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Commit 1255a734 authored by Vincenzo Frascino's avatar Vincenzo Frascino Committed by Will Deacon
Browse files

arm64: compat: Refactor aarch32_alloc_vdso_pages() 



aarch32_alloc_vdso_pages() needs to be refactored to make it
easier to disable kuser helpers.

Divide the function in aarch32_alloc_kuser_vdso_page() and
aarch32_alloc_sigreturn_vdso_page().

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
[will: Inlined sigpage allocation to simplify error paths]
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent d1e5ca64

arch/arm64/kernel/vdso.c

+26 −26
Original line number Diff line number Diff line
@@ -68,43 +68,43 @@ static const struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = { 
	},

};



static int __init aarch32_alloc_vdso_pages(void)

static int aarch32_alloc_kuser_vdso_page(void)

{

	extern char __kuser_helper_start[], __kuser_helper_end[];

	extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];



	int kuser_sz = __kuser_helper_end - __kuser_helper_start;

	int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;

	unsigned long vdso_pages[C_PAGES];

	unsigned long vdso_page;



	vdso_pages[C_VECTORS] = get_zeroed_page(GFP_ATOMIC);

	if (!vdso_pages[C_VECTORS])

	vdso_page = get_zeroed_page(GFP_ATOMIC);

	if (!vdso_page)

		return -ENOMEM;



	vdso_pages[C_SIGPAGE] = get_zeroed_page(GFP_ATOMIC);

	if (!vdso_pages[C_SIGPAGE]) {

		free_page(vdso_pages[C_VECTORS]);

		return -ENOMEM;

	memcpy((void *)(vdso_page + 0x1000 - kuser_sz), __kuser_helper_start,

	       kuser_sz);

	aarch32_vdso_pages[C_VECTORS] = virt_to_page(vdso_page);

	flush_dcache_page(aarch32_vdso_pages[C_VECTORS]);

	return 0;

}



	/* kuser helpers */

	memcpy((void *)(vdso_pages[C_VECTORS] + 0x1000 - kuser_sz),

	       __kuser_helper_start,

	       kuser_sz);

static int __init aarch32_alloc_vdso_pages(void)

{

	extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];

	int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;

	unsigned long sigpage;

	int ret;



	/* sigreturn code */

	memcpy((void *)vdso_pages[C_SIGPAGE], __aarch32_sigret_code_start,

	       sigret_sz);

	sigpage = get_zeroed_page(GFP_ATOMIC);

	if (!sigpage)

		return -ENOMEM;



	flush_icache_range(vdso_pages[C_VECTORS],

			   vdso_pages[C_VECTORS] + PAGE_SIZE);

	flush_icache_range(vdso_pages[C_SIGPAGE],

			   vdso_pages[C_SIGPAGE] + PAGE_SIZE);

	memcpy((void *)sigpage, __aarch32_sigret_code_start, sigret_sz);

	aarch32_vdso_pages[C_SIGPAGE] = virt_to_page(sigpage);

	flush_dcache_page(aarch32_vdso_pages[C_SIGPAGE]);



	aarch32_vdso_pages[C_VECTORS] = virt_to_page(vdso_pages[C_VECTORS]);

	aarch32_vdso_pages[C_SIGPAGE] = virt_to_page(vdso_pages[C_SIGPAGE]);

	ret = aarch32_alloc_kuser_vdso_page();

	if (ret)

		free_page(sigpage);



	return 0;

	return ret;

}

arch_initcall(aarch32_alloc_vdso_pages);