diff options
| author | Phil Auld <pauld@redhat.com> | 2022-09-06 16:35:42 -0400 |
|---|---|---|
| committer | Yury Norov <yury.norov@gmail.com> | 2022-09-09 07:39:35 -0700 |
| commit | b9be19eef35587b15da0a5d887d6e04c0c6cefab (patch) | |
| tree | 6fd54f7acd21902792b24d0fc0fd72c9b2cb94ce /include/linux/cpumask.h | |
| parent | 7e18e42e4b280c85b76967a9106a13ca61c16179 (diff) | |
drivers/base: Fix unsigned comparison to -1 in CPUMAP_FILE_MAX_BYTES
As PAGE_SIZE is unsigned long, -1 > PAGE_SIZE when NR_CPUS <= 3.
This leads to very large file sizes:
topology$ ls -l
total 0
-r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 core_cpus
-r--r--r-- 1 root root 4096 Sep 5 11:59 core_cpus_list
-r--r--r-- 1 root root 4096 Sep 5 10:58 core_id
-r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 core_siblings
-r--r--r-- 1 root root 4096 Sep 5 11:59 core_siblings_list
-r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 die_cpus
-r--r--r-- 1 root root 4096 Sep 5 11:59 die_cpus_list
-r--r--r-- 1 root root 4096 Sep 5 11:59 die_id
-r--r--r-- 1 root root 18446744073709551615 Sep 5 11:59 package_cpus
-r--r--r-- 1 root root 4096 Sep 5 11:59 package_cpus_list
-r--r--r-- 1 root root 4096 Sep 5 10:58 physical_package_id
-r--r--r-- 1 root root 18446744073709551615 Sep 5 10:10 thread_siblings
-r--r--r-- 1 root root 4096 Sep 5 11:59 thread_siblings_list
Adjust the inequality to catch the case when NR_CPUS is configured
to a small value.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: stable@vger.kernel.org
Cc: feng xiangjun <fengxj325@gmail.com>
Fixes: 7ee951acd31a ("drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist")
Reported-by: feng xiangjun <fengxj325@gmail.com>
Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Diffstat (limited to 'include/linux/cpumask.h')
| -rw-r--r-- | include/linux/cpumask.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bd047864c7ac..e8ad12b5b9d2 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -1127,9 +1127,10 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask, * cover a worst-case of every other cpu being on one of two nodes for a * very large NR_CPUS. * - * Use PAGE_SIZE as a minimum for smaller configurations. + * Use PAGE_SIZE as a minimum for smaller configurations while avoiding + * unsigned comparison to -1. */ -#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \ +#define CPUMAP_FILE_MAX_BYTES (((NR_CPUS * 9)/32 > PAGE_SIZE) \ ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE) #define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE) |