From 70096a561d1e09120bae1f293f3632cedbfd5c68 Mon Sep 17 00:00:00 2001 From: Matt Mackall Date: Wed, 8 Oct 2008 14:51:57 -0500 Subject: [PATCH] SLOB: fix bogus ksize calculation fix This fixes the previous fix, which was completely wrong on closer inspection. This version has been manually tested with a user-space test harness and generates sane values. A nearly identical patch has been boot-tested. The problem arose from changing how kmalloc/kfree handled alignment padding without updating ksize to match. This brings it in sync. Signed-off-by: Matt Mackall Signed-off-by: Linus Torvalds --- mm/slob.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/slob.c b/mm/slob.c index 62b679dc660..cb675d12679 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -514,9 +514,11 @@ size_t ksize(const void *block) return 0; sp = (struct slob_page *)virt_to_page(block); - if (slob_page(sp)) - return (((slob_t *)block - 1)->units - 1) * SLOB_UNIT; - else + if (slob_page(sp)) { + int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); + unsigned int *m = (unsigned int *)(block - align); + return SLOB_UNITS(*m) * SLOB_UNIT; + } else return sp->page.private; }