From 47f3b1f243acfe755340753c5d467ba781618fa6 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Tue, 7 Jul 2020 20:51:38 +0200 Subject: [PATCH] env: Add option to only ever append environment Add configuration option which prevents the environment hash table to be ever cleared and reloaded with different content. This is useful in case the first environment loaded into the hash table contains e.g. sensitive content which must not be dropped or reloaded. Signed-off-by: Marek Vasut Reviewed-by: Tom Rini --- env/Kconfig | 9 +++++++++ env/env.c | 2 ++ lib/hashtable.c | 4 ++++ 3 files changed, 15 insertions(+) diff --git a/env/Kconfig b/env/Kconfig index dcc525d4ed..1cae1edf6a 100644 --- a/env/Kconfig +++ b/env/Kconfig @@ -614,6 +614,15 @@ config DELAY_ENVIRONMENT later by U-Boot code. With CONFIG_OF_CONTROL this is instead controlled by the value of /config/load-environment. +config ENV_APPEND + bool "Always append the environment with new data" + default n + help + If defined, the environment hash table is only ever appended with new + data, but the existing hash table can never be dropped and reloaded + with newly imported data. This may be used in combination with static + flags to e.g. to protect variables which must not be modified. + config ENV_ACCESS_IGNORE_FORCE bool "Block forced environment operations" default n diff --git a/env/env.c b/env/env.c index 2af2fae23c..42c7d8155e 100644 --- a/env/env.c +++ b/env/env.c @@ -201,7 +201,9 @@ int env_load(void) printf("OK\n"); gd->env_load_prio = prio; +#if !CONFIG_IS_ENABLED(ENV_APPEND) return 0; +#endif } else if (ret == -ENOMSG) { /* Handle "bad CRC" case */ if (best_prio == -1) diff --git a/lib/hashtable.c b/lib/hashtable.c index 7b6781bc35..ef834badc5 100644 --- a/lib/hashtable.c +++ b/lib/hashtable.c @@ -826,6 +826,10 @@ int himport_r(struct hsearch_data *htab, if (nvars) memcpy(localvars, vars, sizeof(vars[0]) * nvars); +#if CONFIG_IS_ENABLED(ENV_APPEND) + flag |= H_NOCLEAR; +#endif + if ((flag & H_NOCLEAR) == 0 && !nvars) { /* Destroy old hash table if one exists */ debug("Destroy Hash Table: %p table = %p\n", htab,