From 208d02fd5d165389aed0c2b60519cb6b0f5b89f9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jean-S=C3=A9bastien=20P=C3=A9dron?= Date: Fri, 11 Nov 2022 21:03:25 +0100 Subject: [PATCH] linuxkpi: Define `ZERO_OR_NULL_PTR()` in On Linux, the `kmalloc()` family of functions returns a special value if the size of the allocation is zero. This macro verifies if the pointer is NULL (the allocation failed) or the size is 0 (the allocation was not performed AFAIU). This special value can be passed to `kfree()`. On FreeBSD, our `malloc(9)` functions don't return a special value for 0-size allocations. Therefore we can simply compare the result against NULL. Reviewed by: manu Approved by: manu Differential Revision: https://reviews.freebsd.org/D37367 --- sys/compat/linuxkpi/common/include/linux/slab.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sys/compat/linuxkpi/common/include/linux/slab.h b/sys/compat/linuxkpi/common/include/linux/slab.h index 8f1cb433c36..915f33acf67 100644 --- a/sys/compat/linuxkpi/common/include/linux/slab.h +++ b/sys/compat/linuxkpi/common/include/linux/slab.h @@ -90,6 +90,8 @@ struct linux_kmem_cache; /* drm-kmod 5.4 compat */ #define kfree_async(ptr) kfree(ptr); +#define ZERO_OR_NULL_PTR(x) ((x) == NULL) + static inline gfp_t linux_check_m_flags(gfp_t flags) {