Commit 4fcc6366 authored by Jordan Niethe's avatar Jordan Niethe Committed by Michael Ellerman
Browse files

powerpc/modules: Make module_alloc() Strict Module RWX aware 



Make module_alloc() use PAGE_KERNEL protections instead of
PAGE_KERNEL_EXEX if Strict Module RWX is enabled.

Signed-off-by: default avatarJordan Niethe <jniethe5@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210609013431.9805-4-jniethe5@gmail.com
parent 71a5b3db

arch/powerpc/include/asm/mmu.h

+5 −0
Original line number Diff line number Diff line
@@ -345,6 +345,11 @@ static inline bool strict_kernel_rwx_enabled(void) 
	return false;

}

#endif



static inline bool strict_module_rwx_enabled(void)

{

	return IS_ENABLED(CONFIG_STRICT_MODULE_RWX) && strict_kernel_rwx_enabled();

}

#endif /* !__ASSEMBLY__ */



/* The kernel use the constants below to index in the page sizes array.

arch/powerpc/kernel/module.c

+3 −1
Original line number Diff line number Diff line
@@ -92,12 +92,14 @@ int module_finalize(const Elf_Ehdr *hdr, 
static __always_inline void *

__module_alloc(unsigned long size, unsigned long start, unsigned long end)

{

	pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;



	/*

	 * Don't do huge page allocations for modules yet until more testing

	 * is done. STRICT_MODULE_RWX may require extra work to support this

	 * too.

	 */

	return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL, PAGE_KERNEL_EXEC,

	return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL, prot,

				    VM_FLUSH_RESET_PERMS | VM_NO_HUGE_VMAP,

				    NUMA_NO_NODE, __builtin_return_address(0));

}