On Thu, Sep 14, 2017 at 12:38 AM, Thomas Gleixner <[email protected]> wrote: > Hi! > > I've seen the following crash sporadically with commit 46c1e79fee: > > Have not seen that with 3882a734c19b, though I saw the PCID warnings on > that machine. > > I have no idea how to reproduce so bisecting is pretty much pointless. Any > idea what to do?
Does tools/testing/selftests/x86/sigreturn_64 reproduce it? > > Thanks, > > tglx > > > BUG: unable to handle kernel paging request at ffffffffffffffd8 > IP: __memmove+0x24/0x1a0 > PGD 1e17c0c067 P4D 1e17c0c067 PUD 1e17c0e067 PMD 0 > Oops: 0002 [#1] SMP > CPU: 43 PID: 1958 Comm: rsyslogd Tainted: G W 4.13.0+ #184 > task: ffff9eb5e8780080 task.stack: ffffb648a08cc000 > RIP: 0010:__memmove+0x24/0x1a0 > RSP: 0018:ffffb648a08cfef0 EFLAGS: 00252097 > RAX: ffffffffffffffd8 RBX: ffffffffffffff50 RCX: 0000000000000028 > RDX: 0000000000000028 RSI: ffffb648a08cffd8 RDI: ffffffffffffffd8 > RBP: ffffb648a08cff10 R08: ffffb648a08d0000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 > R13: ffffb648a08cff20 R14: 00007fffef2ed9a8 R15: 0000000000000000 > FS: 00007f05281eff80(0000) GS:ffff9eb5ff5c0000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffffffffffffffd8 CR3: 000000302857c002 CR4: 00000000001606e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > ? fixup_bad_iret+0x3c/0x60 > error_entry+0xb4/0xc0 > ? general_protection+0xc/0x30 > Code: 90 90 90 90 90 90 90 48 89 f8 48 83 fa 20 0f 82 03 01 00 00 48 39 fe 7d > 0f 49 89 f0 49 01 d0 49 39 f8 0f 8f 9f 00 00 00 48 89 d1 <f3> a4 c3 48 81 fa > a8 02 00 00 72 05 40 38 fe 74 3b 48 83 ea 20 > RIP: __memmove+0x24/0x1a0 RSP: ffffb648a08cfef0 > CR2: ffffffffffffffd8 Ugh, weird. It kind of looks like current->thread.sp0 == NULL. I have a patch series that changes a bunch of that code in my git tree, but that's definitely not in Linus' tree.
