From 352b78c62f27b356b182008acd3117f3ee03ffd2 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Tue, 29 Dec 2015 20:12:21 -0800 Subject: [PATCH] x86/vdso: Track each mm's loaded vDSO image as well as its base As we start to do more intelligent things with the vDSO at runtime (as opposed to just at mm initialization time), we'll need to know which vDSO is in use. In principle, we could guess based on the mm type, but that's over-complicated and error-prone. Instead, just track it in the mmu context. Signed-off-by: Andy Lutomirski Reviewed-by: Kees Cook Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Quentin Casasnovas Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/c99ac48681bad709ca7ad5ee899d9042a3af6b00.1451446564.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/entry/vdso/vma.c | 1 + arch/x86/include/asm/mmu.h | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index b8f69e264ac4..80b021067bd6 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -121,6 +121,7 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr) text_start = addr - image->sym_vvar_start; current->mm->context.vdso = (void __user *)text_start; + current->mm->context.vdso_image = image; /* * MAYWRITE to allow gdb to COW and set breakpoints diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h index 55234d5e7160..1ea0baef1175 100644 --- a/arch/x86/include/asm/mmu.h +++ b/arch/x86/include/asm/mmu.h @@ -19,7 +19,8 @@ typedef struct { #endif struct mutex lock; - void __user *vdso; + void __user *vdso; /* vdso base address */ + const struct vdso_image *vdso_image; /* vdso image in use */ atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */ } mm_context_t; -- 2.45.2