Introduce is_vmalloc_or_module_addr() and use with DEBUG_VIRTUAL (73bdf0a6) · Commits · 戴 / test

Impact: crash on module insertion with CONFIG_DEBUG_VIRTUAL We would incorrectly BUG due to: VIRTUAL_BUG_ON(!is_vmalloc_addr(vmalloc_addr) && !is_module_address(addr)); ... because, at least on x86-64, is_module_address() doesn't do what it should. This patch introduces is_vmalloc_or_module_addr(), which is what we really want anyway, and uses it instead. Signed-off-by:

H. Peter Anvin <hpa@zytor.com>

mm/vmalloc.c

+16 −2

Original line number	Diff line number	Diff line
		@@ -168,6 +168,21 @@ int map_vm_area(struct vm_struct area, pgprot_t prot, struct page **pages)
		}
		EXPORT_SYMBOL_GPL(map_vm_area);

		static inline int is_vmalloc_or_module_addr(const void *x)
		{
		/*
		* x86-64 and sparc64 put modules in a special place,
		* and fall back on vmalloc() if that fails. Others
		* just put it in the vmalloc space.
		*/
		#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
		unsigned long addr = (unsigned long)x;
		if (addr >= MODULES_VADDR && addr < MODULES_END)
		return 1;
		#endif
		return is_vmalloc_addr(x);
		}

		/*
		* Map a vmalloc()-space virtual address to the physical page.
		*/
		@@ -184,8 +199,7 @@ struct page vmalloc_to_page(const void vmalloc_addr)
		* XXX we might need to change this if we add VIRTUAL_BUG_ON for
		* architectures that do not vmalloc module space
		*/
		VIRTUAL_BUG_ON(!is_vmalloc_addr(vmalloc_addr) &&
		!is_module_address(addr));
		VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));

		if (!pgd_none(*pgd)) {
		pud = pud_offset(pgd, addr);

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