On Thu, Jun 26, 2025 at 05:51:30AM -0700, Chelsy Ratnawat wrote:
> Documentation/filesystems/sysfs.rst mentions that show() should only
> use sysfs_emit() or sysfs_emit_at() when formating the value to be
> returned to user space. So replace scnprintf() with sysfs_emit().
>
> Signed-off-by: Chelsy Ratnawat <chelsyratnawat2...@gmail.com>
> ---
> Changes in v5 :
> - Fix alignment and coding style problems
>
> drivers/char/tpm/tpm_ppi.c | 52 ++++++++++++++++++--------------------
> 1 file changed, 25 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
> index bc7b1b4501b3..d53fce1c9d6f 100644
> --- a/drivers/char/tpm/tpm_ppi.c
> +++ b/drivers/char/tpm/tpm_ppi.c
> @@ -52,7 +52,7 @@ static ssize_t tpm_show_ppi_version(struct device *dev,
> {
> struct tpm_chip *chip = to_tpm_chip(dev);
>
> - return scnprintf(buf, PAGE_SIZE, "%s\n", chip->ppi_version);
> + return sysfs_emit(buf, "%s\n", chip->ppi_version);
> }
>
> static ssize_t tpm_show_ppi_request(struct device *dev,
> @@ -87,12 +87,10 @@ static ssize_t tpm_show_ppi_request(struct device *dev,
> else {
> req = obj->package.elements[1].integer.value;
> if (tpm_ppi_req_has_parameter(req))
> - size = scnprintf(buf, PAGE_SIZE,
> - "%llu %llu\n", req,
> - obj->package.elements[2].integer.value);
> + size = sysfs_emit(buf, "%llu %llu\n", req,
> +
> obj->package.elements[2].integer.value);
> else
> - size = scnprintf(buf, PAGE_SIZE,
> - "%llu\n", req);
> + size = sysfs_emit(buf, "%llu\n", req);
> }
> } else if (obj->package.count == 2 &&
> obj->package.elements[0].type == ACPI_TYPE_INTEGER &&
> @@ -100,8 +98,8 @@ static ssize_t tpm_show_ppi_request(struct device *dev,
> if (obj->package.elements[0].integer.value)
> size = -EFAULT;
> else
> - size = scnprintf(buf, PAGE_SIZE, "%llu\n",
> - obj->package.elements[1].integer.value);
> + size = sysfs_emit(buf, "%llu\n",
> +
> obj->package.elements[1].integer.value);
> }
>
> ACPI_FREE(obj);
> @@ -211,10 +209,10 @@ static ssize_t tpm_show_ppi_transition_action(struct
> device *dev,
> }
>
> if (ret < ARRAY_SIZE(info) - 1)
> - status = scnprintf(buf, PAGE_SIZE, "%d: %s\n", ret, info[ret]);
> + status = sysfs_emit(buf, "%d: %s\n", ret, info[ret]);
> else
> - status = scnprintf(buf, PAGE_SIZE, "%d: %s\n", ret,
> - info[ARRAY_SIZE(info)-1]);
> + status = sysfs_emit(buf, "%d: %s\n", ret,
> + info[ARRAY_SIZE(info) - 1]);
> return status;
> }
>
> @@ -255,23 +253,23 @@ static ssize_t tpm_show_ppi_response(struct device *dev,
> res = ret_obj[2].integer.value;
> if (req) {
> if (res == 0)
> - status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
> - "0: Success");
> + status = sysfs_emit(buf, "%llu %s\n", req,
> + "0: Success");
> else if (res == 0xFFFFFFF0)
> - status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
> - "0xFFFFFFF0: User Abort");
> + status = sysfs_emit(buf, "%llu %s\n", req,
> + "0xFFFFFFF0: User Abort");
> else if (res == 0xFFFFFFF1)
> - status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
> - "0xFFFFFFF1: BIOS Failure");
> + status = sysfs_emit(buf, "%llu %s\n", req,
> + "0xFFFFFFF1: BIOS Failure");
> else if (res >= 1 && res <= 0x00000FFF)
> - status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
> - req, res, "Corresponding TPM error");
> + status = sysfs_emit(buf, "%llu %llu: %s\n",
> + req, res, "Corresponding TPM
> error");
> else
> - status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
> - req, res, "Error");
> + status = sysfs_emit(buf, "%llu %llu: %s\n",
> + req, res, "Error");
> } else {
> - status = scnprintf(buf, PAGE_SIZE, "%llu: %s\n",
> - req, "No Recent Request");
> + status = sysfs_emit(buf, "%llu: %s\n",
> + req, "No Recent Request");
> }
>
> cleanup:
> @@ -284,7 +282,7 @@ static ssize_t show_ppi_operations(acpi_handle
> dev_handle, char *buf, u32 start,
> {
> int i;
> u32 ret;
> - char *str = buf;
> + int len = 0;
> union acpi_object *obj, tmp;
> union acpi_object argv = ACPI_INIT_DSM_ARGV4(1, &tmp);
>
> @@ -314,11 +312,11 @@ static ssize_t show_ppi_operations(acpi_handle
> dev_handle, char *buf, u32 start,
> }
>
> if (ret > 0 && ret < ARRAY_SIZE(info))
> - str += scnprintf(str, PAGE_SIZE, "%d %d: %s\n",
> - i, ret, info[ret]);
> + len += sysfs_emit_at(buf, len, "%d %d: %s\n",
> + i, ret, info[ret]);
> }
>
> - return str - buf;
> + return len;
> }
>
> static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
> --
> 2.47.1
>
Looks good to me.
Reviewed-by: Jarkko Sakkinen <jar...@kernel.org>
BR, Jarkko
