[PATCH v2 4/7] arm64/modules: Add rlimit checking for arm64 modules
From: rick.p.edgecombe@intel.com (Edgecombe, Rick P)
Date: 2018-10-13 05:36:16
Also in:
linux-arch, linux-fsdevel, linux-mips, linux-s390, lkml, sparclinux
On Fri, 2018-10-12 at 16:32 +0200, Jessica Yu wrote:
quoted hunk ↗ jump to hunk
+++ Dave Hansen [11/10/18 16:47 -0700]:quoted
On 10/11/2018 04:31 PM, Rick Edgecombe wrote:quoted
+ 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
Ok, thanks. I am going to try another version of this with just a system wide BPF JIT limit based on the problems Jann brought up. I think it would be nice to have a module space limit, but as far as I know the only way today un-privlidged users could fill the space is from BPF JIT. Unless you see another purpose long term? Rick