Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 10 Apr 2017 08:56:06 -0700 | Subject | Re: [patch 2/3] x86/vdso: Plug race between mapping and ELF header setup |
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On Mon, Apr 10, 2017 at 8:14 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > The vsyscall32 sysctl can racy against a concurrent fork when it switches > from disabled to enabled: > > arch_setup_additional_pages() > if (vdso32_enabled) > --> No mapping > sysctl.vsysscall32() > --> vdso32_enabled = true > create_elf_tables() > ARCH_DLINFO_IA32 > if (vdso32_enabled) { > --> Add VDSO entry with NULL pointer > > Make ARCH_DLINFO_IA32 check whether the VDSO mapping has been set up for > the newly forked process or not.
Acked-by: Andy Lutomirski <luto@kernel.org>
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