The patch titled
Subject: mm/cma.c: delete kmemleak objects when freeing CMA areas to buddy at boot
has been added to the -mm mm-unstable branch. Its filename is
mm-cmac-delete-kmemleak-objects-when-freeing-cma-areas-to-buddy-at-boot.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-cmac-delete-kmemleak-objects-when-freeing-cma-areas-to-buddy-at-boot.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Isaac J. Manjarres" <isaacmanjarres@xxxxxxxxxx>
Subject: mm/cma.c: delete kmemleak objects when freeing CMA areas to buddy at boot
Date: Mon, 9 Jan 2023 14:16:23 -0800
Since every CMA region is now tracked by kmemleak at the time
cma_activate_area() is invoked, and cma_activate_area() is called for each
CMA region, invoke kmemleak_free_part_phys() during cma_activate_area() to
inform kmemleak that the CMA region will be freed. Doing so also removes
the need to invoke kmemleak_ignore_phys() when the global CMA region is
being created, as the kmemleak object for it will be deleted.
This helps resolve a crash when kmemleak and CONFIG_DEBUG_PAGEALLOC are
both enabled, since CONFIG_DEBUG_PAGEALLOC causes the CMA region to be
unmapped from the kernel's address space when the pages are freed to
buddy. Without this patch, kmemleak will attempt to scan the CMA regions,
even though they are unmapped, which leads to a page-fault.
Link: https://lkml.kernel.org/r/20230109221624.592315-3-isaacmanjarres@xxxxxxxxxx
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx>
Cc: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx>
Cc: Saravana Kannan <saravanak@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/cma.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
--- a/mm/cma.c~mm-cmac-delete-kmemleak-objects-when-freeing-cma-areas-to-buddy-at-boot
+++ a/mm/cma.c
@@ -103,6 +103,13 @@ static void __init cma_activate_area(str
goto out_error;
/*
+ * The CMA region was marked as allocated by kmemleak when it was either
+ * dynamically allocated or statically reserved. In any case,
+ * inform kmemleak that the region is about to be freed to the page allocator.
+ */
+ kmemleak_free_part_phys(cma_get_base(cma), cma_get_size(cma));
+
+ /*
* alloc_contig_range() requires the pfn range specified to be in the
* same zone. Simplify by forcing the entire CMA resv range to be in the
* same zone.
@@ -361,11 +368,6 @@ int __init cma_declare_contiguous_nid(ph
}
}
- /*
- * kmemleak scans/reads tracked objects for pointers to other
- * objects but this address isn't mapped and accessible
- */
- kmemleak_ignore_phys(addr);
base = addr;
}
_
Patches currently in -mm which might be from isaacmanjarres@xxxxxxxxxx are
mm-cmac-make-kmemleak-aware-of-all-cma-regions.patch
mm-cmac-delete-kmemleak-objects-when-freeing-cma-areas-to-buddy-at-boot.patch
