The patch titled Subject: mm/cma.c: make kmemleak aware of all CMA regions has been added to the -mm mm-unstable branch. Its filename is mm-cmac-make-kmemleak-aware-of-all-cma-regions.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
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@google.com Subject: mm/cma.c: make kmemleak aware of all CMA regions Date: Mon, 9 Jan 2023 14:16:22 -0800
Patch series "Fixes for kmemleak tracking with CMA regions".
When trying to boot a device with an ARM64 kernel with the following config options enabled:
CONFIG_DEBUG_PAGEALLOC=y CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT=y CONFIG_DEBUG_KMEMLEAK=y
a page-fault is encountered when kmemleak starts to scan the list of gray or allocated objects that it maintains. Upon closer inspection, it was observed that these page-faults always occurred when kmemleak attempted to scan a CMA region.
At the moment, kmemleak is made aware of CMA regions that are specified through the devicetree to be created at specific memory addresses or dynamically allocated within a range of addresses. However, if the CMA region is constrained to a certain range of addresses through the command line, the region is reserved through the memblock_reserve() function, but kmemleak_alloc_phys() is not invoked. Furthermore, kmemleak is never informed about CMA regions being freed to buddy at boot, which is problematic when CONFIG_DEBUG_PAGEALLOC is enabled, as all CMA regions are unmapped from the kernel's address space, and subsequently causes a page-fault when kmemleak attempts to scan any of them.
This series makes it so that kmemleak is aware of every CMA region before they are freed to the buddy allocator, so that at that time, kmemleak can be informed that each region is about to be freed, and thus it should not attempt to scan those regions.
This patch (of 2):
Currently, kmemleak tracks CMA regions that are specified through the devicetree. However, if the global CMA region is specified through the commandline, kmemleak will be unaware of the CMA region because kmemleak_alloc_phys() is not invoked after memblock_reserve(). Add the missing call to kmemleak_alloc_phys() so that all CMA regions are tracked by kmemleak before they are freed to the page allocator in cma_activate_area().
Link: https://lkml.kernel.org/r/20230109221624.592315-1-isaacmanjarres@google.com Link: https://lkml.kernel.org/r/20230109221624.592315-2-isaacmanjarres@google.com Signed-off-by: Isaac J. Manjarres isaacmanjarres@google.com Cc: stable@vger.kernel.org Cc: Catalin Marinas catalin.marinas@arm.com Cc: Saravana Kannan saravanak@google.com Cc: Suren Baghdasaryan surenb@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/cma.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/mm/cma.c~mm-cmac-make-kmemleak-aware-of-all-cma-regions +++ a/mm/cma.c @@ -318,6 +318,8 @@ int __init cma_declare_contiguous_nid(ph ret = -EBUSY; goto err; } + + kmemleak_alloc_phys(base, size, 0); } else { phys_addr_t addr = 0;
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Patches currently in -mm which might be from isaacmanjarres@google.com 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