Hi Christophe, On 31.01.2024 12:58, Christophe Leroy wrote: > Le 30/01/2024 à 18:48, Marek Szyprowski a écrit : >> [Vous ne recevez pas souvent de courriers de m.szyprowski@xxxxxxxxxxx. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ] >> >> On 30.01.2024 12:03, Christophe Leroy wrote: >>> 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 ] >>>> >>>> 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. >> I've also run into this issue with today's (20240130) linux-next on my >> test farm. The issue is not fully reproducible, so it was a bit hard to >> bisect it automatically. I've spent some time on manual testing and it >> looks that reverting the following 2 commits on top of linux-next fixes >> the problem: >> >> 65929884f868 ("modules: Remove #ifdef CONFIG_STRICT_MODULE_RWX around >> rodata_enabled") >> 677bfb9db8a3 ("module: Don't ignore errors from set_memory_XX()") >> >> This in fact means that commit 677bfb9db8a3 is responsible for this >> regression, as 65929884f868 has to be reverted only because the latter >> depends on it. Let me know what I can do to help debugging this issue. >> > Thanks for the bisect. I suspect you hit one of the errors and something > goes wrong in the error path. > > To confirm this assumption, could you try with the following change on > top of everything ? Yes, this is the problem. I've added printing a mod->name to the log. Here is a log from kernel build from next-20240130 (sometimes it even boots to shell): # dmesg | grep module_set_memory [ 8.061525] module_set_memory(6, 0000000000000000, 0) name ipv6 returned -22 [ 8.067543] WARNING: CPU: 3 PID: 1 at kernel/module/strict_rwx.c:22 module_set_memory+0x9c/0xb8 [ 8.097821] pc : module_set_memory+0x9c/0xb8 [ 8.102068] lr : module_set_memory+0x9c/0xb8 [ 8.183101] module_set_memory+0x9c/0xb8 [ 8.472862] module_set_memory(6, 0000000000000000, 0) name x_tables returned -22 [ 8.479215] WARNING: CPU: 2 PID: 1 at kernel/module/strict_rwx.c:22 module_set_memory+0x9c/0xb8 [ 8.510978] pc : module_set_memory+0x9c/0xb8 [ 8.515225] lr : module_set_memory+0x9c/0xb8 [ 8.596259] module_set_memory+0x9c/0xb8 [ 10.529879] module_set_memory(6, 0000000000000000, 0) name dm_mod returned -22 [ 10.536087] WARNING: CPU: 3 PID: 127 at kernel/module/strict_rwx.c:22 module_set_memory+0x9c/0xb8 [ 10.568254] pc : module_set_memory+0x9c/0xb8 [ 10.572501] lr : module_set_memory+0x9c/0xb8 [ 10.653535] module_set_memory+0x9c/0xb8 [ 10.853177] module_set_memory(6, 0000000000000000, 0) name fuse returned -22 [ 10.859196] WARNING: CPU: 5 PID: 130 at kernel/module/strict_rwx.c:22 module_set_memory+0x9c/0xb8 [ 10.891382] pc : module_set_memory+0x9c/0xb8 [ 10.895629] lr : module_set_memory+0x9c/0xb8 [ 10.976663] module_set_memory+0x9c/0xb8 > diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c > index a14df9655dbe..fdf8484154dd 100644 > --- a/kernel/module/strict_rwx.c > +++ b/kernel/module/strict_rwx.c > @@ -15,9 +15,12 @@ static int module_set_memory(const struct module > *mod, enum mod_mem_type type, > int (*set_memory)(unsigned long start, int num_pages)) > { > const struct module_memory *mod_mem = &mod->mem[type]; > + int err; > > set_vm_flush_reset_perms(mod_mem->base); > - return set_memory((unsigned long)mod_mem->base, mod_mem->size >> > PAGE_SHIFT); > + err = set_memory((unsigned long)mod_mem->base, mod_mem->size >> > PAGE_SHIFT); > + WARN(err, "module_set_memory(%d, %px, %x) returned %d\n", type, > mod_mem->base, mod_mem->size, err); > + return err; > } > > /* > > > Thanks for your help > Christophe Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
