Messages in this thread | | | Date | Tue, 13 Apr 2021 22:00:30 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH] x86/kprobes: Simplify alloc_insn_page() with __vmalloc_node_range |
| |
Hi,
On Tue, 13 Apr 2021 18:03:24 +0800 Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote:
> Use the __vmalloc_node_range() to simplify x86's alloc_insn_page() > implementation.
Have you checked this is equivarent to the original code on all architecture? IIRC, some arch has a special module_alloc(), thus I NACKed similar patch previously.
Thank you,
> > Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> > --- > arch/x86/kernel/kprobes/core.c | 24 ++++-------------------- > 1 file changed, 4 insertions(+), 20 deletions(-) > > diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c > index df776cdca327..75081f3dbe44 100644 > --- a/arch/x86/kernel/kprobes/core.c > +++ b/arch/x86/kernel/kprobes/core.c > @@ -383,26 +383,10 @@ static int prepare_boost(kprobe_opcode_t *buf, struct kprobe *p, > /* Make page to RO mode when allocate it */ > void *alloc_insn_page(void) > { > - void *page; > - > - page = module_alloc(PAGE_SIZE); > - if (!page) > - return NULL; > - > - set_vm_flush_reset_perms(page); > - /* > - * First make the page read-only, and only then make it executable to > - * prevent it from being W+X in between. > - */ > - set_memory_ro((unsigned long)page, 1); > - > - /* > - * TODO: Once additional kernel code protection mechanisms are set, ensure > - * that the page was not maliciously altered and it is still zeroed. > - */ > - set_memory_x((unsigned long)page, 1); > - > - return page; > + return __vmalloc_node_range(PAGE_SIZE, PAGE_SIZE, VMALLOC_START, > + VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX, > + VM_FLUSH_RESET_PERMS, NUMA_NO_NODE, > + __builtin_return_address(0)); > } > > /* Recover page to RW mode before releasing it */ > -- > 2.31.0 >
-- Masami Hiramatsu <mhiramat@kernel.org>
| |