Re: [PATCH v2 1/4] arch/x86/events/amd: Convert snprintf/sprintf to sysfs_emit

[Adrian Hunter]

On 26/01/24 08:13, Li Zhijian wrote:
> Per filesystems/sysfs.rst, show() should only use sysfs_emit()
> or sysfs_emit_at() when formatting the value to be returned to user space.
> 
> coccinelle complains that there are still a couple of functions that use
> snprintf(). Convert them to sysfs_emit().
> 
>> ./arch/x86/events/amd/core.c:1282:8-16: WARNING: please use sysfs_emit
> 
> This patch is generated by
> $ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/device_attr_show.cocci M=arch/x86/events/amd | sed -n '6,$p' | patch -p1
> 
> No functional change intended
> 
> CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> CC: Mark Rutland <mark.rutland@xxxxxxx>
> CC: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
> CC: Jiri Olsa <jolsa@xxxxxxxxxx>
> CC: Namhyung Kim <namhyung@xxxxxxxxxx>
> CC: Ian Rogers <irogers@xxxxxxxxxx>
> CC: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> CC: Borislav Petkov <bp@xxxxxxxxx>
> CC: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> CC: x86@xxxxxxxxxx
> CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>

Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
> V2: extract patch from the patch set[1] so that maintainer can accept it separately.
> [1] https://lore.kernel.org/lkml/20240116041129.3937800-1-lizhijian@xxxxxxxxxxx/
> ---
>  arch/x86/events/amd/core.c  | 2 +-
>  arch/x86/events/amd/iommu.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
> index 81f6d8275b6b..0d520592010c 100644
> --- a/arch/x86/events/amd/core.c
> +++ b/arch/x86/events/amd/core.c
> @@ -1279,7 +1279,7 @@ static ssize_t branches_show(struct device *cdev,
>  			      struct device_attribute *attr,
>  			      char *buf)
>  {
> -	return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu.lbr_nr);
> +	return sysfs_emit(buf, "%d\n", x86_pmu.lbr_nr);
>  }
>  
>  static DEVICE_ATTR_RO(branches);
> diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c
> index b15f7b950d2e..1126bda96d8f 100644
> --- a/arch/x86/events/amd/iommu.c
> +++ b/arch/x86/events/amd/iommu.c
> @@ -89,7 +89,7 @@ static ssize_t _iommu_event_show(struct device *dev,
>  {
>  	struct amd_iommu_event_desc *event =
>  		container_of(attr, struct amd_iommu_event_desc, attr);
> -	return sprintf(buf, "%s\n", event->event);
> +	return sysfs_emit(buf, "%s\n", event->event);
>  }
>  
>  #define AMD_IOMMU_EVENT_DESC(_name, _event)			\