Intel OpenBMC Linux kernel source tree (mirror) https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev 2014-12-18T11:12:26+00:00 2014-12-18T11:12:26+00:00 Andy Lutomirski luto@amacapital.net 2014-12-17T22:48:30+00:00 urn:sha1:3fb2f4237bb452eb4e98f6a5dbd5a445b4fed9d0 It turns out that there's a lurking ABI issue. GCC, when compiling this in a 32-bit program: struct user_desc desc = { .entry_number = idx, .base_addr = base, .limit = 0xfffff, .seg_32bit = 1, .contents = 0, /* Data, grow-up */ .read_exec_only = 0, .limit_in_pages = 1, .seg_not_present = 0, .useable = 0, }; will leave .lm uninitialized. This means that anything in the kernel that reads user_desc.lm for 32-bit tasks is unreliable. Revert the .lm check in set_thread_area(). The value never did anything in the first place. Fixes: 0e58af4e1d21 ("x86/tls: Disallow unusual TLS segments") Signed-off-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org # Only if 0e58af4e1d21 is backported Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/d7875b60e28c512f6a6fc0baf5714d58e7eaadbb.1418856405.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org> 2012-12-14T22:37:13+00:00 David Howells dhowells@redhat.com 2012-12-14T22:37:13+00:00 urn:sha1:af170c5061dd78512c469e6e2d211980cdb2c193 Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>