Hi Kees, I got the below dmesg and the first bad commit is git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/kaslr commit aec58bafaf89279522c44ec8ca9211eabb2b6976 Author: Kees Cook AuthorDate: Tue Oct 15 23:43:14 2013 -0700 Commit: Ingo Molnar CommitDate: Fri Oct 18 08:45:09 2013 +0200 x86/relocs: Add percpu fixup for GNU ld 2.23 The GNU linker tries to put __per_cpu_load into the percpu area, resulting in a lack of its relocation. Force this symbol to be relocated. Seen starting with GNU ld 2.23 and later. Reported-by: Ingo Molnar Signed-off-by: Kees Cook Cc: Michael Davidson Cc: Cong Ding Link: http://lkml.kernel.org/r/20131016064314.GA2739@www.outflux.net Signed-off-by: Ingo Molnar =================================================== PARENT COMMIT NOT CLEAN. LOOK OUT FOR WRONG BISECT! =================================================== +-------------------------------------------------------------+--------------+--------------+ | | 6e6a4932b0f5 | ee8502c1320d | +-------------------------------------------------------------+--------------+--------------+ | boot_successes | 2 | 3 | | boot_failures | 90 | 16 | | BUG:kernel_boot_hang | 90 | 1 | | WARNING:CPU:PID:at_arch/x86/mm/ioremap.c:__ioremap_caller() | 0 | 13 | | kernel_BUG_at_drivers/mtd/maps/map_funcs.c | 0 | 13 | | invalid_opcode:PREEMPT_SMP | 0 | 13 | | RIP:simple_map_init | 0 | 13 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 13 | | BUG:kernel_boot_crashed | 0 | 2 | +-------------------------------------------------------------+--------------+--------------+ [772816.202632] Trying default address 0x9400000 [772816.204786] SC520 CDP flash device: 0x800000 at 0x8400000 [772816.207465] ------------[ cut here ]------------ [772816.209801] WARNING: CPU: 0 PID: 1 at arch/x86/mm/ioremap.c:102 __ioremap_caller+0x188/0x47b() [772816.215033] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc8-next-20140117-10527-gee8502c #1 [772816.219226] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [772816.221952] 0000000000000000 ffff880000261d98 ffffffff86ace803 0000000000000000 [772816.225852] ffff880000261dd0 ffffffff85890af2 ffffffff8583ee3a 0000000000000010 [772816.229713] 0000000008400000 0000000000008400 0000000008c00000 ffff880000261de0 [772816.233566] Call Trace: [772816.234854] [] dump_stack+0x94/0xf1 [772816.237503] [] warn_slowpath_common+0x93/0xc1 [772816.240452] [] ? __ioremap_caller+0x188/0x47b [772816.243362] [] warn_slowpath_null+0x23/0x2c [772816.246050] [] __ioremap_caller+0x188/0x47b [772816.248937] [] ? init_sc520cdp+0x13d/0x333 [772816.251748] [] ? printk+0x56/0x5f [772816.254062] [] ioremap_nocache+0x20/0x29 [772816.256751] [] init_sc520cdp+0x13d/0x333 [772816.259451] [] ? init_sbc_gxx+0x16d/0x16d [772816.262099] [] do_one_initcall+0xca/0x1be [772816.264837] [] ? parameq+0x24/0x2d [772816.267349] [] ? parse_args+0x268/0x3ac [772816.269904] [] kernel_init_freeable+0x1b5/0x2c2 [772816.272890] [] ? do_early_param+0xd7/0xd7 [772816.275339] [] ? rest_init+0x124/0x124 [772816.277843] [] kernel_init+0x10/0x175 [772816.280417] [] ret_from_fork+0x7c/0xb0 [772816.283077] [] ? rest_init+0x124/0x124 [772816.285598] ---[ end trace 3387ed51c8e66d88 ]--- [772816.291966] Failed to ioremap_nocache git bisect start e502f4ce9070fef25d14a8159403e45a3982e913 v3.12 -- git bisect good 22056614ee39ef43670814d2000f810901768277 # 20:34 21+ 0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux git bisect good 2e67c56248b776c0a546925c796cdb167ee4d7a0 # 20:52 21+ 0 Merge branch 'akpm' (incoming from Andrew) git bisect good b12325ff6ef054732eb0cb18c5420350fa0721d4 # 21:05 21+ 0 Merge remote-tracking branch 'swiotlb/linux-next' git bisect good 54ea1a48d90affdbc1501cfa59f57e5411d0b16d # 21:15 21+ 0 Merge remote-tracking branch 'trivial/for-next' git bisect bad b0416e0034cef13cec26d2f01e90d55611bba7da # 21:23 0- 8 Merge remote-tracking branch 'chrome-platform/for-next' git bisect bad baf310ca0c9d2c65ac968e9d75ffbd9ea92d1a51 # 21:28 0- 1 Merge remote-tracking branch 'ftrace/for-next' git bisect good 97ae9c3495474b422373d6e93270929981caf4ff # 21:45 21+ 0 Merge remote-tracking branch 'spi/for-next' git bisect bad f0c2b327e8ef8ceb3889c357a74d63ce02ab8b0c # 21:50 0- 1 Merge remote-tracking branch 'clockevents/clockevents/next' git bisect bad e52ea51f9fa767b1dc4f737486e1791601c57c2e # 21:52 0- 6 Merge remote-tracking branch 'tip/auto-latest' git bisect good 1341f3e4c0276aae3de6d902c9202265d89fe438 # 22:06 21+ 0 Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core git bisect good c3e32e1de82315e3557e0834265f051594ac82de # 22:22 21+ 0 manual merge of sched/core git bisect good 4a4ac149163e8370742ab8e225b0a23feb362442 # 22:33 21+ 1 Merge branch 'x86/cpufeature' git bisect bad bf73d38250020e92b1095b567fe253d005e54cc1 # 22:39 1- 4 Merge branch 'x86/kaslr' git bisect good 61d066977583803d333f1e7266b8ba772162dda4 # 22:54 23+ 1 Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efi git bisect good ef0b8b9a521c65201bfca9747ee1bf374296133c # 23:08 23+ 0 Merge tag 'v3.13-rc7' into x86/efi-kexec to resolve conflicts git bisect good 6145cfe394a7f138f6b64491c5663f97dba12450 # 23:32 23+ 23 x86, kaslr: Raise the maximum virtual address to -1 GiB on x86_64 git bisect bad e8236c4d9338d52d0f2fcecc0b792ac0542e4ee9 # 23:34 0- 1 x86, kaslr: Add a circular multiply for better bit diffusion git bisect bad aec58bafaf89279522c44ec8ca9211eabb2b6976 # 23:35 0- 2 x86/relocs: Add percpu fixup for GNU ld 2.23 git bisect good 6e6a4932b0f569b1a5bb4fcbf5dde1b1a42f01bb # 23:49 23+ 23 x86, boot: Rename get_flags() and check_flags() to *_cpuflags() # first bad commit: [aec58bafaf89279522c44ec8ca9211eabb2b6976] x86/relocs: Add percpu fixup for GNU ld 2.23 git bisect good 6e6a4932b0f569b1a5bb4fcbf5dde1b1a42f01bb # 00:12 69+ 90 x86, boot: Rename get_flags() and check_flags() to *_cpuflags() git bisect bad ee8502c1320d626417b98a94e0367e9a1e269a5a # 00:12 0- 16 Add linux-next specific files for 20140117 git bisect good bb3a32a31f86badc0ed5ab666106f73f838d0245 # 00:39 69+ 69 Revert "x86/relocs: Add percpu fixup for GNU ld 2.23" git bisect good 7d0d46da750a252371cb747b48ddda27d1047881 # 00:58 69+ 3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net git bisect bad ee8502c1320d626417b98a94e0367e9a1e269a5a # 00:58 0- 16 Add linux-next specific files for 20140117 Thanks, Fengguang