[PATCH] mlxbf-bootctl: use sysfs_emit_at() in secure_boot_fuse_state_show()

[PATCH] mlxbf-bootctl: use sysfs_emit_at() in secure_boot_fuse_state_show()

[David Thompson]

A warning is seen when running the latest kernel on a BlueField SOC:
[251.512704] ------------[ cut here ]------------
[251.512711] invalid sysfs_emit: buf:0000000003aa32ae
[251.512720] WARNING: CPU: 1 PID: 705264 at fs/sysfs/file.c:767 sysfs_emit+0xac/0xc8

The warning is triggered because the mlxbf-bootctl driver invokes
"sysfs_emit()" with a buffer pointer that is not aligned to the
start of the page. The driver should instead use "sysfs_emit_at()"
to support non-zero offsets into the destination buffer.

Fixes: 9886f575de5a ("platform/mellanox: mlxbf-bootctl: use sysfs_emit() instead of sprintf()")

Signed-off-by: David Thompson <davthompson@nvidia.com>
---
 drivers/platform/mellanox/mlxbf-bootctl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/mellanox/mlxbf-bootctl.c b/drivers/platform/mellanox/mlxbf-bootctl.c
index b95dcb8d483c..c18a5b96de5c 100644
--- a/drivers/platform/mellanox/mlxbf-bootctl.c
+++ b/drivers/platform/mellanox/mlxbf-bootctl.c
@@ -333,9 +333,9 @@ static ssize_t secure_boot_fuse_state_show(struct device *dev,
 			else
 				status = valid ? "Invalid" : "Free";
 		}
-		buf_len += sysfs_emit(buf + buf_len, "%d:%s ", key, status);
+		buf_len += sysfs_emit_at(buf, buf_len, "%d:%s ", key, status);
 	}
-	buf_len += sysfs_emit(buf + buf_len, "\n");
+	buf_len += sysfs_emit_at(buf, buf_len, "\n");
 
 	return buf_len;
 }
-- 
2.43.2

Re: [PATCH] mlxbf-bootctl: use sysfs_emit_at() in secure_boot_fuse_state_show()

[Ilpo Järvinen]

On Mon, 07 Apr 2025 13:25:58 +0000, David Thompson wrote:

> A warning is seen when running the latest kernel on a BlueField SOC:
> [251.512704] ------------[ cut here ]------------
> [251.512711] invalid sysfs_emit: buf:0000000003aa32ae
> [251.512720] WARNING: CPU: 1 PID: 705264 at fs/sysfs/file.c:767 sysfs_emit+0xac/0xc8
> 
> The warning is triggered because the mlxbf-bootctl driver invokes
> "sysfs_emit()" with a buffer pointer that is not aligned to the
> start of the page. The driver should instead use "sysfs_emit_at()"
> to support non-zero offsets into the destination buffer.
> 
> [...]


Thank you for your contribution, it has been applied to my local
review-ilpo-fixes branch. Note it will show up in the public
platform-drivers-x86/review-ilpo-fixes branch only once I've pushed my
local branch there, which might take a while.

The list of commits applied:
[1/1] mlxbf-bootctl: use sysfs_emit_at() in secure_boot_fuse_state_show()
      commit: b129005ddfc0e6daf04a6d3b928a9e474f9b3918

--
 i.