Messages in this thread | | | Date | Fri, 18 Nov 2022 09:41:03 +0800 | Subject | Re: [PATCH v4 2/8] riscv/kprobe: Allocate detour buffer from module area | From | "liaochang (A)" <> |
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在 2022/11/17 9:25, Steven Rostedt 写道: > 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/
Thanks for reminding, i will use this API in next revision. > -- Steve > > >> + >> + return page; >> +} >> +#endif >> + >
-- BR, Liao, Chang
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