diff options
| -rw-r--r-- | Documentation/admin-guide/kdump/kdump.rst | 4 | ||||
| -rw-r--r-- | kernel/crash_dump_dm_crypt.c | 52 |
2 files changed, 52 insertions, 4 deletions
diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst index b74d3bed8fff..e25edaa8e533 100644 --- a/Documentation/admin-guide/kdump/kdump.rst +++ b/Documentation/admin-guide/kdump/kdump.rst @@ -570,6 +570,10 @@ encrypted disk volume. User space can interact with cat /sys/kernel/config/crash_dm_crypt_keys/count 2 + # To support CPU/memory hot-plugging, re-use keys already saved to reserved + # memory + echo true > /sys/kernel/config/crash_dm_crypt_key/reuse + 2. Load the dump-capture kernel 3. After the dump-capture kerne get booted, restore the keys to user keyring diff --git a/kernel/crash_dump_dm_crypt.c b/kernel/crash_dump_dm_crypt.c index fb25f55f1512..5f4a62389150 100644 --- a/kernel/crash_dump_dm_crypt.c +++ b/kernel/crash_dump_dm_crypt.c @@ -28,6 +28,20 @@ static size_t get_keys_header_size(size_t total_keys) return struct_size(keys_header, keys, total_keys); } +static void get_keys_from_kdump_reserved_memory(void) +{ + struct keys_header *keys_header_loaded; + + arch_kexec_unprotect_crashkres(); + + keys_header_loaded = kmap_local_page(pfn_to_page( + kexec_crash_image->dm_crypt_keys_addr >> PAGE_SHIFT)); + + memcpy(keys_header, keys_header_loaded, get_keys_header_size(key_count)); + kunmap_local(keys_header_loaded); + arch_kexec_protect_crashkres(); +} + static int read_key_from_user_keying(struct dm_crypt_key *dm_key) { const struct user_key_payload *ukp; @@ -150,8 +164,36 @@ static ssize_t config_keys_count_show(struct config_item *item, char *page) CONFIGFS_ATTR_RO(config_keys_, count); +static bool is_dm_key_reused; + +static ssize_t config_keys_reuse_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d\n", is_dm_key_reused); +} + +static ssize_t config_keys_reuse_store(struct config_item *item, + const char *page, size_t count) +{ + if (!kexec_crash_image || !kexec_crash_image->dm_crypt_keys_addr) { + kexec_dprintk( + "dm-crypt keys haven't be saved to crash-reserved memory\n"); + return -EINVAL; + } + + if (kstrtobool(page, &is_dm_key_reused)) + return -EINVAL; + + if (is_dm_key_reused) + get_keys_from_kdump_reserved_memory(); + + return count; +} + +CONFIGFS_ATTR(config_keys_, reuse); + static struct configfs_attribute *config_keys_attrs[] = { &config_keys_attr_count, + &config_keys_attr_reuse, NULL, }; @@ -238,10 +280,12 @@ int crash_load_dm_crypt_keys(struct kimage *image) return -ENOENT; } - image->dm_crypt_keys_addr = 0; - r = build_keys_header(); - if (r) - return r; + if (!is_dm_key_reused) { + image->dm_crypt_keys_addr = 0; + r = build_keys_header(); + if (r) + return r; + } kbuf.buffer = keys_header; kbuf.bufsz = get_keys_header_size(key_count); |