diff options
| author | Nathan Chancellor <nathan@kernel.org> | 2021-04-07 14:30:48 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-04-08 19:58:12 +0200 |
| commit | 2bc6262c6117dd18106d5aa50d53e945b5d99c51 (patch) | |
| tree | ed8f8c9417a2cc2daa999836af0d52ff825c4b2b /drivers/acpi/cppc_acpi.c | |
| parent | 8a02d99876362f35bc918097440445de18e3c47c (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/cppc_acpi.c')
| -rw-r--r-- | drivers/acpi/cppc_acpi.c | 14 |
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}; |