Hi, On bootup of kernel 4.4.0 (and also current master) I get a report with a large number of W+X pages. Partial dmesg (for the Arch Linux kernel) below: [ 0.448748] Freeing unused kernel memory: 1188K (ffffffff818ee000 - ffffffff81a17000) [ 0.448749] Write protecting the kernel read-only data: 8192k [ 0.449564] Freeing unused kernel memory: 408K (ffff88000159a000 - ffff880001600000) [ 0.450100] Freeing unused kernel memory: 228K (ffff8800017c7000 - ffff880001800000) [ 0.450110] ------------[ cut here ]------------ [ 0.450112] WARNING: CPU: 0 PID: 1 at arch/x86/mm/dump_pagetables.c:225 note_page+0x5e1/0x780() [ 0.450113] x86/mm: Found insecure W+X mapping at address ffff880001800000/0xffff880001800000 [ 0.450114] Modules linked in: [ 0.450116] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.0-3-ARCH #1 [ 0.450117] Hardware name: Notebook P65_P67RGRERA/P65_P67RGRERA, BIOS 1.05.07 10/12/2015 [ 0.450118] 0000000000000000 00000000df3c3635 ffff880872287d48 ffffffff812c8a99 [ 0.450119] ffff880872287d90 ffff880872287d80 ffffffff810771c2 ffff880872287e90 [ 0.450121] 0000000000000163 0000000000000004 0000000000000000 0000000000000000 [ 0.450122] Call Trace: [ 0.450126] [] dump_stack+0x4b/0x72 [ 0.450127] [] warn_slowpath_common+0x82/0xc0 [ 0.450129] [] warn_slowpath_fmt+0x5c/0x80 [ 0.450130] [] note_page+0x5e1/0x780 [ 0.450132] [] ptdump_walk_pgd_level_core+0x307/0x450 [ 0.450133] [] ptdump_walk_pgd_level_checkwx+0x17/0x20 [ 0.450135] [] mark_rodata_ro+0xef/0x100 [ 0.450136] [] ? rest_init+0x90/0x90 [ 0.450138] [] kernel_init+0x1d/0xe0 [ 0.450139] [] ret_from_fork+0x3f/0x70 [ 0.450140] [] ? rest_init+0x90/0x90 [ 0.450141] ---[ end trace 60aa063fb3587a14 ]--- [ 0.454696] x86/mm: Checked W+X mappings: FAILED, 164057 W+X pages found. This is a new Clevo P651RA laptop (Skylake) booted via UEFI. A full dmesg for v4.4-8855-ga200dcb is attached as well as the contents of /sys/kernel/debug/kernel_page_tables. -- Kind regards, Peter Wu https://lekensteyn.nl