On Tue, Jun 16, 2020 at 12:42:30PM +0200, Christoph Hellwig wrote: > On Tue, Jun 16, 2020 at 12:40:32PM +0200, Peter Zijlstra wrote: > > On Tue, Jun 16, 2020 at 12:33:13PM +0200, Christoph Hellwig wrote: > > > sorry, s/ftrace/kprobes/. See my updated branch here: > > > > > > http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/module_alloc-cleanup > > > > Ah the insn slot page, yes. Didn't you just loose VM_FLUSH_RESET_PERMS > > there? > > Yes, we did. vmalloc_exec had it, but given that module_alloc didn't > allocate executable on x86 it didn't. I guess we should make sure it > is set by the low-level vmalloc code if exec permissions are set to > sort this mess out. I think something like this should solve the issue: -- diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h index e988bac0a4a1c3..716e4de44a8e78 100644 --- a/arch/x86/include/asm/module.h +++ b/arch/x86/include/asm/module.h @@ -13,4 +13,6 @@ struct mod_arch_specific { #endif }; +void *module_alloc_prot(unsigned long size, pgprot_t prot); + #endif /* _ASM_X86_MODULE_H */ diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c index 34b153cbd4acb4..4db6e655120960 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -65,8 +65,10 @@ static unsigned long int get_module_load_offset(void) } #endif -void *module_alloc(unsigned long size) +void *module_alloc_prot(unsigned long size, pgprot_t prot) { + unsigned int flags = (pgprot_val(prot) & _PAGE_NX) ? + 0 : VM_FLUSH_RESET_PERMS; void *p; if (PAGE_ALIGN(size) > MODULES_LEN) @@ -75,7 +77,7 @@ void *module_alloc(unsigned long size) p = __vmalloc_node_range(size, MODULE_ALIGN, MODULES_VADDR + get_module_load_offset(), MODULES_END, GFP_KERNEL, - PAGE_KERNEL, 0, NUMA_NO_NODE, + prot, flags, NUMA_NO_NODE, __builtin_return_address(0)); if (p && (kasan_module_alloc(p, size) < 0)) { vfree(p); @@ -85,6 +87,11 @@ void *module_alloc(unsigned long size) return p; } +void *module_alloc(unsigned long size) +{ + return module_alloc_prot(size, PAGE_KERNEL); +} + #ifdef CONFIG_X86_32 int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab,
