[PATCH 5.11 381/601] perf/amd/uncore: Fix sysfs type mismatch

Greg Kroah-Hartman
2021-05-12T17:41:45Z

From: Nathan Chancellor <nathan@kernel.org>

[ Upstream commit 5deac80d4571dffb51f452f0027979d72259a1b9 ]

dev_attr_show() calls the __uncore_*_show() functions via an indirect
call but their type does not currently match the type of the show()
member in 'struct device_attribute', resulting in a Control Flow
Integrity violation.

$ cat /sys/devices/amd_l3/format/umask
config:8-15

$ dmesg | grep "CFI failure"
[ 1258.174653] CFI failure (target: __uncore_umask_show...):

Update the type in the DEFINE_UNCORE_FORMAT_ATTR macro to match
'struct device_attribute' so that there is no more CFI violation.

Fixes: 06f2c24584f3 ("perf/amd/uncore: Prepare to scale for more attributes that vary per family")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210415001112.3024673-2-nathan@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/events/amd/uncore.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index 7f014d450bc2..582c0ffb5e98 100644
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -275,14 +275,14 @@ static struct attribute_group amd_uncore_attr_group = {
};

#define DEFINE_UNCORE_FORMAT_ATTR(_var, _name, _format) \
-static ssize_t __uncore_##_var##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, \
+static ssize_t __uncore_##_var##_show(struct device *dev, \
+ struct device_attribute *attr, \
char *page) \
{ \
BUILD_BUG_ON(sizeof(_format) >= PAGE_SIZE); \
return sprintf(page, _format "\n"); \
} \
-static struct kobj_attribute format_attr_##_var = \
+static struct device_attribute format_attr_##_var = \
__ATTR(_name, 0444, __uncore_##_var##_show, NULL)

DEFINE_UNCORE_FORMAT_ATTR(event12, event, "config:0-7,32-35");
--
2.30.2