Re: [PATCH v2 4/7] arm64/modules: Add rlimit checking for arm64 modules

From: Jessica Yu
Date: Fri Oct 12 2018 - 10:33:04 EST


+++ Dave Hansen [11/10/18 16:47 -0700]:
On 10/11/2018 04:31 PM, Rick Edgecombe wrote:
+ if (check_inc_mod_rlimit(size))
+ return NULL;
+
p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
module_alloc_base + MODULES_VSIZE,
gfp_mask, PAGE_KERNEL_EXEC, 0,
@@ -65,6 +68,8 @@ void *module_alloc(unsigned long size)
return NULL;
}

+ update_mod_rlimit(p, size);

Is there a reason we couldn't just rename all of the existing per-arch
module_alloc() calls to be called, say, "arch_module_alloc()", then put
this new rlimit code in a generic helper that does:


if (check_inc_mod_rlimit(size))
return NULL;

p = arch_module_alloc(...);

...

update_mod_rlimit(p, size);


I second this suggestion. Just make module_{alloc,memfree} generic,
non-weak functions that call the rlimit helpers in addition to the
arch-specific arch_module_{alloc,memfree} functions.

Jessica