[PATCH v2 11/28] arm64: compat: Refactor aarch32_alloc_vdso_pages()
From: Vincenzo Frascino <vincenzo.frascino@arm.com>
Date: 2018-11-29 17:09:08
Also in:
linux-arch
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
aarch32_alloc_vdso_pages() needs to the refactored to make it easier to disable kuser helpers. This patch divides the function in aarch32_alloc_kuser_vdso_page() and aarch32_alloc_sigreturn_vdso_page(). Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <redacted> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> --- arch/arm64/kernel/vdso.c | 49 ++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 17 deletions(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 88b674079d07..cee7205eefc5 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c@@ -74,40 +74,55 @@ static const struct vm_special_mapping aarch32_vdso_spec[2] = { }, }; -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[2]; - - vdso_pages[0] = get_zeroed_page(GFP_ATOMIC); - if (!vdso_pages[0]) - return -ENOMEM; + unsigned long vdso_page; - vdso_pages[1] = get_zeroed_page(GFP_ATOMIC); - if (!vdso_pages[1]) + vdso_page = get_zeroed_page(GFP_ATOMIC); + if (!vdso_page) return -ENOMEM; /* kuser helpers */ - memcpy((void *)(vdso_pages[0] + 0x1000 - kuser_sz), + memcpy((void *)(vdso_page + 0x1000 - kuser_sz), __kuser_helper_start, kuser_sz); + flush_icache_range(vdso_page, vdso_page + PAGE_SIZE); + + aarch32_vdso_pages[0] = virt_to_page(vdso_page); + + return 0; +} + +static int aarch32_alloc_sigreturn_vdso_page(void) +{ + extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; + int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; + unsigned long vdso_page; + + vdso_page = get_zeroed_page(GFP_ATOMIC); + if (!vdso_page) + return -ENOMEM; + /* sigreturn code */ - memcpy((void *)vdso_pages[1], + memcpy((void *)vdso_page, __aarch32_sigret_code_start, sigret_sz); - flush_icache_range(vdso_pages[0], vdso_pages[0] + PAGE_SIZE); - flush_icache_range(vdso_pages[1], vdso_pages[1] + PAGE_SIZE); + flush_icache_range(vdso_page, vdso_page + PAGE_SIZE); - aarch32_vdso_pages[0] = virt_to_page(vdso_pages[0]); - aarch32_vdso_pages[1] = virt_to_page(vdso_pages[1]); + aarch32_vdso_pages[1] = virt_to_page(vdso_page); return 0; + +} + +static int __init aarch32_alloc_vdso_pages(void) +{ + return aarch32_alloc_kuser_vdso_page() & + aarch32_alloc_sigreturn_vdso_page(); } arch_initcall(aarch32_alloc_vdso_pages);
--
2.19.2
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