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 <mpm@selenic.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/slob.c b/mm/slob.c
index 62b679d..cb675d1 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -514,9 +514,11 @@
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;
}