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

[Helge Deller]

On 8/14/23 16:17, Peter Zijlstra wrote:
> On Mon, Aug 14, 2023 at 09:40:42PM +0800, kernel test robot wrote:
> > Hello,
> >
> > kernel test robot noticed "BUG:key#has_not_been_registered" on:
> >
> > commit: 94d4413e506da48ea18f1cc982202874d35c76b1 ("[PATCH] lockdep: Fix static memory detection even more")
> > url: https://github.com/intel-lab-lkp/linux/commits/Helge-Deller/lockdep-Fix-static-memory-detection-even-more/20230812-235022
> > base: https://git.kernel.org/cgit/linux/kernel/git/akpm/mm.git mm-everything
> > patch link: https://lore.kernel.org/all/ZNep5EcYskP9HtGD@p100/
> > patch subject: [PATCH] lockdep: Fix static memory detection even more
> >
> > in testcase: boot
> >
> > compiler: gcc-12
> > test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> >
> > (please refer to attached dmesg/kmsg for entire log/backtrace)
> >
> >
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> > | Closes: https://lore.kernel.org/oe-lkp/202308141646.d3160c77-oliver.sang@xxxxxxxxx
> >
> >
> >
> > [    0.575811][    T1] BUG: key b35c282c has not been registered!
> > [    0.576580][    T1] ------------[ cut here ]------------
> > [    0.577216][    T1] DEBUG_LOCKS_WARN_ON(1)
> > [    0.577236][    T1] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:4888 lockdep_init_map_type+0x155/0x250
> > [    0.578389][    T1] Modules linked in:
> > [    0.578856][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc4-00587-g94d4413e506d #2
>
> > [    0.595653][    T1]  __kernfs_create_file+0x6a/0xe0
> > [    0.596244][    T1]  sysfs_add_bin_file_mode_ns+0x4e/0xc0
> > [    0.596891][    T1]  sysfs_create_bin_file+0x5c/0x90
> > [    0.597496][    T1]  ? nsproxy_cache_init+0x30/0x30
> > [    0.598090][    T1]  ksysfs_init+0x5c/0x90
>
> Problem seems to be __ro_after_init. Your patch only considers
> is_kernel_core_data(), which seems to not include these other fancy data
> sections we have.

Thanks for that hint!
So, adding "if (is_kernel_rodata(addr))..."
I'll test and send a new patch.

Helge