Update the malloc() with more info about the debugging features:
- CONFIG_MALLOC_DEBUG and CONFIG_MCHECK_HEAP_PROTECTION Kconfig options
- The malloc command with info and dump subcommands
- Caller backtrace display when mcheck is enabled
Series-to: concept
Series-cc: heinrich
Series-version: 2
Cover-letter:
malloc: Add heap debugging commands and mcheck caller tracking
This series adds improved heap-debugging capabilities.
As part of this, the recently added backtrace feature is reworked to
avoid itself using malloc(), which makes it difficult for malloc() to
use.
A new 'malloc' command with 'info' and 'dump' subcommands allows
inspecting the heap state at runtime.
The mcheck heap-protection feature is integrated into Kconfig and can be
used to to track caller information for each allocation, showing the
function name and line number.
The caller info can be seen with 'malloc dump', including for freed
chunks where possible.
The 'malloc info' command shows a few more heap statistics:
=> malloc info
total bytes = 96 MiB
in use bytes = 700.9 KiB
malloc count = 1234
free count = 567
realloc count = 89
The 'malloc dump' command walks the heap showing each chunk:
=> malloc dump
Heap dump: 19a0e000 - 1fa10000
Address Size Status
----------------------------------
19a0e000 10 (chunk header)
19a0e010 a0 log_init:453 <-board_init_r:774 <-sandbox_flow:
19a0e0b0 20070 membuf_new:420 <-console_record_init:880 <-boar
19a2e120 170 membuf_new:420 <-console_record_init:886 <-boar
19a2e290 150 unflatten_device_tree:299 <-of_live_build:328 <
19a2e3e0 a0 uclass_get:157 <-device_bind_common:59 <-device
...
19a4b080 70 free done_word:2489 <-parse_stream_outer:3190 <-pars
...
This is useful for debugging memory leaks, understanding allocation
patterns, and tracking down heap corruption issues.
Some additional patches are included to make all this work:
- format_size() for human-readable size formatting
- ut_asserteq_regex() for flexible test assertions
- backtrace_str() for condensed backtrace output
Finally, this series includes a few patches for some of the more obvious
memory leaks (scmi and some test drivers), plus a reduction in truetype
memory allocations and a fix for a watchdog crash with 'ut dm'.
END
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
Add doc/develop/malloc.rst documenting U-Boot's dynamic memory
allocation implementation:
- Overview of pre/post-relocation malloc phases
- dlmalloc 2.8.6 version and features
- Data structure sizes (~500 bytes vs 1032 bytes in 2.6.6)
- Configuration options for code-size optimization
- Debugging features (mcheck, valgrind, malloc testing)
- API reference
Also add an introductory comment to dlmalloc.c summarising the
U-Boot configuration.
Series-to: concept
Series-cc: heinrich
Cover-letter:
malloc: Import dlmalloc 2.8.6
This series imports dlmalloc 2.8.6 from Doug Lea, replacing the old
version 2.6.6 that U-Boot has been using since 2002.
The new version provides:
- Better memory efficiency with improved binning algorithms
- More robust overflow checking via MAX_REQUEST
- Somewhat cleaner codebase
All U-Boot-specific modifications from the historical commits have been
ported to the new implementation, including:
- Pre-relocation malloc via malloc_simple
- Valgrind annotations
- Malloc testing infrastructure
- mcheck heap protection support
- Sandbox USE_DL_PREFIX support
The approach here is to leave the upstream code unchanged, so much as
possible, clearly marking U-Boot-specific changes with an #ifdef
Unfortunately the code size is not great out-of-the-box, so the final
part of the series includes some options to remove in-place realloc(),
provide a simplified init, remove the tree stucture for large blocks
and a few other things.
With these adjustments the new version is about 1K less code on Thumb2
(firefly-rk3288).
The new free() algorithm is more sophisticated but also larger. If
needed we might be able to shrink by a few hundred bytes. Of course SPL
doesn't normally use free() so the benefit might be minimal.
Another point worth mentioning is that the pre-inited av_[] array has
been replaced replaced with a BSS _sm_ struct which reduces the image
size by about 1.5K. One patch adjusts some imx8mp boards to deal with
the larger BSS.
Some code-size stats:
$ buildman -b mala imx8mp_venice firefly-rk3288 firefly-rk3399 -sS --step 0
Summary of 2 commits for 3 boards (3 threads, 11 jobs per thread)
01: backtrace: Strip the source tree prefix from filenames
aarch64: w+ imx8mp_venice firefly-rk3399
40: doc: Add malloc documentation
aarch64: (for 2/2 boards) all -3904.0 bss +864.0 data -2076.0
spl/u-boot-spl:all -654.0 spl/u-boot-spl:bss +316.0
spl/u-boot-spl:data -1034.0 spl/u-boot-spl:text +64.0 text -2692.0
arm: (for 1/1 boards) all -1436.0 data -1040.0 text -396.0
For the new malloc.h I have avoided including string.h so have added
that to various places that need it.
The existing common/dlmalloc.src file is left alone.
In order to bring this in without losing functionality, I went through
the patches applied to the original implementation over time. Where
these commits were added, they are added as a cherry-pick, with the
original commit hash.
Here is a list of what was done with each U-Boot commit on top of the
new common/dlmalloc.c and include/malloc.h:
1. 217c9dad82 2002-10-25 Initial revision
- Ignored
2. 5b1d713721 2002-11-03 Initial revision
- Ignored
3. 8bde7f776c 2003-06-27 * Code cleanup:
- Ignored as we don't really want to change the style
4. d87080b721 2006-03-31 GCC-4.x fixes: clean up global data pointer initialization for all boards.
- Global data is not needed at this point
5. 81673e9ae1 2008-05-13 Make sure common.h is the first include.
- common.h has been removed
6. f2302d4430 2008-08-06 Fix merge problems
- no merge problems to fix with the new code
7. 60a3f404ac 2009-06-13 malloc.h: protect it against multiple include
- Already covered: new malloc.h has MALLOC_280_H include guards
8. 5e93bd1c9a 2009-08-21 Consolidate arch-specific sbrk() implementations
- Already covered: sbrk() and mem_malloc_init() in separate commit
9. d4e8ada0f6 2009-08-21 Consolidate arch-specific mem_malloc_init() implementations
- Already covered: mem_malloc_init() in separate commit
10. 521af04d85 2009-09-21 Conditionally perform common relocation fixups
- Not needed: Manual relocation removed in 4babaa0c28
11. b4feeb4e8a 2009-11-24 i386: Fix malloc initialization
- Already covered: mem_malloc_init() is common, no arch-specific guards
12. 2740544881 2010-01-15 malloc: return NULL if not initialized yet
- Done: Add check in dlmalloc() to return NULL if not initialized
13. ae30b8c200 2010-04-06 malloc: sbrk() should return MORECORE_FAILURE instead of NULL on failure
- Already covered: sbrk() returns MFAIL on failure
14. ea882baf9c 2010-06-20 New implementation for internal handling of environment variables.
- Not needed: Just changes #if 0 to #ifdef DEBUG for old stats code
15. 1ba91ba233 2010-10-14 dlmalloc.c: Fix gcc alias warning
- Not needed: New dlmalloc has no strict-aliasing warnings
16. 2e5167ccad 2010-10-28 Replace CONFIG_RELOC_FIXUP_WORKS by CONFIG_NEEDS_MANUAL_RELOC
- Not needed: Manual relocation removed in 4babaa0c28
17. 6163f5b4c8 2010-11-15 malloc: Fix issue with calloc memory possibly being non-zero
- Already covered: sbrk() clears memory on negative increment
18. 21726a7afc 2011-06-29 Add assert() for debug assertions
- Not needed: New dlmalloc uses U-Boot's global assert()
19. ea95cb7331 2011-09-10 utx8245: fix build breakage due to assert()
- Not needed: New dlmalloc has different debug check functions
20. 213adf6dff 2012-03-29 Malloc: Fix -Wundef warnings
- Not needed: New malloc.h doesn't have these #if issues
21. 93691842e8 2012-09-04 Fix strict-aliasing warning in dlmalloc
- Not needed: New dlmalloc has no malloc_bin_reloc()
22. 00d0d2ad4e 2012-06-03 malloc: remove extern declarations of malloc_bin_reloc() in board.c files
- Not needed: New dlmalloc has no malloc_bin_reloc()
23. 199adb601f 2012-10-29 common/misc: sparse fixes
- Not needed: New dlmalloc uses proper NULL
24. 7b395232da 2013-01-21 malloc: make malloc_bin_reloc static
- Not needed: New dlmalloc has no malloc_bin_reloc()
25. 472d546054 2013-04-01 Consolidate bool type
- Not needed: Just a comment change (True -> true)
26. d93041a4ca 2014-07-10 Remove form-feeds from dlmalloc.c
- Not needed: New dlmalloc doesn't have form-feeds
27. d59476b644 2014-07-10 Add a simple malloc() implementation for pre-relocation
- Done (updated): Redirect to malloc_simple before GD_FLG_FULL_MALLOC_INIT
28. 6d7601e744 2014-07-10 sandbox: Always enable malloc debug
- Done (updated): Combined with #64, use 'DEBUG 1' for new dlmalloc
29. 854d2b9753 2014-10-29 dlmalloc: ensure gd is set for early alloc
- Not needed: Reverted by #38
30. 868de51dde 2014-08-26 malloc: Output region when debugging
- Already covered: debug() message in mem_malloc_init()
31. c9356be307 2014-11-10 dm: Split the simple malloc() implementation into its own file
- Already covered: Redirect to malloc_simple.c via GD_FLG_FULL_MALLOC_INIT
32. 0aa8a4ad99 2015-03-04 dlmalloc: do memset in malloc init as new default config
- Already covered: SYS_MALLOC_CLEAR_ON_INIT at line 6396
33. fb5cf7f16b 2015-02-27 Move initf_malloc() to a common place
- Already covered: initf_malloc() at line 6357
34. 1eb0c03c21 2015-09-13 malloc_simple: Add Kconfig option for using only malloc_simple in the SPL
- Not needed: Changes to Kconfig/malloc_simple.c, not dlmalloc.c
35. 4f144a4164 2016-01-25 malloc: work around some memalign fragmentation issues
- Done (updated): Ported to internal_memalign() at line 4955
36. ee05fedc6c 2016-02-04 malloc: solve dead code issue in memalign()
- Not needed: New dlmalloc 2.8.6 has rewritten internal_memalign()
37. 2f0bcd4de1 2016-03-05 malloc: use hidden visibility
- Done (updated): Use DLMALLOC_EXPORT at line 546
38. deff6fb3a7 2016-03-05 malloc: remove !gd handling
- Not needed: Reverts #29, we don't add gd check
39. 4eece2602b 2016-04-21 common/dlmalloc.c: Delete content that was moved to malloc.h
- Not needed: New dlmalloc doesn't have #if 0 code
40. 034eda867f 2016-04-25 malloc: improve memalign fragmentation fix
- Done (updated): Combined with #35 in memalign workaround port
41. 4e33316f65 2017-05-25 malloc: Turn on DEBUG when enabling unit tests
- Already covered: Combined with #28, #63 at line 555
42. f1896c45cb 2017-07-24 spl: make SPL and normal u-boot stage use independent SYS_MALLOC_F_LEN
- Already covered: Use CONFIG_IS_ENABLED and CONFIG_VAL at line 6410
43. a874cac3b4 2017-11-10 malloc: don't compare pointers to 0
- Not needed: New dlmalloc uses proper NULL comparisons
44. ee038c58d5 2018-05-18 malloc: Use malloc simple before malloc is fully initialized in memalign()
- Already covered: memalign_simple redirect at line 5367
45. 7cbd2d2e32 2018-11-18 malloc_simple: Add logging of allocations
- Not needed: Changes to malloc_simple.c, not dlmalloc.c
46. 4c6be01c27 2019-03-27 malloc: Fix memalign not honoring alignment prior to full malloc init
- Already covered: Uses memalign_simple at line 5367
47. bb71a2d9dc 2019-10-25 dlmalloc: calloc: fix zeroing early allocations
- Done (updated): Port to dlcalloc() at line 4857
48. cfda60f99a 2020-02-03 sandbox: Use a prefix for all allocation functions
- Done: USE_DL_PREFIX and reverse mappings in malloc.h
49. be621c11b9 2020-04-15 dlmalloc: remove unit test support in SPL
- Already covered: CONFIG_IS_ENABLED(UNIT_TEST) at line 554
50. 9297e366d6 2020-04-29 malloc: dlmalloc: add an ability for the malloc to be re-init/init multiple times
- Not needed: No boards use CONFIG_SYS_MALLOC_DEFAULT_TO_INIT
51. f7ae49fc4f 2020-05-10 common: Drop log.h from common header
- Already covered: Includes log.h at line 559
52. 401d1c4f5d 2020-10-30 common: Drop asm/global_data.h from common header
- Already covered: Includes asm/global_data.h at line 557
53. c6bf4f3898 2021-02-10 malloc: adjust memcpy() and memset() definitions.
- Not needed: New malloc.h doesn't declare memset/memcpy
54. c197f6e279 2021-03-15 malloc: Export malloc_simple_info()
- Not needed: Only changes malloc.h, not dlmalloc.c
55. 5ad9220bf7 2021-05-29 malloc: add SPDX license identifiers
- Not needed: New dlmalloc has MIT-0 license from upstream
56. bdaeea1b68 2022-03-23 malloc: Annotate allocator for valgrind
- Done (updated): Valgrind annotations in dlmalloc(), dlfree(), dlrealloc()
57. 62d638386c 2022-09-06 test: Support testing malloc() failures
- Done: malloc_testing/malloc_max_allocs in dlmalloc()
58. f88d48cc74 2023-02-27 dlmalloc: Fix a warning with clang-15
- Done: Add (void) to dlmalloc_stats() function definition
59. c9db9a2ef5 2023-08-25 dlmalloc: Add support for SPL_SYS_MALLOC_CLEAR_ON_INIT
- Already covered: Uses CONFIG_IS_ENABLED() in mem_malloc_init() from #32
60. 6a595c2f67 2023-09-06 common: malloc: Remove unused NEEDS_MANUAL_RELOC code bits
- Not needed: NEEDS_MANUAL_RELOC has been removed
61. ac897385bb 2023-10-02 Merge branch 'next'
- Not needed: Merge commit, no dlmalloc changes
62. 3d6d507514 2023-09-26 spl: Use SYS_MALLOC_F instead of SYS_MALLOC_F_LEN
- Already covered: Uses CONFIG_IS_ENABLED(SYS_MALLOC_F) throughout
63. 1786861415 2023-10-07 malloc: Enable assertions if UNIT_TEST is enabled
- Done (updated): Combined with #28, use 'DEBUG 1' for new dlmalloc
64. c82ff48115 2024-03-31 mcheck: prepare +1 tier for mcheck-wrappers, in dl-*alloc commands
- Done (updated): Added STATIC_IF_MCHECK and *_impl macros for dlmalloc 2.8.6
65. dfba071ddc 2024-03-31 mcheck: Use memset/memcpy instead of MALLOC_ZERO/MALLOC_COPY for mcheck.
- Done: Undef and redefine MALLOC_ZERO/MALLOC_COPY when mcheck enabled
66. 151493a875 2024-03-31 mcheck: integrate mcheck into dlmalloc.c
- Done: Added mcheck wrapper functions for dlmalloc, dlfree, dlrealloc, dlmemalign, dlcalloc
67. ae838768d7 2024-03-31 mcheck: support memalign
- Done: Implemented dlmemalign wrapper with mcheck hooks
68. 18c1bfafe0 2024-03-31 mcheck: add pedantic mode support
- Done: Added mcheck_pedantic_prehook() calls and mcheck_pedantic()/mcheck_check_all() API
69. a79fc7a79c 2024-04-27 common: Remove <common.h> and add needed includes
- Not needed: common.h has been removed
70. d678a59d2d 2024-05-18 Revert "Merge patch series "arm: dts: am62-beagleplay: Fix Beagleplay Ethernet""
- Not needed: common.h has been removed
71. 03de305ec4 2024-05-20 Restore patch series "arm: dts: am62-beagleplay: Fix Beagleplay Ethernet"
- Not needed: common.h has been removed
72. 910cef3d2f 2024-07-13 common: Remove duplicate newlines
- Not needed: New dlmalloc has its own formatting from upstream
73. 6627fbba20 2024-07-23 include: Remove duplicate newlines
- Not needed: New malloc.h has its own formatting from upstream
74. 04894f5ad5 2024-07-30 malloc: Support testing with realloc()
- Done: Combined with #57, malloc_testing check in dlrealloc()
75. 8642b2178d 2024-08-02 dlmalloc: Fix integer overflow in request2size()
- Not needed: New dlmalloc 2.8.6 uses MAX_REQUEST for robust overflow checks
76. 0a10b49206 2024-08-02 dlmalloc: Fix integer overflow in sbrk()
- Already covered: sbrk() checks bounds before memset in U-Boot section
77. 9b9368b5c4 2024-08-02 dlmalloc: Make sure allocation size is within malloc area
- Not needed: New dlmalloc 2.8.6 uses MAX_REQUEST for robust overflow checks
78. 41fecdc94e 2024-10-21 common: Tidy up how malloc() is inited
- Already covered: mem_malloc_init() uses map_sysmem in U-Boot section
79. 22f87ef530 2025-08-17 malloc: Avoid defining calloc()
- Done: Added SYS_MALLOC_SIMPLE section to malloc.h with calloc redirect
END
Co-developed-by: Claude <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
Simon Glass