diff options
| author | Kees Cook <keescook@chromium.org> | 2018-05-03 02:58:09 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2018-05-18 17:36:09 +0300 |
| commit | bbe21d7a979245902113e171fdb36b57812b3c3b (patch) | |
| tree | 065870886eef6ec945d0aa5f7e804c2017102969 /drivers/scsi/ufs | |
| parent | 66b7eaca548d716b86ae2417ec103a7f2f6c214c (diff) | |
| download | linux-bbe21d7a979245902113e171fdb36b57812b3c3b.tar.xz | |
scsi: ufs: ufshcd: Remove VLA usage
On the quest to remove all VLAs from the kernel[1] this moves buffers
off the stack. In the second instance, this collapses two separately
allocated buffers into a single buffer, since they are used
consecutively, which saves 256 bytes (QUERY_DESC_MAX_SIZE + 1) of stack
space.
[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/ufs')
| -rw-r--r-- | drivers/scsi/ufs/ufshcd.c | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index c5b1bf1cadcb..bbad34738bea 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5918,14 +5918,18 @@ static void ufshcd_init_icc_levels(struct ufs_hba *hba) { int ret; int buff_len = hba->desc_size.pwr_desc; - u8 desc_buf[hba->desc_size.pwr_desc]; + u8 *desc_buf; + + desc_buf = kmalloc(buff_len, GFP_KERNEL); + if (!desc_buf) + return; ret = ufshcd_read_power_desc(hba, desc_buf, buff_len); if (ret) { dev_err(hba->dev, "%s: Failed reading power descriptor.len = %d ret = %d", __func__, buff_len, ret); - return; + goto out; } hba->init_prefetch_data.icc_level = @@ -5943,6 +5947,8 @@ static void ufshcd_init_icc_levels(struct ufs_hba *hba) "%s: Failed configuring bActiveICCLevel = %d ret = %d", __func__, hba->init_prefetch_data.icc_level , ret); +out: + kfree(desc_buf); } /** @@ -6012,9 +6018,17 @@ static int ufs_get_device_desc(struct ufs_hba *hba, struct ufs_dev_desc *dev_desc) { int err; + size_t buff_len; u8 model_index; - u8 str_desc_buf[QUERY_DESC_MAX_SIZE + 1] = {0}; - u8 desc_buf[hba->desc_size.dev_desc]; + u8 *desc_buf; + + buff_len = max_t(size_t, hba->desc_size.dev_desc, + QUERY_DESC_MAX_SIZE + 1); + desc_buf = kmalloc(buff_len, GFP_KERNEL); + if (!desc_buf) { + err = -ENOMEM; + goto out; + } err = ufshcd_read_device_desc(hba, desc_buf, hba->desc_size.dev_desc); if (err) { @@ -6032,7 +6046,10 @@ static int ufs_get_device_desc(struct ufs_hba *hba, model_index = desc_buf[DEVICE_DESC_PARAM_PRDCT_NAME]; - err = ufshcd_read_string_desc(hba, model_index, str_desc_buf, + /* Zero-pad entire buffer for string termination. */ + memset(desc_buf, 0, buff_len); + + err = ufshcd_read_string_desc(hba, model_index, desc_buf, QUERY_DESC_MAX_SIZE, true/*ASCII*/); if (err) { dev_err(hba->dev, "%s: Failed reading Product Name. err = %d\n", @@ -6040,15 +6057,16 @@ static int ufs_get_device_desc(struct ufs_hba *hba, goto out; } - str_desc_buf[QUERY_DESC_MAX_SIZE] = '\0'; - strlcpy(dev_desc->model, (str_desc_buf + QUERY_DESC_HDR_SIZE), - min_t(u8, str_desc_buf[QUERY_DESC_LENGTH_OFFSET], + desc_buf[QUERY_DESC_MAX_SIZE] = '\0'; + strlcpy(dev_desc->model, (desc_buf + QUERY_DESC_HDR_SIZE), + min_t(u8, desc_buf[QUERY_DESC_LENGTH_OFFSET], MAX_MODEL_LEN)); /* Null terminate the model string */ dev_desc->model[MAX_MODEL_LEN] = '\0'; out: + kfree(desc_buf); return err; } |