Re: [PATCH] lockdep: Fix static memory detection even more

From: Guenter Roeck
Date: Sun Sep 03 2023 - 15:43:11 EST

Hi,

On Sat, Aug 12, 2023 at 05:48:52PM +0200, Helge Deller wrote:
> On the parisc architecture, lockdep reports for all static objects which
> are in the __initdata section (e.g. "setup_done" in devtmpfs,
> "kthreadd_done" in init/main.c) this warning:
>
> INFO: trying to register non-static key.
>
> The warning itself is wrong, because those objects are in the __initdata
> section, but the section itself is on parisc outside of range from
> _stext to _end, which is why the static_obj() functions returns a wrong
> answer.
>
> While fixing this issue, I noticed that the whole existing check can
> be simplified a lot.
> Instead of checking against the _stext and _end symbols (which include
> code areas too) just check for the .data and .bss segments (since we check a
> data object). This can be done with the existing is_kernel_core_data()
> macro.
>
> In addition objects in the __initdata section can be checked with
> init_section_contains().
>
> This partly reverts and simplifies commit bac59d18c701 ("x86/setup: Fix static
> memory detection").
>
> Tested on x86-64 and parisc.
>
> Signed-off-by: Helge Deller <deller@xxxxxx>
> Fixes: bac59d18c701 ("x86/setup: Fix static memory detection")

On loongarch, this patch results in the following backtrace.

EFI stub: Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path
EFI stub: Exiting boot services
[ 0.000000] INFO: trying to register non-static key.
[ 0.000000] The code is fine but needs lockdep annotation, or maybe
[ 0.000000] you didn't initialize this object before use?
[ 0.000000] turning off the locking correctness validator.
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0+ #1
[ 0.000000] Stack : 0000000000000000 0000000000000000 9000000000223d6c 9000000001df0000
[ 0.000000] 9000000001df39a0 9000000001df39a8 0000000000000000 0000000000000000
[ 0.000000] 9000000001df39a8 0000000000000001 0000000000000000 900000000154b910
[ 0.000000] fffffffffffffffe 9000000001df39a8 0000000000000000 0000000000000000
[ 0.000000] 0000000000000001 0000000000000003 0000000000000010 0000000000000030
[ 0.000000] 0000000000000063 0000000000000001 0000000000000000 0000000000000000
[ 0.000000] 0000000000000000 0000000000000000 9000000001c60650 9000000001e12000
[ 0.000000] 0000000000000000 9000000001560bc0 0000000000000000 9000000002ee6000
[ 0.000000] 0000000000000000 0000000000000000 9000000000223d84 0000000000000000
[ 0.000000] 00000000000000b0 0000000000000004 0000000000000000 0000000000000800
[ 0.000000] ...
[ 0.000000] Call Trace:
[ 0.000000] [<9000000000223d84>] show_stack+0x5c/0x180
[ 0.000000] [<900000000153e0b4>] dump_stack_lvl+0x88/0xd0
[ 0.000000] [<90000000002bc548>] register_lock_class+0x768/0x770
[ 0.000000] [<90000000002bc710>] __lock_acquire+0xb0/0x2a18
[ 0.000000] [<90000000002bba1c>] lock_acquire+0x11c/0x328
[ 0.000000] [<9000000000b34a60>] __debug_object_init+0x60/0x244
[ 0.000000] [<9000000000337f94>] init_cgroup_housekeeping+0xe8/0x144
[ 0.000000] [<900000000033e364>] init_cgroup_root+0x38/0xa0
[ 0.000000] [<90000000017801ac>] cgroup_init_early+0x44/0x16c
[ 0.000000] [<9000000001770758>] start_kernel+0x50/0x624
[ 0.000000] [<90000000015410b4>] kernel_entry+0xb4/0xc4

Reverting it fixes the problem. Bisect log attached.

This is also seen in v6.5.y and v6.4.y since the patch has been applied
to those branches.

Guenter

---
# bad: [99d99825fc075fd24b60cc9cf0fb1e20b9c16b0f] Merge tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
# good: [1c59d383390f970b891b503b7f79b63a02db2ec5] Merge tag 'linux-kselftest-nolibc-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
git bisect start '99d99825fc07' '1c59d383390f'
# bad: [53ea7f624fb91074c2f9458832ed74975ee5d64c] Merge tag 'xfs-6.6-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
git bisect bad 53ea7f624fb91074c2f9458832ed74975ee5d64c
# good: [aa05346dad4b37d068cf9144f0a1236757816886] Merge branch 'iep-drver-timestamping-support'
git bisect good aa05346dad4b37d068cf9144f0a1236757816886
# good: [651a00bc56403161351090a9d7ddbd7095975324] Merge tag 'slab-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
git bisect good 651a00bc56403161351090a9d7ddbd7095975324
# good: [b96a3e9142fdf346b05b20e867b4f0dfca119e96] Merge tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
git bisect good b96a3e9142fdf346b05b20e867b4f0dfca119e96
# bad: [3d3dfeb3aec7b612d266d500c82054f1fded4980] Merge tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linux
git bisect bad 3d3dfeb3aec7b612d266d500c82054f1fded4980
# bad: [c1b7fcf3f6d94c2c3528bf77054bf174a5ef63d7] Merge tag 'for-6.6/io_uring-2023-08-28' of git://git.kernel.dk/linux
git bisect bad c1b7fcf3f6d94c2c3528bf77054bf174a5ef63d7
# bad: [dce8f8ed1de1d9d6d27c5ccd202ce4ec163b100c] document while_each_thread(), change first_tid() to use for_each_thread()
git bisect bad dce8f8ed1de1d9d6d27c5ccd202ce4ec163b100c
# good: [02d7f74a04b1299ab2a0a9095f0e2d5aa3aed553] lib/bch.c: use bitrev instead of internal logic
git bisect good 02d7f74a04b1299ab2a0a9095f0e2d5aa3aed553
# good: [79939c4a79bc643d399bd3fdd0f87100ea6b4362] scripts/gdb/slab: add slab support
git bisect good 79939c4a79bc643d399bd3fdd0f87100ea6b4362
# bad: [5ffd2c37cb7a53d52099e5ed1fd7ccbc9e358791] kill do_each_thread()
git bisect bad 5ffd2c37cb7a53d52099e5ed1fd7ccbc9e358791
# good: [665536092355f17f0e2ea291eec70f9787dccd32] lib/vsprintf: declare no_hash_pointers in sprintf.h
git bisect good 665536092355f17f0e2ea291eec70f9787dccd32
# bad: [ef815d2cba782e96b9aad9483523d474ed41c62a] treewide: drop CONFIG_EMBEDDED
git bisect bad ef815d2cba782e96b9aad9483523d474ed41c62a
# bad: [0a6b58c5cd0dfd7961e725212f0fc8dfc5d96195] lockdep: fix static memory detection even more
git bisect bad 0a6b58c5cd0dfd7961e725212f0fc8dfc5d96195
# first bad commit: [0a6b58c5cd0dfd7961e725212f0fc8dfc5d96195] lockdep: fix static memory detection even more