ci starts bisection 2025-06-21 23:23:31.679341171 +0000 UTC m=+82703.100153830 bisecting cause commit starting from 5d4809e25903ab8e74034c1f23c787fd26d52934 building syzkaller on d6cdfb8a765c64793bc63cf630e68fbdd0ee0974 ensuring issue is reproducible on original commit 5d4809e25903ab8e74034c1f23c787fd26d52934 testing commit 5d4809e25903ab8e74034c1f23c787fd26d52934 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 9d0cd9474bb2efc90ad1d627258ef93533ed020ccff0adfd4ae8aca0d177a582 all runs: crashed: general protection fault in pidfs_free_pid representative crash: general protection fault in pidfs_free_pid, types: [UNKNOWN] check whether we can drop unnecessary instrumentation disabling configs for [HANG LEAK UBSAN BUG KASAN LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 5d4809e25903ab8e74034c1f23c787fd26d52934 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 00a52e3406915a82d5eece3f26a5de66635a0652adc0471cf69cb451ceecd097 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] the bug reproduces without the instrumentation disabling configs for [LEAK UBSAN BUG KASAN LOCKDEP ATOMIC_SLEEP HANG], they are not needed kconfig minimization: base=4095 full=8372 leaves diff=2121 split chunks (needed=false): <2121> split chunk #0 of len 2121 into 5 parts testing without sub-chunk 1/5 disabling configs for [BUG KASAN LOCKDEP ATOMIC_SLEEP HANG LEAK UBSAN], they are not needed testing commit 5d4809e25903ab8e74034c1f23c787fd26d52934 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 24897aa54b60638f8187958bc3d8ab478a1099fc3d86cb3e2e4b625308fa863c all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [HANG LEAK UBSAN BUG KASAN LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 5d4809e25903ab8e74034c1f23c787fd26d52934 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 8249e5f83dbafcae06559e763268e9070318eb6474dbf1d33e683a0e25d5e2c2 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [LEAK UBSAN BUG KASAN LOCKDEP ATOMIC_SLEEP HANG], they are not needed testing commit 5d4809e25903ab8e74034c1f23c787fd26d52934 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 53108047b439d182e4b56d36e3fe24367cb571f29743e44873881744b8f295bc all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [HANG LEAK UBSAN BUG KASAN LOCKDEP ATOMIC_SLEEP], they are not needed testing commit 5d4809e25903ab8e74034c1f23c787fd26d52934 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 85c5ad05c4f3868a952cbc147deab37dd2f9ed64f2134817dd0f92cff3d6baff all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [KASAN LOCKDEP ATOMIC_SLEEP HANG LEAK UBSAN BUG], they are not needed testing commit 5d4809e25903ab8e74034c1f23c787fd26d52934 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 2c9c1a1b1302fee60ecc9b24b859c364755dc6e408a25df191ae7984ed6a0096 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] the chunk can be dropped disabling configs for [HANG LEAK UBSAN BUG KASAN LOCKDEP ATOMIC_SLEEP], they are not needed picked [v6.15 v6.14 v6.13 v6.11 v6.9 v6.7 v6.5 v6.3 v6.0 v5.17 v5.14 v5.11 v5.8 v5.5 v5.2 v4.20 v4.19] out of 38 release tags testing release v6.15 testing commit 0ff41df1cb268fc69e703a08a57ee14ae967d0ca gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: bb2a50ae353cd6e1b51661d6cde66dadf0beaf86aa65832a073729d43661dae4 all runs: OK false negative chance: 0.000 # git bisect start 5d4809e25903ab8e74034c1f23c787fd26d52934 0ff41df1cb268fc69e703a08a57ee14ae967d0ca Bisecting: 9201 revisions left to test after this (roughly 13 steps) [a4a45a9a72f3a9eaa17ec502d6e97c8eaa901825] fsdax: Remove unused trace events for dax insert mapping testing commit a4a45a9a72f3a9eaa17ec502d6e97c8eaa901825 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: b737d91980f4f88b2daaed111962d9f294126c34fd0b1bf34e8f78dd6e1e1a08 all runs: OK false negative chance: 0.000 # git bisect good a4a45a9a72f3a9eaa17ec502d6e97c8eaa901825 Bisecting: 4603 revisions left to test after this (roughly 12 steps) [d9864e7d151194b06c6cdbee8e69f0686238313a] Merge tag 'perf-urgent-2025-06-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit d9864e7d151194b06c6cdbee8e69f0686238313a gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 321acbc4e70d9c5e09cf49adedb91746d6e1d196db549a40601c2e769641d1c1 all runs: OK false negative chance: 0.000 # git bisect good d9864e7d151194b06c6cdbee8e69f0686238313a Bisecting: 2476 revisions left to test after this (roughly 11 steps) [fe60fa2473fa928a35ff9bc6a5bb387ba7d22c00] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git testing commit fe60fa2473fa928a35ff9bc6a5bb387ba7d22c00 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 458bd81e006faac722742b1d7e86062ae79dbd6f9e74697c8ced019882275cea all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] # git bisect bad fe60fa2473fa928a35ff9bc6a5bb387ba7d22c00 Bisecting: 1059 revisions left to test after this (roughly 10 steps) [2ffa34cee97738d5522150112c39d2c6bee090c3] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mediatek/linux.git testing commit 2ffa34cee97738d5522150112c39d2c6bee090c3 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 8b0ce0fbd83aadb6aeb6473c2b5ae613d6074bbcb2fa28141fcda444374bcccb all runs: OK false negative chance: 0.000 # git bisect good 2ffa34cee97738d5522150112c39d2c6bee090c3 Bisecting: 686 revisions left to test after this (roughly 9 steps) [fda1842990d65b0d239a33287574335c1e39a999] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git testing commit fda1842990d65b0d239a33287574335c1e39a999 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: fdca77155d80bcd470b49064e4b61fe99e77540abcccb5efe877c8863ef104cf all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] # git bisect bad fda1842990d65b0d239a33287574335c1e39a999 Bisecting: 163 revisions left to test after this (roughly 8 steps) [67b08453fbb5b41410ebe21893dde2dddd91493d] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git testing commit 67b08453fbb5b41410ebe21893dde2dddd91493d gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 317983173b709a06e6bdfc0536596f02d446dbfbd0f90457191af3315e52d774 all runs: OK false negative chance: 0.000 # git bisect good 67b08453fbb5b41410ebe21893dde2dddd91493d Bisecting: 75 revisions left to test after this (roughly 6 steps) [b71957b5e35d0a4ee25eabe37429c62afc6cf6b1] Merge branch 'vfs-6.17.pidfs' into vfs.all testing commit b71957b5e35d0a4ee25eabe37429c62afc6cf6b1 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 941174724cb157f1a7db0251cb49e85fb66382ca52c3f7c71e8e5197c390fa00 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] # git bisect bad b71957b5e35d0a4ee25eabe37429c62afc6cf6b1 Bisecting: 44 revisions left to test after this (roughly 6 steps) [3cff2aff718af6d38fb8c4fd2ab2e8f31e73293e] Merge branch 'vfs-6.17.coredump' into vfs.all testing commit 3cff2aff718af6d38fb8c4fd2ab2e8f31e73293e gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 6ad0437e1f5284f389225f820528c7d63fc08689cf5a3e3aa078aef68f2e3a96 all runs: OK false negative chance: 0.000 # git bisect good 3cff2aff718af6d38fb8c4fd2ab2e8f31e73293e Bisecting: 17 revisions left to test after this (roughly 5 steps) [97174a006434698e6ee13ed20ab6461d4dde8e98] Merge branch 'vfs-6.17.mmap_prepare' into vfs.all testing commit 97174a006434698e6ee13ed20ab6461d4dde8e98 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 616519656512067fafdbe246494a956b779c85bc83deec4ff5c986c874f69000 all runs: OK false negative chance: 0.000 # git bisect good 97174a006434698e6ee13ed20ab6461d4dde8e98 Bisecting: 8 revisions left to test after this (roughly 3 steps) [4f2075bfad6c23e19992f8b055aaf5d339ba2286] pidfs: remove pidfs_pid_valid() testing commit 4f2075bfad6c23e19992f8b055aaf5d339ba2286 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: c644a812abb6d2d4e71b2a1a1c8a28efd568658f5bf7c642f40c87f0e202548a all runs: OK false negative chance: 0.000 # git bisect good 4f2075bfad6c23e19992f8b055aaf5d339ba2286 Bisecting: 4 revisions left to test after this (roughly 2 steps) [7f4211bd1348a87834319a47ca2fe78ada143b46] selftests/pidfd: test extended attribute support testing commit 7f4211bd1348a87834319a47ca2fe78ada143b46 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: f3f5ccce8239f3be71cbcfe698966cf63ed7e68c3cf08cfa98401f15e1303b7f all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] # git bisect bad 7f4211bd1348a87834319a47ca2fe78ada143b46 Bisecting: 1 revision left to test after this (roughly 1 step) [faa963e22914937c1c5c5a7e8e8f43f4882a99d6] pidfs: make inodes mutable testing commit faa963e22914937c1c5c5a7e8e8f43f4882a99d6 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: d8315551d382a076b988830347a568c9b5bbf6ee35745eaecd76de21e343f415 all runs: OK false negative chance: 0.000 # git bisect good faa963e22914937c1c5c5a7e8e8f43f4882a99d6 Bisecting: 0 revisions left to test after this (roughly 0 steps) [fb0b3e2b2d7f213cb4fde623706f9ed6d748a373] pidfs: support xattrs on pidfds testing commit fb0b3e2b2d7f213cb4fde623706f9ed6d748a373 gcc compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 kernel signature: 3cffc5fb60fca023e86cd46af281ce070c7799f691f505b4c36b5369e24ce962 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid representative crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid, types: [UNKNOWN] # git bisect bad fb0b3e2b2d7f213cb4fde623706f9ed6d748a373 fb0b3e2b2d7f213cb4fde623706f9ed6d748a373 is the first bad commit commit fb0b3e2b2d7f213cb4fde623706f9ed6d748a373 Author: Christian Brauner Date: Wed Jun 18 22:53:46 2025 +0200 pidfs: support xattrs on pidfds Now that we have a way to persist information for pidfs dentries we can start supporting extended attributes on pidfds. This will allow userspace to attach meta information to tasks. One natural extension would be to introduce a custom pidfs.* extended attribute space and allow for the inheritance of extended attributes across fork() and exec(). The first simple scheme will allow privileged userspace to set trusted extended attributes on pidfs inodes. Link: https://lore.kernel.org/20250618-work-pidfs-persistent-v2-12-98f3456fd552@kernel.org Signed-off-by: Christian Brauner fs/pidfs.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 102 insertions(+), 4 deletions(-) accumulated error probability: 0.00 culprit signature: 3cffc5fb60fca023e86cd46af281ce070c7799f691f505b4c36b5369e24ce962 parent signature: d8315551d382a076b988830347a568c9b5bbf6ee35745eaecd76de21e343f415 revisions tested: 21, total time: 6h27m27.214364896s (build: 3h15m37.381309767s, test: 2h44m4.742305149s) first bad commit: fb0b3e2b2d7f213cb4fde623706f9ed6d748a373 pidfs: support xattrs on pidfds recipients (to): ["brauner@kernel.org" "linux-kernel@vger.kernel.org"] recipients (cc): ["brauner@kernel.org" "jack@suse.cz" "linux-fsdevel@vger.kernel.org" "viro@zeniv.linux.org.uk"] crash: BUG: unable to handle kernel NULL pointer dereference in pidfs_free_pid BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc1-syzkaller #0 PREEMPT(undef) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pidfs_free_pid+0x1c/0x60 fs/pidfs.c:162 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 56 53 48 8b 5f 70 48 c7 47 70 00 00 00 00 48 81 fb 00 f0 ff ff 77 33 <4c> 8b 33 4d 85 f6 74 1b 4c 89 f7 31 f6 e8 12 1e fe ff 49 81 fe 00 RSP: 0018:ffffc90000003ee8 EFLAGS: 00010207 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0df5d3885faa6b00 RDX: 8d1561c308730288 RSI: ffffffff8251e8eb RDI: ffff888101b68780 RBP: 0000000000000075 R08: 0000000000000000 R09: 00000000000000d3 R10: 0000000000000000 R11: ffffffff812d8ee0 R12: ffffffff81368571 R13: ffffffff82624880 R14: ffff88810339a000 R15: ffffffff812d8ee0 FS: 0000000000000000(0000) GS:ffff8882b4c3d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000102280000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: put_pid kernel/pid.c:103 [inline] delayed_put_pid+0x3c/0x70 kernel/pid.c:113 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0x3f0/0x8b0 kernel/rcu/tree.c:2832 handle_softirqs+0xf2/0x2f0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x48/0x110 kernel/softirq.c:680 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x92/0xb0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 93 0b 01 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 29 4f 0b 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff82603e90 EFLAGS: 000002c6 RAX: 0df5d3885faa6b00 RBX: 0000000000000000 RCX: 0df5d3885faa6b00 RDX: 00000000ffffa2df RSI: ffffffff82462126 RDI: ffffffff82520cb4 RBP: ffffffff82603ea8 R08: 0000000000080000 R09: 000000000000006f R10: 0000000000000000 R11: ffffffff8125aad0 R12: 0000000000000000 R13: ffffffff82624880 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x3d/0x70 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0xd7/0x240 kernel/sched/idle.c:325 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:423 rest_init+0xca/0xd0 init/main.c:744 start_kernel+0x2f5/0x310 init/main.c:1101 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0xfc/0x100 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:pidfs_free_pid+0x1c/0x60 fs/pidfs.c:162 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 56 53 48 8b 5f 70 48 c7 47 70 00 00 00 00 48 81 fb 00 f0 ff ff 77 33 <4c> 8b 33 4d 85 f6 74 1b 4c 89 f7 31 f6 e8 12 1e fe ff 49 81 fe 00 RSP: 0018:ffffc90000003ee8 EFLAGS: 00010207 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0df5d3885faa6b00 RDX: 8d1561c308730288 RSI: ffffffff8251e8eb RDI: ffff888101b68780 RBP: 0000000000000075 R08: 0000000000000000 R09: 00000000000000d3 R10: 0000000000000000 R11: ffffffff812d8ee0 R12: ffffffff81368571 R13: ffffffff82624880 R14: ffff88810339a000 R15: ffffffff812d8ee0 FS: 0000000000000000(0000) GS:ffff8882b4c3d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000102280000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 66 0f 1f 00 nopw (%rax) 12: 41 56 push %r14 14: 53 push %rbx 15: 48 8b 5f 70 mov 0x70(%rdi),%rbx 19: 48 c7 47 70 00 00 00 movq $0x0,0x70(%rdi) 20: 00 21: 48 81 fb 00 f0 ff ff cmp $0xfffffffffffff000,%rbx 28: 77 33 ja 0x5d * 2a: 4c 8b 33 mov (%rbx),%r14 <-- trapping instruction 2d: 4d 85 f6 test %r14,%r14 30: 74 1b je 0x4d 32: 4c 89 f7 mov %r14,%rdi 35: 31 f6 xor %esi,%esi 37: e8 12 1e fe ff call 0xfffe1e4e 3c: 49 rex.WB 3d: 81 .byte 0x81 3e: fe 00 incb (%rax)