Messages in this thread Patch in this message | | | Date | Fri, 17 Feb 2023 21:29:07 +0530 | From | Deepak R Varma <> | Subject | [PATCH 2/3] perf/x86/intel/pt: Use sysfs_emit() in show() callback function |
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Using sprintf/snprintf functions are error prone and suggested to be replaced by scnprintf/vscnrptintf as outlined in this [1] LWN article.
A more recent recommendation is to use sysfs_emit() or sysfs_emit_at() as per Documentation/filesystems/sysfs.rst in show() callback function when formatting values to be returned to user-space. These helper functions are PAGE_SIZE aware and wrap a safer call to vscnprintf().
[1] https://lwn.net/Articles/69419/
Issue identified using the coccinelle device_attr_show.cocci script.
Signed-off-by: Deepak R Varma <drv@mailo.com> --- arch/x86/events/intel/pt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 42a55794004a..d9e6d771b458 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -96,7 +96,7 @@ static ssize_t pt_cap_show(struct device *cdev, container_of(attr, struct dev_ext_attribute, attr); enum pt_capabilities cap = (long)ea->var; - return snprintf(buf, PAGE_SIZE, "%x\n", intel_pt_validate_hw_cap(cap)); + return sysfs_emit(buf, "%x\n", intel_pt_validate_hw_cap(cap)); } static struct attribute_group pt_cap_group __ro_after_init = { -- 2.34.1
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