Messages in this thread | | | Date | Wed, 16 Nov 2022 20:25:21 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH v4 2/8] riscv/kprobe: Allocate detour buffer from module area |
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On Sun, 6 Nov 2022 18:03:10 +0800 Chen Guokai <chenguokai17@mails.ucas.ac.cn> wrote:
> @@ -84,6 +85,30 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) > } > > #ifdef CONFIG_MMU > +#if defined(CONFIG_OPTPROBES) && defined(CONFIG_64BIT) > +void *alloc_optinsn_page(void) > +{ > + void *page; > + > + page = __vmalloc_node_range(PAGE_SIZE, 1, MODULES_VADDR, > + MODULES_END, GFP_KERNEL, > + PAGE_KERNEL, 0, NUMA_NO_NODE, > + __builtin_return_address(0)); > + 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); > + set_memory_x((unsigned long)page, 1);
FYI, the above combination is going to be going away:
https://lore.kernel.org/all/Y10OyLCLAAS6rsZv@hirez.programming.kicks-ass.net/
-- Steve
> + > + return page; > +} > +#endif > +
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