lkml.org 
[lkml]   [2023]   [Feb]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 2/3] perf/x86/intel/pt: Use sysfs_emit() in show() callback function
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


\
 
 \ /
  Last update: 2023-03-27 00:27    [W:0.095 / U:0.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site