From ae131f4970f0778f35ed06aeb15bde2fbc1d9619 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 13 Apr 2023 14:24:15 +0800 Subject: [PATCH] crypto: api - Add crypto_tfm_get Add a crypto_tfm_get interface to allow tfm objects to be shared. They can still be freed in the usual way. This should only be done with tfm objects with no keys. You must also not modify the tfm flags in any way once it becomes shared. Signed-off-by: Herbert Xu Reviewed-by: Simon Horman Signed-off-by: Herbert Xu --- crypto/api.c | 4 ++++ crypto/internal.h | 6 ++++++ include/linux/crypto.h | 1 + 3 files changed, 11 insertions(+) diff --git a/crypto/api.c b/crypto/api.c index e67cc63..f509d73 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -408,6 +408,7 @@ struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type, goto out_err; tfm->__crt_alg = alg; + refcount_set(&tfm->refcnt, 1); err = crypto_init_ops(tfm, type, mask); if (err) @@ -507,6 +508,7 @@ void *crypto_create_tfm_node(struct crypto_alg *alg, tfm = (struct crypto_tfm *)(mem + tfmsize); tfm->__crt_alg = alg; tfm->node = node; + refcount_set(&tfm->refcnt, 1); err = frontend->init_tfm(tfm); if (err) @@ -619,6 +621,8 @@ void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm) if (IS_ERR_OR_NULL(mem)) return; + if (!refcount_dec_and_test(&tfm->refcnt)) + return; alg = tfm->__crt_alg; if (!tfm->exit && alg->cra_exit) diff --git a/crypto/internal.h b/crypto/internal.h index f84dfe64..5eee009 100644 --- a/crypto/internal.h +++ b/crypto/internal.h @@ -10,6 +10,7 @@ #include #include +#include #include #include #include @@ -186,5 +187,10 @@ static inline int crypto_is_test_larval(struct crypto_larval *larval) return larval->alg.cra_driver_name[0]; } +static inline struct crypto_tfm *crypto_tfm_get(struct crypto_tfm *tfm) +{ + return refcount_inc_not_zero(&tfm->refcnt) ? tfm : ERR_PTR(-EOVERFLOW); +} + #endif /* _CRYPTO_INTERNAL_H */ diff --git a/include/linux/crypto.h b/include/linux/crypto.h index fdfa3e8..fa310ac 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -419,6 +419,7 @@ int crypto_has_alg(const char *name, u32 type, u32 mask); */ struct crypto_tfm { + refcount_t refcnt; u32 crt_flags; -- 2.7.4