Messages in this thread Patch in this message | | | From | Nicholas Mc Guire <> | Subject | [PATCH RFC] mm: vmalloc: do not allow kzalloc to fail | Date | Thu, 20 Dec 2018 21:23:57 +0100 |
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While this is in a very early stage of the system boot and if memory were exhausted the system has a more serious problem anyway - but still the kzalloc here seems unsafe. Looking at the history it was previously switched from alloc_bootmem() to kzalloc() using GFP_NOWAIT flag but there never seems to have been a check for NULL return. So if this is expected to never fail should it not be using | __GFP_NOFAIL here ? Or put differently - what is the rational for GFP_NOWAIT to be safe here ?
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Fixes 43ebdac42f16 ("vmalloc: use kzalloc() instead of alloc_bootmem()") ---
Problem was found by an experimental coccinelle script
Patch was only compile tested for x86_64_defconfig
Patch is against v4.20-rc7 (localversion-next next-20181220)
mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 871e41c..1c118d7 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1258,7 +1258,7 @@ void __init vmalloc_init(void) /* Import existing vmlist entries. */ for (tmp = vmlist; tmp; tmp = tmp->next) { - va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT); + va = kzalloc(sizeof(*va), GFP_NOWAIT | __GFP_NOFAIL); va->flags = VM_VM_AREA; va->va_start = (unsigned long)tmp->addr; va->va_end = va->va_start + tmp->size; -- 2.1.4
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