From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Wed, 28 Jan 2015 11:47:08 +0000 Subject: arm32 binaries work with CONFIG_COMPAT as root but not as user? In-Reply-To: References: <20150128112249.GD6646@e104818-lin.cambridge.arm.com> Message-ID: <20150128114708.GA9000@e104818-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jan 28, 2015 at 11:42:55AM +0000, Riku Voipio wrote: > On 28 January 2015 at 13:22, Catalin Marinas wrote: > > On Wed, Jan 28, 2015 at 10:52:21AM +0000, Riku Voipio wrote: > > What does this say: > cat /proc/sys/vm/mmap_min_addr > 65536 > > > # cat /proc/sys/vm/mmap_min_addr > > > > If it is 64K, it won't run 32-bit apps as non-root. > > echo 32768 > /proc/sys/vm/mmap_min_addr > > and indeed binaries work as expected. > > The ubuntu LTS 3.13 kernel has: > > /boot/config-3.13.0-39-generic:CONFIG_DEFAULT_MMAP_MIN_ADDR=65536 > > I need to check how the value ended up wrong on the 3.19-rc3 I tested. It may be set by some boot script on arm64 Ubuntu (so entirely in user space). -- Catalin