From f7a35a3c36d1e36059c5654737d9bee3454f01a3 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 15 May 2025 14:42:15 -0700 Subject: [PATCH] mm: vmalloc: actually use the in-place vrealloc region Patch series "mm: vmalloc: Actually use the in-place vrealloc region". This fixes a performance regression[1] with vrealloc()[1]. The refactoring to not build a new vmalloc region only actually worked when shrinking. Actually return the resized area when it grows. Ugh. Link: https://lkml.kernel.org/r/20250515214217.619685-1-kees@kernel.org Fixes: a0309faf1cb0 ("mm: vmalloc: support more granular vrealloc() sizing") Signed-off-by: Kees Cook Reported-by: Shung-Hsi Yu Closes: https://lore.kernel.org/all/20250515-bpf-verifier-slowdown-vwo2meju4cgp2su5ckj@6gi6ssxbnfqg [1] Tested-by: Eduard Zingerman Tested-by: Pawan Gupta Tested-by: Shung-Hsi Yu Reviewed-by: "Uladzislau Rezki (Sony)" Reviewed-by: Danilo Krummrich Cc: "Erhard F." Cc: Signed-off-by: Andrew Morton --- mm/vmalloc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 2d7511654831..74bd00fd734d 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -4111,6 +4111,7 @@ void *vrealloc_noprof(const void *p, size_t size, gfp_t flags) if (want_init_on_alloc(flags)) memset((void *)p + old_size, 0, size - old_size); vm->requested_size = size; + return (void *)p; } /* TODO: Grow the vm_area, i.e. allocate and map additional pages. */