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Commit 73bdf0a6 authored by Linus Torvalds's avatar Linus Torvalds Committed by H. Peter Anvin
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Introduce is_vmalloc_or_module_addr() and use with DEBUG_VIRTUAL 



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: default avatarH. Peter Anvin <hpa@zytor.com>
parent f61f1b57

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);