Re: [PATCH 1/3] init: Declare rodata_enabled and mark_rodata_ro() at all time

[Christophe Leroy]

Le 30/01/2024 à 10:16, Chen-Yu Tsai a écrit :
> [Vous ne recevez pas souvent de courriers de wenst@xxxxxxxxxxxx. D?couvrez pourquoi ceci est important ? https://aka.ms/LearnAboutSenderIdentification ]
> 
> Hi,
> 
> On Mon, Jan 29, 2024 at 12:09:50PM -0800, Luis Chamberlain wrote:
>> On Thu, Dec 21, 2023 at 10:02:46AM +0100, Christophe Leroy wrote:
>>> Declaring rodata_enabled and mark_rodata_ro() at all time
>>> helps removing related #ifdefery in C files.
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
>>
>> Very nice cleanup, thanks!, applied and pushed
>>
>>    Luis
> 
> On next-20240130, which has your modules-next branch, and thus this
> series and the other "module: Use set_memory_rox()" series applied,
> my kernel crashes in some very weird way. Reverting your branch
> makes the crash go away.
> 
> I thought I'd report it right away. Maybe you folks would know what's
> happening here? This is on arm64.

That's strange, it seems to bug in module_bug_finalize() which is 
_before_ calls to module_enable_ro() and such.

Can you try to revert the 6 patches one by one to see which one 
introduces the problem ?

In reality, only patch 677bfb9db8a3 really change things. Other ones are 
more on less only cleanup.

Thanks
Christophe


> 
> [   10.481015] Unable to handle kernel paging request at virtual address ffffffde85245d30
> [   10.490369] KASAN: maybe wild-memory-access in range [0x000000f42922e980-0x000000f42922e987]
> [   10.503744] Mem abort info:
> [   10.509383]   ESR = 0x0000000096000047
> [   10.514400]   EC = 0x25: DABT (current EL), IL = 32 bits
> [   10.522366]   SET = 0, FnV = 0
> [   10.526343]   EA = 0, S1PTW = 0
> [   10.530695]   FSC = 0x07: level 3 translation fault
> [   10.537081] Data abort info:
> [   10.540839]   ISV = 0, ISS = 0x00000047, ISS2 = 0x00000000
> [   10.546456]   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
> [   10.551726]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [   10.557612] swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000041f98000
> [   10.565214] [ffffffde85245d30] pgd=100000023ffff003, p4d=100000023ffff003, pud=100000023ffff003, pmd=10000001121eb003, pte=0000000000000000
> [   10.578887] Internal error: Oops: 0000000096000047 [#1] PREEMPT SMP
> [   10.585815] Modules linked in:
> [   10.590235] CPU: 6 PID: 195 Comm: (udev-worker) Tainted: G    B              6.8.0-rc2-next-20240130-02908-ge8ad01d60927-dirty #163 3f2318148ecc5fa70d1092c2b874f9b59bdb7d60
> [   10.607021] Hardware name: Google Tentacruel board (DT)
> [   10.613607] pstate: a0400009 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [   10.621954] pc : module_bug_finalize+0x118/0x148
> [   10.626823] lr : module_bug_finalize+0x118/0x148
> [   10.631463] sp : ffffffc0820478d0
> [   10.631466] x29: ffffffc0820478d0 x28: ffffffc082047ca0 x27: ffffffde8d7d31a0
> [   10.631477] x26: ffffffde85223780 x25: 0000000000000000 x24: ffffffde8c413cc0
> [   10.631486] x23: ffffffde8dfcec80 x22: ffffffde8dfce000 x21: ffffffde85223ba8
> [   10.631495] x20: ffffffde85223780 x19: ffffffde85245d28 x18: 0000000000000000
> [   10.631504] x17: ffffffde8aa15938 x16: ffffffde8aabdd90 x15: ffffffde8aab8124
> [   10.631513] x14: ffffffde8acdd380 x13: 0000000041b58ab3 x12: ffffffbbd1bf9d91
> [   10.631522] x11: 1ffffffbd1bf9d90 x10: ffffffbbd1bf9d90 x9 : dfffffc000000000
> [   10.631531] x8 : 000000442e406270 x7 : ffffffde8dfcec87 x6 : 0000000000000001
> [   10.631539] x5 : ffffffde8dfcec80 x4 : 0000000000000000 x3 : ffffffde8bbadf08
> [   10.631548] x2 : 0000000000000001 x1 : ffffffde8eaff080 x0 : 0000000000000000
> [   10.631556] Call trace:
> [   10.631559]  module_bug_finalize+0x118/0x148
> [   10.631565]  load_module+0x25ec/0x2a78
> [   10.631572]  __do_sys_init_module+0x234/0x418
> [   10.631578]  __arm64_sys_init_module+0x4c/0x68
> [   10.631584]  invoke_syscall+0x68/0x198
> [   10.631589]  el0_svc_common.constprop.0+0x11c/0x150
> [   10.631594]  do_el0_svc+0x38/0x50
> [   10.631598]  el0_svc+0x50/0xa0
> [   10.631604]  el0t_64_sync_handler+0x120/0x130
> [   10.631609]  el0t_64_sync+0x1a8/0x1b0
> [   10.631619] Code: 97c5418e c89ffef5 91002260 97c53ca7 (f9000675)
> [   10.631624] ---[ end trace 0000000000000000 ]---
> [   10.642965] Kernel panic - not syncing: Oops: Fatal exception
> [   10.642975] SMP: stopping secondary CPUs
> [   10.648339] Kernel Offset: 0x1e0a800000 from 0xffffffc080000000
> [   10.648343] PHYS_OFFSET: 0x40000000
> [   10.648345] CPU features: 0x0,c0000061,7002814a,2100720b
> [   10.648350] Memory Limit: none
>