this "
-		"particular SMBIOS configuration.");
+	if (dmi_used_by_kernel(type, offset))
+		fwts_advice(fw,
+			"A value that is out of range is incorrect and not conforming to "
+			"the SMBIOS specification.  The Linux kernel extracts and uses "
+			"this particular data item, so it is recommended that this SMBIOS "
+			"configuration is corrected even if the impact on the system "
+			"is most probably not critical.");
+	else
+		fwts_advice(fw,
+			"A value that is out of range is incorrect and not conforming to "
+			"the SMBIOS specification.  This field is not currently used by "
+			"the Linux kernel, so this firmware bug shouldn't cause any "
+			"problems.");
 }

 static void dmi_min_max_uint8_check(fwts_framework *fw,
@@ -189,7 +256,7 @@  static void dmi_min_max_uint8_check(fwts_framework *fw,
 			"Out of range value 0x%2.2x (range allowed 0x%2.2x..0x%2.2x) "
 			"while accessing entry '%s' @ 0x%8.8x, field '%s', offset 0x%2.2x",
 			val, min, max, table, addr, field, offset);
-		dmi_out_of_range_advice(fw);
+		dmi_out_of_range_advice(fw, hdr->type, offset);
 	}
 }

@@ -211,7 +278,7 @@  static void dmi_min_max_mask_uint8_check(fwts_framework *fw,
 			"Out of range value 0x%2.2x (range allowed 0x%2.2x..0x%2.2x) "
 			"while accessing entry '%s' @ 0x%8.8x, field '%s', offset 0x%2.2x",
 			val, min, max, table, addr, field, offset);
-		dmi_out_of_range_advice(fw);
+		dmi_out_of_range_advice(fw, hdr->type, offset);
 	}
 }

@@ -237,15 +304,29 @@  static void dmi_str_check_index(fwts_framework *fw,
 		}
 		/* Sanity checks */
 		if (*data == '\0') {
+			/* This entry is clearly broken so flag it as a corrupt entry */
 			fwts_failed(fw, LOG_LEVEL_HIGH, DMI_STRING_INDEX_OUT_OF_RANGE,
 				"Out of range string index 0x%2.2x while accessing entry '%s' "
 				"@ 0x%8.8x, field '%s', offset 0x%2.2x",
 				index, table, addr, field, offset);
-			fwts_advice(fw,
-				"DMI strings are stored in a manner that uses a special "
-				"index to fetch the Nth string from the data. For this "
-				"particular DMI string the index given is not in range "
-				"which means this particular entry is broken.");
+			if (dmi_used_by_kernel(hdr->type, offset))
+				fwts_advice(fw,
+					"DMI strings are stored in a manner that uses a special "
+					"index to fetch the Nth string from the data. For this "
+					"particular DMI string the index given is not in range "
+					"which means this particular entry is broken. The Linux "
+					"kernel uses this string - hence this string should be "
+					"fixed to ensure sane data is passed to the kernel. "
+					"Note that this probably won't cause any critical system "
+					"errors.");
+			else
+				fwts_advice(fw,
+					"DMI strings are stored in a manner that uses a special "
+					"index to fetch the Nth string from the data. For this "
+					"particular DMI string the index given is not in range "
+					"which means this particular entry is broken. The Linux "
+					"kernel does not use this string, so this error will not "
+					"cause any system errors.");
 			return;
 		}

@@ -262,18 +343,37 @@  static void dmi_str_check_index(fwts_framework *fw,
 			}
 		}
 		if (failed != -1) {
-			fwts_failed(fw, LOG_LEVEL_LOW, dmi_patterns[j].label,
-				"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
-				"offset 0x%2.2x has a default value '%s' and probably has "
-				"not been updated by the BIOS vendor.",
-				index, table, addr, field, offset, data);
-			fwts_advice(fw,
-				"The DMI table contains data which is clearly been "
-				"left in a default setting and not been configured "
-				"for this machine.  While this is not critical it does "
-				"mean that somebody has probably forgotten to define this "
-				"field and it basically means this field is effectively "
-				"useless.");
+			if (dmi_used_by_kernel(hdr->type, offset)) {
+				fwts_failed(fw, LOG_LEVEL_MEDIUM, dmi_patterns[j].label,
+					"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
+					"offset 0x%2.2x has a default value '%s' and probably has "
+					"not been updated by the BIOS vendor.",
+					index, table, addr, field, offset, data);
+				fwts_advice(fw,
+					"The DMI table contains data which is clearly been "
+					"left in a default setting and not been configured "
+					"for this machine. "
+					"Somebody has probably forgotten to define this "
+					"field and it basically means this field is effectively "
+					"useless. Note that the kernel uses this field so "
+					"it probably should be corrected to ensure the kernel "
+					"is using sane values.");
+			} else {
+				/* This string is broken, but we don't care about it too much */
+				fwts_failed(fw, LOG_LEVEL_LOW, dmi_patterns[j].label,
+					"String index 0x%2.2x in table entry '%s' @ 0x%8.8x, field '%s', "
+					"offset 0x%2.2x has a default value '%s' and probably has "
+					"not been updated by the BIOS vendor.",
+					index, table, addr, field, offset, data);
+				fwts_advice(fw,
+					"The DMI table contains data which is clearly been "
+					"left in a default setting and not been configured "
+					"for this machine. "
+					"Somebody has probably forgotten to define this "
+					"field and it basically means this field is effectively "
+					"useless, however the kernel does not use this data "
+					"so the issue is fairly low.");
+			}
 		}
 	}
 }