[PATCH 01/10] dm-ima: remove dm_ima_reset_data()

Benjamin Marzinski
2026-04-14T00:22:52Z

There's no point in saving the string length of DM_IMA_VERSION_STR. It's
a constant, so the compiler will precompute it. dm_create() will already
zero out the rest of dm->ima.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
drivers/md/dm-ima.c | 32 ++++++++++++--------------------
drivers/md/dm-ima.h | 3 ---
drivers/md/dm.c | 2 --
3 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/drivers/md/dm-ima.c b/drivers/md/dm-ima.c
index 9495ca035056..a639bb0fe6c3 100644
--- a/drivers/md/dm-ima.c
+++ b/drivers/md/dm-ima.c
@@ -159,15 +159,6 @@ static int dm_ima_alloc_and_copy_capacity_str(struct mapped_device *md, char **c
capacity);
}

-/*
- * Initialize/reset the dm ima related data structure variables.
- */
-void dm_ima_reset_data(struct mapped_device *md)
-{
- memset(&(md->ima), 0, sizeof(md->ima));
- md->ima.dm_version_str_len = strlen(DM_IMA_VERSION_STR);
-}
-
/*
* Build up the IMA data for each target, and finally measure.
*/
@@ -204,8 +195,8 @@ void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_fl

sha256_init(&hash_ctx);

- memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
- l += table->md->ima.dm_version_str_len;
+ memcpy(ima_buf + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+ l += strlen(DM_IMA_VERSION_STR);

device_data_buf_len = strlen(device_data_buf);
memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
@@ -260,8 +251,8 @@ void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_fl
* prefix, so that multiple records from the same "dm_table_load" for
* a given device can be linked together.
*/
- memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
- l += table->md->ima.dm_version_str_len;
+ memcpy(ima_buf + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+ l += strlen(DM_IMA_VERSION_STR);

memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
l += device_data_buf_len;
@@ -349,8 +340,8 @@ void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap)
if (capacity_len < 0)
goto error;

- memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
- l += md->ima.dm_version_str_len;
+ memcpy(device_table_data + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+ l += strlen(DM_IMA_VERSION_STR);

if (swap) {
if (md->ima.active_table.hash != md->ima.inactive_table.hash)
@@ -460,8 +451,8 @@ void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all)
goto exit;
}

- memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
- l += md->ima.dm_version_str_len;
+ memcpy(device_table_data + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+ l += strlen(DM_IMA_VERSION_STR);

if (md->ima.active_table.device_metadata) {
memcpy(device_table_data + l, device_active_str, device_active_len);
@@ -551,7 +542,8 @@ void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all)
if (md->ima.active_table.hash != md->ima.inactive_table.hash)
kfree(md->ima.inactive_table.hash);

- dm_ima_reset_data(md);
+ memset(&md->ima.active_table, 0, sizeof(md->ima.active_table));
+ memset(&md->ima.inactive_table, 0, sizeof(md->ima.inactive_table));

kfree(dev_name);
kfree(dev_uuid);
@@ -578,8 +570,8 @@ void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map)
if (capacity_len < 0)
goto error1;

- memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
- l += md->ima.dm_version_str_len;
+ memcpy(device_table_data + l, DM_IMA_VERSION_STR, strlen(DM_IMA_VERSION_STR));
+ l += strlen(DM_IMA_VERSION_STR);

if (md->ima.inactive_table.device_metadata_len &&
md->ima.inactive_table.hash_len) {
diff --git a/drivers/md/dm-ima.h b/drivers/md/dm-ima.h
index a403deca6093..b0b166aa2283 100644
--- a/drivers/md/dm-ima.h
+++ b/drivers/md/dm-ima.h
@@ -52,10 +52,8 @@ struct dm_ima_device_table_metadata {
struct dm_ima_measurements {
struct dm_ima_device_table_metadata active_table;
struct dm_ima_device_table_metadata inactive_table;
- unsigned int dm_version_str_len;
};

-void dm_ima_reset_data(struct mapped_device *md);
void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags);
void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap);
void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all);
@@ -64,7 +62,6 @@ void dm_ima_measure_on_device_rename(struct mapped_device *md);

#else

-static inline void dm_ima_reset_data(struct mapped_device *md) {}
static inline void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags) {}
static inline void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap) {}
static inline void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all) {}
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index e178fe19973e..8b60c9804f5b 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2546,8 +2546,6 @@ int dm_create(int minor, struct mapped_device **result)
if (!md)
return -ENXIO;

- dm_ima_reset_data(md);
-
*result = md;
return 0;
}
--
2.53.0