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| author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2023-11-22 18:29:33 +0100 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2023-11-23 15:45:54 +0100 |
| commit | b686114ba03d9d6a222ca21384ea8534f77a1af4 (patch) | |
| tree | 1bc7fa16b229b2d6a216e6aa77e2c2e8fd7f6631 /lib | |
| parent | c7710eefb960f08f8d812ce69b8aead786bb866b (diff) | |
| download | barebox-b686114ba03d9d6a222ca21384ea8534f77a1af4.tar.gz barebox-b686114ba03d9d6a222ca21384ea8534f77a1af4.tar.xz | |
include: add linux/refcount.h
For complex interactions, especially in communication protocols, it can
be beneficial to keep the reference counts used in the Linux drivers as
is to avoid resource leaks or use-after-frees.
Provide a simplified kref and refcount API to facilitate this.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20231122172951.376531-3-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/refcount.c | 34 |
2 files changed, 35 insertions, 0 deletions
diff --git a/lib/Makefile b/lib/Makefile index 791080b2d1..3e476a2c04 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -70,6 +70,7 @@ obj-$(CONFIG_BAREBOX_LOGO) += logo/ obj-y += reed_solomon/ obj-$(CONFIG_RATP) += ratp.o obj-y += list_sort.o +obj-y += refcount.o obj-y += int_sqrt.o obj-y += parseopt.o obj-y += clz_ctz.o diff --git a/lib/refcount.c b/lib/refcount.c new file mode 100644 index 0000000000..8c6f98b480 --- /dev/null +++ b/lib/refcount.c @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Out-of-line refcount functions. + */ + +#include <linux/refcount.h> +#include <linux/printk.h> + +#define REFCOUNT_WARN(str) WARN_ONCE(1, "refcount_t: " str ".\n") + +void refcount_warn_saturate(refcount_t *r, enum refcount_saturation_type t) +{ + refcount_set(r, REFCOUNT_SATURATED); + + switch (t) { + case REFCOUNT_ADD_NOT_ZERO_OVF: + REFCOUNT_WARN("saturated; leaking memory"); + break; + case REFCOUNT_ADD_OVF: + REFCOUNT_WARN("saturated; leaking memory"); + break; + case REFCOUNT_ADD_UAF: + REFCOUNT_WARN("addition on 0; use-after-free"); + break; + case REFCOUNT_SUB_UAF: + REFCOUNT_WARN("underflow; use-after-free"); + break; + case REFCOUNT_DEC_LEAK: + REFCOUNT_WARN("decrement hit 0; leaking memory"); + break; + default: + REFCOUNT_WARN("unknown saturation event!?"); + } +} |