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authorNathan Chancellor2021-04-07 14:30:48 -0700
committerRafael J. Wysocki2021-04-08 19:58:12 +0200
commit2bc6262c6117dd18106d5aa50d53e945b5d99c51 (patch)
treeed8f8c9417a2cc2daa999836af0d52ff825c4b2b /drivers/acpi
parent8a02d99876362f35bc918097440445de18e3c47c (diff)
ACPI: CPPC: Replace cppc_attr with kobj_attribute
All of the CPPC sysfs show functions are called via indirect call in kobj_attr_show(), where they should be of type ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, char *buf); because that is the type of the ->show() member in 'struct kobj_attribute' but they are actually of type ssize_t (*show)(struct kobject *kobj, struct attribute *attr, char *buf); because of the ->show() member in 'struct cppc_attr', resulting in a Control Flow Integrity violation [1]. $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/highest_perf 3400 $ dmesg | grep "CFI failure" [ 175.970559] CFI failure (target: show_highest_perf+0x0/0x8): As far as I can tell, the only difference between 'struct cppc_attr' and 'struct kobj_attribute' aside from the type of the attr parameter is the type of the count parameter in the ->store() member (ssize_t vs. size_t), which does not actually matter because all of these nodes are read-only. Eliminate 'struct cppc_attr' in favor of 'struct kobj_attribute' to fix the violation. [1]: https://lore.kernel.org/r/20210401233216.2540591-1-samitolvanen@google.com/ Fixes: 158c998ea44b ("ACPI / CPPC: add sysfs support to compute delivered performance") Link: https://github.com/ClangBuiltLinux/linux/issues/1343 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/cppc_acpi.c14
1 files changed, 3 insertions, 11 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index d20092815c39..2c2748041cef 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -118,23 +118,15 @@ static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr);
*/
#define NUM_RETRIES 500ULL
-struct cppc_attr {
- struct attribute attr;
- ssize_t (*show)(struct kobject *kobj,
- struct attribute *attr, char *buf);
- ssize_t (*store)(struct kobject *kobj,
- struct attribute *attr, const char *c, ssize_t count);
-};
-
#define define_one_cppc_ro(_name) \
-static struct cppc_attr _name = \
+static struct kobj_attribute _name = \
__ATTR(_name, 0444, show_##_name, NULL)
#define to_cpc_desc(a) container_of(a, struct cpc_desc, kobj)
#define show_cppc_data(access_fn, struct_name, member_name) \
static ssize_t show_##member_name(struct kobject *kobj, \
- struct attribute *attr, char *buf) \
+ struct kobj_attribute *attr, char *buf) \
{ \
struct cpc_desc *cpc_ptr = to_cpc_desc(kobj); \
struct struct_name st_name = {0}; \
@@ -160,7 +152,7 @@ show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf);
show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time);
static ssize_t show_feedback_ctrs(struct kobject *kobj,
- struct attribute *attr, char *buf)
+ struct kobj_attribute *attr, char *buf)
{
struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);
struct cppc_perf_fb_ctrs fb_ctrs = {0};