Hi,

Le 30/01/2024 à 18:48, Marek Szyprowski a écrit :

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Dear All,

On 30.01.2024 12:03, Christophe Leroy wrote:

quoted

Le 30/01/2024 à 10:16, Chen-Yu Tsai a écrit :

quoted

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On Mon, Jan 29, 2024 at 12:09:50PM -0800, Luis Chamberlain wrote:

quoted

On Thu, Dec 21, 2023 at 10:02:46AM +0100, Christophe Leroy wrote:

quoted

Declaring rodata_enabled and mark_rodata_ro() at all time
helps removing related #ifdefery in C files.

Signed-off-by: Christophe Leroy <redacted>

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 ?

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