On Fri, May 10, 2024 at 10:01 PM hailong.liu@oppo.com wrote:
From: "Hailong.Liu" hailong.liu@oppo.com
commit a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc") includes support for __GFP_NOFAIL, but it presents a conflict with commit dd544141b9eb ("vmalloc: back off when the current task is OOM-killed"). A possible scenario is as follows:
process-a __vmalloc_node_range(GFP_KERNEL | __GFP_NOFAIL) __vmalloc_area_node() vm_area_alloc_pages() --> oom-killer send SIGKILL to process-a if (fatal_signal_pending(current)) break; --> return NULL;
To fix this, do not check fatal_signal_pending() in vm_area_alloc_pages() if __GFP_NOFAIL set.
Fixes: 9376130c390a ("mm/vmalloc: add support for __GFP_NOFAIL") Cc: stable@vger.kernel.org Acked-by: Michal Hocko mhocko@suse.com Suggested-by: Barry Song 21cnbao@gmail.com Reported-by: Oven liyangouwen1@oppo.com Signed-off-by: Hailong.Liu hailong.liu@oppo.com
Reviewed-by: Barry Song baohua@kernel.org
mm/vmalloc.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 125427cbdb87..109272b8ee2e 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3492,7 +3492,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid, { unsigned int nr_allocated = 0; gfp_t alloc_gfp = gfp;
bool nofail = false;
bool nofail = gfp & __GFP_NOFAIL; struct page *page; int i;@@ -3549,12 +3549,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, * and compaction etc. */ alloc_gfp &= ~__GFP_NOFAIL;
nofail = true; } /* High-order pages or fallback path if "bulk" fails. */ while (nr_allocated < nr_pages) {if (fatal_signal_pending(current))
if (!nofail && fatal_signal_pending(current)) break; if (nid == NUMA_NO_NODE)