[PATCH 1/2] scsi: myrb: fix -Wfortify-source

Nick Desaulniers
2023-08-28T22:26:53Z

truncate values at runtime via -Wfortify-source.

Fixes the warning:
drivers/scsi/myrb.c:1906:10: warning: 'snprintf' will always be
truncated; specified size is 32, but format string expands to at least
34 [-Wfortify-source]

In particular, the string literal "physical device - not rebuilding\n"
is indeed 34B by my count.

When we have a string literal that does not contain any format flags,
rather than use snprintf (sometimes with a size that's too small), let's
use sprintf.

This is pattern is cleaned up throughout the file.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://github.com/ClangBuiltLinux/linux/issues/1923
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
drivers/scsi/myrb.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/myrb.c b/drivers/scsi/myrb.c
index ca2e932dd9b7..c2bdff36a6f1 100644
--- a/drivers/scsi/myrb.c
+++ b/drivers/scsi/myrb.c
@@ -1767,7 +1767,7 @@ static ssize_t raid_state_show(struct device *dev,
int ret;

if (!sdev->hostdata)
- return snprintf(buf, 16, "Unknown\n");
+ return sprintf(buf, "Unknown\n");

if (sdev->channel == myrb_logical_channel(sdev->host)) {
struct myrb_ldev_info *ldev_info = sdev->hostdata;
@@ -1890,7 +1890,7 @@ static ssize_t raid_level_show(struct device *dev,
ldev_info->state);
return snprintf(buf, 32, "%s\n", name);
}
- return snprintf(buf, 32, "Physical Drive\n");
+ return sprintf(buf, "Physical Drive\n");
}
static DEVICE_ATTR_RO(raid_level);

@@ -1903,13 +1903,13 @@ static ssize_t rebuild_show(struct device *dev,
unsigned char status;

if (sdev->channel < myrb_logical_channel(sdev->host))
- return snprintf(buf, 32, "physical device - not rebuilding\n");
+ return sprintf(buf, "physical device - not rebuilding\n");

status = myrb_get_rbld_progress(cb, &rbld_buf);

if (rbld_buf.ldev_num != sdev->id ||
status != MYRB_STATUS_SUCCESS)
- return snprintf(buf, 32, "not rebuilding\n");
+ return sprintf(buf, "not rebuilding\n");

return snprintf(buf, 32, "rebuilding block %u of %u\n",
rbld_buf.ldev_size - rbld_buf.blocks_left,

--
2.42.0.rc2.253.gd59a3bf2b4-goog