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authorAndy Lutomirski <luto@kernel.org>2015-12-29 20:12:21 -0800
committerIngo Molnar <mingo@kernel.org>2016-01-12 11:59:34 +0100
commit352b78c62f27b356b182008acd3117f3ee03ffd2 (patch)
treec7049a57f0db45444e58a0e8026f65f2b0d5e726
parent1745cbc5d0dee0749a6bc0ea8e872c5db0074061 (diff)
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 <luto@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/c99ac48681bad709ca7ad5ee899d9042a3af6b00.1451446564.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/entry/vdso/vma.c1
-rw-r--r--arch/x86/include/asm/mmu.h3
2 files changed, 3 insertions, 1 deletions
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;