[Crash-utility] [RFC] [PATCH 0/6] Add maple tree vma iteration support for crash

Patchset [1] introduces maple tree data structure for linux, and the modification on mm subsystem. The main impact on crash utility, is the modification on vm_area_struct. Patch [2][3] removed the rbtree and linked list iteration of vm_area_struct, making it impossible for crash to iterate vma in the traditional way. For example, we can observe the failing of crash cmd vm/fuser on kernel which has integrated with patchset [1]. This patchset deals with the issue by porting and adapting kernel's maple tree vma iteration code to crash utility. It has been tested on linux-next-next-20220914 [4]. Patch 1: the pure copy-and-paste work, extracting related kernel structures, functions, constants to crash. Patch 2: minimal code modification for crash adaption, kernel structures are kept for member resolving. Patch 3: modification on crash memory.c to use the maple vma iteration. The idea is to make patch 1-3 a POC work. Patch 4: Get rid of kernel structures by rewriting the structure member resolving code into the crash way, aka change "node->member" into "readmem(node) and OFFSET(member)" Patch 5: print the added variables of offset/size table Patch 6: Get rid of the compiling-time assgined arrays. Patch 4-6 will make the POC work formal for use. [1]: https://lore.kernel.org/all/20220906194824.2110408-1-Liam.Howlett@oracle.... [2]: https://github.com/oracle/linux-uek/commit/d19703645b80abe35dff1a88449d07... [3]: https://github.com/oracle/linux-uek/commit/91dee01f1ebb6b6587463b6ee6f7bb... [4]: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/snaps... Tao Liu (6): Port linux maple tree related files to crash Maple tree kernel code modification for step 1 Introduce maple tree vma iteration to memory.c Maple tree kernel code modification for step 2 Dump maple tree offset variables by help -o Remove mt_slots and mt_pivots array assignment Makefile | 12 +- defs.h | 19 ++ maple_tree.c | 824 +++++++++++++++++++++++++++++++++++++++++++++++ maple_tree.h | 109 +++++++ maple_tree_vma.h | 34 ++ memory.c | 315 ++++++++++-------- symbols.c | 34 ++ xarray.h | 70 ++++ 8 files changed, 1285 insertions(+), 132 deletions(-) create mode 100644 maple_tree.c create mode 100644 maple_tree.h create mode 100644 maple_tree_vma.h create mode 100644 xarray.h -- 2.33.1