diff options
| -rw-r--r-- | core/nvram-format.c | 23 | ||||
| -rw-r--r-- | core/nvram.c | 45 | ||||
| -rw-r--r-- | core/test/run-nvram-format.c | 5 | ||||
| -rw-r--r-- | include/nvram.h | 1 |
4 files changed, 57 insertions, 17 deletions
diff --git a/core/nvram-format.c b/core/nvram-format.c index 227147e..b98aee1 100644 --- a/core/nvram-format.c +++ b/core/nvram-format.c @@ -208,12 +208,27 @@ static const char *find_next_key(const char *start, const char *end) */ const char *nvram_query(const char *key) { - const char *part_end = (const char *) skiboot_part_hdr + - skiboot_part_hdr->len * 16 - 1; - const char *start = (const char *) skiboot_part_hdr + - sizeof(*skiboot_part_hdr); + const char *part_end, *start; int key_len = strlen(key); + /* + * The running OS can modify the NVRAM as it pleases so we need to be + * a little paranoid and check that it's ok before we try parse it. + * + * NB: nvram_validate() can update skiboot_part_hdr + */ + if (!nvram_validate()) { + prerror("NVRAM: Look up for '%s' failed due to bad format!\n", + key); + return NULL; + } + + part_end = (const char *) skiboot_part_hdr + + skiboot_part_hdr->len * 16 - 1; + + start = (const char *) skiboot_part_hdr + + sizeof(*skiboot_part_hdr); + if (!key_len) { prlog(PR_WARNING, "NVRAM: search key is empty!\n"); return NULL; diff --git a/core/nvram.c b/core/nvram.c index 3ae0f12..2140706 100644 --- a/core/nvram.c +++ b/core/nvram.c @@ -24,7 +24,9 @@ static void *nvram_image; static uint32_t nvram_size; -static bool nvram_ready; + +static bool nvram_ready; /* has the nvram been loaded? */ +static bool nvram_valid; /* is the nvram format ok? */ static int64_t opal_read_nvram(uint64_t buffer, uint64_t size, uint64_t offset) { @@ -55,21 +57,37 @@ static int64_t opal_write_nvram(uint64_t buffer, uint64_t size, uint64_t offset) memcpy(nvram_image + offset, (void *)buffer, size); if (platform.nvram_write) platform.nvram_write(offset, nvram_image + offset, size); + + /* The host OS has written to the NVRAM so we can't be sure that it's + * well formatted. + */ + nvram_valid = false; + return OPAL_SUCCESS; } opal_call(OPAL_WRITE_NVRAM, opal_write_nvram, 3); -static void nvram_validate(void) +bool nvram_validate(void) +{ + if (!nvram_valid) + nvram_valid = !nvram_check(nvram_image, nvram_size); + + return nvram_valid; +} + +static void nvram_reformat(void) { - /* Check and maybe format nvram */ - if (nvram_check(nvram_image, nvram_size)) { - if (nvram_format(nvram_image, nvram_size)) - prerror("NVRAM: Failed to format NVRAM!\n"); - - /* Write the whole thing back */ - if (platform.nvram_write) - platform.nvram_write(0, nvram_image, nvram_size); + if (nvram_format(nvram_image, nvram_size)) { + prerror("NVRAM: Failed to format NVRAM!\n"); + nvram_valid = false; + return; } + + /* Write the whole thing back */ + if (platform.nvram_write) + platform.nvram_write(0, nvram_image, nvram_size); + + nvram_valid = true; } void nvram_reinit(void) @@ -77,8 +95,8 @@ void nvram_reinit(void) /* It's possible we failed to load nvram at boot. */ if (!nvram_ready) nvram_init(); - else - nvram_validate(); + else if (!nvram_validate()) + nvram_reformat(); } void nvram_read_complete(bool success) @@ -92,7 +110,8 @@ void nvram_read_complete(bool success) return; } - nvram_validate(); + if (!nvram_validate()) + nvram_reformat(); /* Add nvram node */ np = dt_new(opal_node, "nvram"); diff --git a/core/test/run-nvram-format.c b/core/test/run-nvram-format.c index 4bf3ae0..4ca2cde 100644 --- a/core/test/run-nvram-format.c +++ b/core/test/run-nvram-format.c @@ -18,6 +18,11 @@ #include "../nvram-format.c" +bool nvram_validate(void) +{ + return true; +} + static char *nvram_reset(void *nvram_image, int size) { struct chrp_nvram_hdr *h = nvram_image; diff --git a/include/nvram.h b/include/nvram.h index 19f8eff..d87561d 100644 --- a/include/nvram.h +++ b/include/nvram.h @@ -20,6 +20,7 @@ int nvram_format(void *nvram_image, uint32_t nvram_size); int nvram_check(void *nvram_image, uint32_t nvram_size); void nvram_reinit(void); +bool nvram_validate(void); const char *nvram_query(const char *name); |