From b25f97d0f8043903a64e3a203b79219cc69f2f77 Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Sat, 19 Apr 2025 06:36:53 +0800 Subject: [PATCH] mm/vmalloc.c: return explicit error value in alloc_vmap_area() In codes of alloc_vmap_area(), it returns the upper bound 'vend' to indicate if the allocation is successful or failed. That is not very clear. Here change to return explicit error values and check them to judge if allocation is successful. Link: https://lkml.kernel.org/r/20250418223653.243436-6-bhe@redhat.com Signed-off-by: Baoquan He Reviewed-by: Shivank Garg Reviewed-by: Uladzislau Rezki (Sony) Cc: Vishal Moola (Oracle) Signed-off-by: Andrew Morton --- mm/vmalloc.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index bfc2f2c45d893..701ea4ec8950e 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1716,7 +1716,7 @@ va_clip(struct rb_root *root, struct list_head *head, */ lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT); if (!lva) - return -1; + return -ENOMEM; } /* @@ -1730,7 +1730,7 @@ va_clip(struct rb_root *root, struct list_head *head, */ va->va_start = nva_start_addr + size; } else { - return -1; + return -EINVAL; } if (type != FL_FIT_TYPE) { @@ -1759,19 +1759,19 @@ va_alloc(struct vmap_area *va, /* Check the "vend" restriction. */ if (nva_start_addr + size > vend) - return vend; + return -ERANGE; /* Update the free vmap_area. */ ret = va_clip(root, head, va, nva_start_addr, size); if (WARN_ON_ONCE(ret)) - return vend; + return ret; return nva_start_addr; } /* * Returns a start address of the newly allocated area, if success. - * Otherwise a vend is returned that indicates failure. + * Otherwise an error value is returned that indicates failure. */ static __always_inline unsigned long __alloc_vmap_area(struct rb_root *root, struct list_head *head, @@ -1796,14 +1796,13 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head, va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size); if (unlikely(!va)) - return vend; + return -ENOENT; nva_start_addr = va_alloc(va, root, head, size, align, vstart, vend); - if (nva_start_addr == vend) - return vend; #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK - find_vmap_lowest_match_check(root, head, size, align); + if (!IS_ERR_VALUE(nva_start_addr)) + find_vmap_lowest_match_check(root, head, size, align); #endif return nva_start_addr; @@ -1933,7 +1932,7 @@ node_alloc(unsigned long size, unsigned long align, struct vmap_area *va; *vn_id = 0; - *addr = vend; + *addr = -EINVAL; /* * Fallback to a global heap if not vmalloc or there @@ -2013,20 +2012,20 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, } retry: - if (addr == vend) { + if (IS_ERR_VALUE(addr)) { preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node); addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list, size, align, vstart, vend); spin_unlock(&free_vmap_area_lock); } - trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend); + trace_alloc_vmap_area(addr, size, align, vstart, vend, IS_ERR_VALUE(addr)); /* - * If an allocation fails, the "vend" address is + * If an allocation fails, the error value is * returned. Therefore trigger the overflow path. */ - if (unlikely(addr == vend)) + if (IS_ERR_VALUE(addr)) goto overflow; va->va_start = addr; -- 2.39.5