Hi Joe, Here is one more bisect result for your reference. commit eea0e9cbb9e65cd553d302a4aefd4c7b70d9fd90 Author: Joe Mario Date: Wed Oct 23 15:06:53 2013 +0200 kbuild: Increase kallsyms max symbol length [AK: This seems like a ticking time bomb even without LTO, so should be merged now. It causes very weird problems. Thanks to Joe for tracking them down.] With the added postfixes that LTO adds for local symbols, the longest name in the kernel overflows the namebuf[KSYM_NAME_LEN] array by two bytes. That name is: __pci_fixup_resumePCI_VENDOR_ID_SERVERWORKSPCI_DEVICE_ID_SERVERWORKS_HT1000SBquirk_disable_broadcom_boot_interrupt.1488004.672802 Double the max symbol name length. v2: Use 255 (Joe Perches) Signed-off-by: Andi Kleen Signed-off-by: Michal Marek =================================================== PARENT COMMIT NOT CLEAN. LOOK OUT FOR WRONG BISECT! =================================================== +-----------------------------------------------------------+--------------+--------------+ | | 80970472179a | 9aab69def5d7 | +-----------------------------------------------------------+--------------+--------------+ | good_boots | 58 | | | has_kernel_error_warning | 2 | 19 | | BUG:kernel_boot_hang | 1 | | | BUG:Bad_page_map_in_process_killall5_pte:pmd | 1 | | | BUG:unable_to_handle_kernel_NULL_pointer_dereference_at | 0 | 19 | | Oops:PREEMPT_SMP | 0 | 19 | | Kernel_panic-not_syncing:Attempted_to_kill_init_exitcode= | 0 | 19 | +-----------------------------------------------------------+--------------+--------------+ [ 2.754985] NatSemi SCx200 Driver [ 2.755083] cryptomgr_test (23) used greatest stack depth: 7100 bytes left [ 2.760079] Initializing RT-Tester: OK [ 2.790487] BUG: unable to handle kernel NULL pointer dereference at 00000008 [ 2.791013] IP: [] restore_sigcontext+0x12e/0x370 [ 2.791013] *pde = 00000000 [ 2.791013] Oops: 0002 [#1] PREEMPT SMP [ 2.791013] Modules linked in: [ 2.791013] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.12.0-01287-g9aab69d #1176 [ 2.791013] task: b0048000 ti: b0044000 task.ti: b0044000 [ 2.791013] EIP: 0060:[] EFLAGS: 00010286 CPU: 0 [ 2.791013] EIP is at restore_sigcontext+0x12e/0x370 [ 2.791013] EAX: 00000000 EBX: b1d04f90 ECX: 0000000d EDX: 00000001 [ 2.791013] ESI: 00000006 EDI: 000000c4 EBP: b0045f9c ESP: b0045f80 [ 2.791013] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [ 2.791013] CR0: 8005003b CR2: 00000008 CR3: 01e62000 CR4: 00000690 [ 2.791013] Stack: [ 2.791013] 000000c4 00000006 00000006 b1c91706 00000000 bdbbb940 b1bb1e20 b0045fac [ 2.791013] b18491b9 bdbbb940 b0047f88 b0044000 b1876fbb b18491a0 00000000 00000000 [ 2.791013] 00000000 00000000 00000000 00000000 0000007b 0000007b 000000d8 00000000 [ 2.791013] Call Trace: [ 2.791013] [] ? do_early_param+0x12b/0x12b [ 2.791013] [] kernel_init+0x19/0x280 [ 2.791013] [] ret_from_kernel_thread+0x1b/0x30 [ 2.791013] [] ? rest_init+0x280/0x280 [ 2.791013] Code: 6e e6 b1 00 89 58 3c 8b 5a 20 83 05 60 6e e6 b1 01 83 15 64 6e e6 b1 00 89 18 8b 5a 24 83 05 68 6e e6 b1 01 83 15 6c 6e e6 b1 00 <89> 58 08 8b 5a 28 83 05 70 6e e6 b1 01 83 15 74 6e e6 b1 00 89 [ 2.791013] EIP: [] restore_sigcontext+0x12e/0x370 SS:ESP 0068:b0045f80 [ 2.791013] CR2: 0000000000000008 [ 2.815207] ---[ end trace 7a5fb510918bc4ea ]--- [ 2.815952] swapper/0 (1) used greatest stack depth: 5712 bytes left git bisect start 9aab69def5d79c04a6dbf6d5646043193e673bc5 5e01dc7b26d9f24f39abace5da98ccbd6a5ceb52 -- git bisect good a89b2a0fcc3c857c5b8b6b54798aaba5d1aac28c # 11:49 20+ 0 Merge tag 'usb-for-v3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into connectivity-ti-linux-3.12.y git bisect good 8ffb929098a56939ac71509302eeab5b207bf262 # 12:14 20+ 3 Bluetooth: Remove parent socket usage from l2cap_core.c git bisect good 90570c54a58ad4543e9ba418ff20424659d5f4e3 # 12:43 20+ 0 phy: kconfig: add depends on "USB_SUPPORT" to OMAP_USB2 and TWL4030_USB git bisect good 4074afe30e0228d9dc299df1d73a511335bb4c5b # 13:18 20+ 2 ARM: OMAP2+: hwmod_7xx: Add data structures for McASP3 git bisect good 9fbe8e5b9724e0034618bd512df9eda4694e77d5 # 13:36 20+ 1 Merge branch 'kbuild/kconfig' into kbuild/for-next git bisect good 7def68012f470495d1aaad9bd51fcd87c6111645 # 14:24 20+ 3 Bluetooth: ath3k: Add support for a new AR3012 device git bisect bad 3657319957a9e1500bea4694968f97dd596f7b53 # 14:30 0- 1 Merge branch 'kbuild/kbuild' into kbuild/for-next git bisect bad 37d1c5fc2dd80db8c084e5c3d324cb92dd6e5a94 # 14:34 0- 1 Merge branches 'kbuild/kbuild' and 'kbuild/misc' into kbuild/for-next git bisect bad 21cf6e584ce35b79374581e6344dd7c74f8b4a2b # 14:36 0- 1 kbuild, bloat-o-meter: fix static detection git bisect bad f3462aa952cfc8f4b095103cb9b3d306dd216558 # 14:39 0- 1 Kbuild: Handle longer symbols in kallsyms.c git bisect bad eea0e9cbb9e65cd553d302a4aefd4c7b70d9fd90 # 14:40 0- 1 kbuild: Increase kallsyms max symbol length git bisect good 80970472179a45609c0b11b80619bc8c32b15f77 # 15:08 60+ 2 Makefile: enable -Werror=implicit-int and -Werror=strict-prototypes by default git bisect bad 9aab69def5d79c04a6dbf6d5646043193e673bc5 # 15:08 0- 19 Merge 'omap-audio/peter/ti/ti-linux-3.12.y-o5_dra7_mcasp' into devel-inn-i386-201311081714 git bisect good 9388496f314901ac8ca155e8558d5dc5dbe39d0d # 15:33 60+ 0 Revert "kbuild: Increase kallsyms max symbol length" git bisect good 6c86ae2928f9e4cbf0d5844f5fcfd549e3450b8c # 15:41 60+ 0 Merge tag 'ftrace-urgent-3.12-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Thanks, Fengguang