vdso_enabled can be set to arbitrary integer values via the kernel command
line 'vdso32=' parameter or via 'sysctl abi.vsyscall32'.
load_vdso32() only maps VDSO if vdso_enabled == 1, but ARCH_DLINFO_IA32
merily checks for vdso_enabled != 0. As a consequence the AT_SYSINFO_EHDR
auxiliary vector for the VDSO_ENTRY is emitted with a NULL pointer which
causes a segfault when the application tries to use the VDSO.
Restrict the valid arguments on the command line and the sysctl to 0 and 1.
Fixes: b0b49f2673 ("x86, vdso: Remove compat vdso support")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Cc: Roland McGrath <roland@redhat.com>
Link: http://lkml.kernel.org/r/1491424561-7187-1-git-send-email-minipli@googlemail.com
Link: http://lkml.kernel.org/r/20170410151723.518412863@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move them to a separate header and have the following
dependency:
x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h
This makes it easier to use the header in asm code and not
include the whole cpufeature.h and add guards for asm.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
32-bit userspace will now always see the same vDSO, which is
exactly what used to be the int80 vDSO. Subsequent patches will
clean it up and make it support SYSENTER and SYSCALL using
alternatives.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/e7e6b3526fa442502e6125fe69486aab50813c32.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
