[tip: perf/core] x86/events/amd/iommu: Fix sysfs type mismatch

[tip-bot2 for Nathan Chancellor]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     de5bc7b425d4c27ae5faa00ea7eb6b9780b9a355
Gitweb:        https://git.kernel.org/tip/de5bc7b425d4c27ae5faa00ea7eb6b9780b9a355
Author:        Nathan Chancellor <nathan@xxxxxxxxxx>
AuthorDate:    Wed, 14 Apr 2021 17:11:11 -07:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 16 Apr 2021 18:58:52 +02:00

x86/events/amd/iommu: Fix sysfs type mismatch

dev_attr_show() calls _iommu_event_show() via an indirect call but
_iommu_event_show()'s 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_iommu_1/events/mem_dte_hit
csource=0x0a

$ dmesg | grep "CFI failure"
[ 3526.735140] CFI failure (target: _iommu_event_show...):

Change _iommu_event_show() and 'struct amd_iommu_event_desc' to
'struct device_attribute' so that there is no more CFI violation.

Fixes: 7be6296fdd75 ("perf/x86/amd: AMD IOMMU Performance Counter PERF uncore PMU implementation")
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20210415001112.3024673-1-nathan@xxxxxxxxxx
---
 arch/x86/events/amd/iommu.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c
index be50ef8..6a98a76 100644
--- a/arch/x86/events/amd/iommu.c
+++ b/arch/x86/events/amd/iommu.c
@@ -81,12 +81,12 @@ static struct attribute_group amd_iommu_events_group = {
 };
 
 struct amd_iommu_event_desc {
-	struct kobj_attribute attr;
+	struct device_attribute attr;
 	const char *event;
 };
 
-static ssize_t _iommu_event_show(struct kobject *kobj,
-				struct kobj_attribute *attr, char *buf)
+static ssize_t _iommu_event_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
 {
 	struct amd_iommu_event_desc *event =
 		container_of(attr, struct amd_iommu_event_desc, attr);