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| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-03-02 12:23:45 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-05-11 16:35:32 +0200 |
| commit | efc0c21c9ea786d6f019d7df7b4e3932f3578d90 (patch) | |
| tree | 8d116630c8560d2b1398235a1d501082aa1b88b0 | |
| parent | d04a4c76f71dd5335f8e499b59617382d84e2b8d (diff) | |
| download | linux-efc0c21c9ea786d6f019d7df7b4e3932f3578d90.tar.bz2 | |
s390: convert debug_info.ref_count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | arch/s390/include/asm/debug.h | 3 | ||||
| -rw-r--r-- | arch/s390/kernel/debug.c | 8 |
2 files changed, 6 insertions, 5 deletions
diff --git a/arch/s390/include/asm/debug.h b/arch/s390/include/asm/debug.h index 0206c8052328..df7b54ea956d 100644 --- a/arch/s390/include/asm/debug.h +++ b/arch/s390/include/asm/debug.h @@ -10,6 +10,7 @@ #include <linux/spinlock.h> #include <linux/kernel.h> #include <linux/time.h> +#include <linux/refcount.h> #include <uapi/asm/debug.h> #define DEBUG_MAX_LEVEL 6 /* debug levels range from 0 to 6 */ @@ -31,7 +32,7 @@ struct debug_view; typedef struct debug_info { struct debug_info* next; struct debug_info* prev; - atomic_t ref_count; + refcount_t ref_count; spinlock_t lock; int level; int nr_areas; diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c index 530226b6cb19..86b3e74f569e 100644 --- a/arch/s390/kernel/debug.c +++ b/arch/s390/kernel/debug.c @@ -277,7 +277,7 @@ debug_info_alloc(const char *name, int pages_per_area, int nr_areas, memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS * sizeof(struct dentry*)); - atomic_set(&(rc->ref_count), 0); + refcount_set(&(rc->ref_count), 0); return rc; @@ -361,7 +361,7 @@ debug_info_create(const char *name, int pages_per_area, int nr_areas, debug_area_last = rc; rc->next = NULL; - debug_info_get(rc); + refcount_set(&rc->ref_count, 1); out: return rc; } @@ -416,7 +416,7 @@ static void debug_info_get(debug_info_t * db_info) { if (db_info) - atomic_inc(&db_info->ref_count); + refcount_inc(&db_info->ref_count); } /* @@ -431,7 +431,7 @@ debug_info_put(debug_info_t *db_info) if (!db_info) return; - if (atomic_dec_and_test(&db_info->ref_count)) { + if (refcount_dec_and_test(&db_info->ref_count)) { for (i = 0; i < DEBUG_MAX_VIEWS; i++) { if (!db_info->views[i]) continue; |