From 6ebf9136ec24c03f6ebeb6ec6d684ce55c2a4320 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Mon, 29 Jan 2024 14:09:36 +0100 Subject: smbios: if a string value is unknown, use string number 0 The SMBIOS specification describes: "If a string field references no string, a null (0) is placed in that string field." Accordingly we should avoid writing a string "Unknown" to the SMBIOS table. dmidecode displays 'Not Specified' if the string number is 0. Commit 00a871d34e2f ("smbios: empty strings in smbios_add_string()") correctly identified that strings may not have length 0 as two consecutive NULs indentify the end of the string list. But the suggested solution did not match the intent of the SMBIOS specification. Fixes: 00a871d34e2f ("smbios: empty strings in smbios_add_string()") Signed-off-by: Heinrich Schuchardt Reviewed-by: Ilias Apalodimas --- lib/smbios.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) diff --git a/lib/smbios.c b/lib/smbios.c index 0ae857855ec..6190c168f26 100644 --- a/lib/smbios.c +++ b/lib/smbios.c @@ -135,13 +135,16 @@ static const struct map_sysinfo *convert_sysinfo_to_dt(const char *node, const c * * @ctx: SMBIOS context * @str: string to add - * Return: string number in the string area (1 or more) + * Return: string number in the string area. 0 if str is NULL. */ static int smbios_add_string(struct smbios_ctx *ctx, const char *str) { int i = 1; char *p = ctx->eos; + if (!str) + return 0; + for (;;) { if (!*p) { ctx->last_str = p; @@ -217,7 +220,7 @@ static int smbios_add_prop_si(struct smbios_ctx *ctx, const char *prop, int ret; if (!dval || !*dval) - dval = "Unknown"; + dval = NULL; if (!prop) return smbios_add_string(ctx, dval); @@ -380,19 +383,19 @@ static int smbios_write_type1(ulong *current, int handle, memset(t, 0, sizeof(struct smbios_type1)); fill_smbios_header(t, SMBIOS_SYSTEM_INFORMATION, len, handle); smbios_set_eos(ctx, t->eos); - t->manufacturer = smbios_add_prop(ctx, "manufacturer", "Unknown"); - t->product_name = smbios_add_prop(ctx, "product", "Unknown"); + t->manufacturer = smbios_add_prop(ctx, "manufacturer", NULL); + t->product_name = smbios_add_prop(ctx, "product", NULL); t->version = smbios_add_prop_si(ctx, "version", SYSINFO_ID_SMBIOS_SYSTEM_VERSION, - "Unknown"); + NULL); if (serial_str) { t->serial_number = smbios_add_prop(ctx, NULL, serial_str); strncpy((char *)t->uuid, serial_str, sizeof(t->uuid)); } else { - t->serial_number = smbios_add_prop(ctx, "serial", "Unknown"); + t->serial_number = smbios_add_prop(ctx, "serial", NULL); } - t->sku_number = smbios_add_prop(ctx, "sku", "Unknown"); - t->family = smbios_add_prop(ctx, "family", "Unknown"); + t->sku_number = smbios_add_prop(ctx, "sku", NULL); + t->family = smbios_add_prop(ctx, "family", NULL); len = t->length + smbios_string_table_len(ctx); *current += len; @@ -411,12 +414,12 @@ static int smbios_write_type2(ulong *current, int handle, memset(t, 0, sizeof(struct smbios_type2)); fill_smbios_header(t, SMBIOS_BOARD_INFORMATION, len, handle); smbios_set_eos(ctx, t->eos); - t->manufacturer = smbios_add_prop(ctx, "manufacturer", "Unknown"); - t->product_name = smbios_add_prop(ctx, "product", "Unknown"); + t->manufacturer = smbios_add_prop(ctx, "manufacturer", NULL); + t->product_name = smbios_add_prop(ctx, "product", NULL); t->version = smbios_add_prop_si(ctx, "version", SYSINFO_ID_SMBIOS_BASEBOARD_VERSION, - "Unknown"); - t->asset_tag_number = smbios_add_prop(ctx, "asset-tag", "Unknown"); + NULL); + t->asset_tag_number = smbios_add_prop(ctx, "asset-tag", NULL); t->feature_flags = SMBIOS_BOARD_FEATURE_HOSTING; t->board_type = SMBIOS_BOARD_MOTHERBOARD; @@ -437,7 +440,7 @@ static int smbios_write_type3(ulong *current, int handle, memset(t, 0, sizeof(struct smbios_type3)); fill_smbios_header(t, SMBIOS_SYSTEM_ENCLOSURE, len, handle); smbios_set_eos(ctx, t->eos); - t->manufacturer = smbios_add_prop(ctx, "manufacturer", "Unknown"); + t->manufacturer = smbios_add_prop(ctx, "manufacturer", NULL); t->chassis_type = SMBIOS_ENCLOSURE_DESKTOP; t->bootup_state = SMBIOS_STATE_SAFE; t->power_supply_state = SMBIOS_STATE_SAFE; @@ -455,8 +458,8 @@ static void smbios_write_type4_dm(struct smbios_type4 *t, struct smbios_ctx *ctx) { u16 processor_family = SMBIOS_PROCESSOR_FAMILY_UNKNOWN; - const char *vendor = "Unknown"; - const char *name = "Unknown"; + const char *vendor = NULL; + const char *name = NULL; #ifdef CONFIG_CPU char processor_name[49]; -- cgit v1.2.3