Messages in this thread | | | Date | Wed, 6 Sep 2023 01:11:38 -0700 | Subject | Re: [PATCH] lockdep: Fix static memory detection even more | From | Guenter Roeck <> |
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On 9/6/23 00:18, Helge Deller wrote: > * Guenter Roeck <linux@roeck-us.net>: >> On 9/3/23 14:11, Helge Deller wrote: >>> * Guenter Roeck <linux@roeck-us.net>: >>>> 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@gmx.de> >>>>> 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. >>> >>> Does this happens with CONFIG_SMP=n ? >>> If so, I think the untested patch below might fix the issue. >>> >> >> No, this is loongarch:defconfig with various debug options enabled. >> That has CONFIG_SMP=y. > > Could you apply below patch and verify with the contents of the > System.map file where the lock is located ? > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index e85b5ad3e206..db0a301f9740 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -969,7 +969,7 @@ static bool assign_lock_key(struct lockdep_map *lock) > else { > /* Debug-check: all keys must be persistent! */ > debug_locks_off(); > - pr_err("INFO: trying to register non-static key.\n"); > + pr_err("INFO: trying to register non-static key at %08lx.\n", addr); > pr_err("The code is fine but needs lockdep annotation, or maybe\n"); > pr_err("you didn't initialize this object before use?\n"); > pr_err("turning off the locking correctness validator.\n");
90000000015602d0 D __la_abs_end ... 90000000016815c0 d fill_pool_map.3 <--- lock pointer ... 9000000001770000 T __init_begin
Guenter
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