[Bug]: Bad page map in process conky causes crash

[yongjizhao]

What happened?

No response

Version

conky 1.12.2

Which OS/distro are you seeing the problem on?

Ubuntu

Stack trace

audit[1927]: ANOM_ABEND auid=1001 uid=1001 gid=1001 ses=1 subj=unconfined pid=1927 comm="conky" exe="/usr/bin/conky" sig=11 res=1
audit[1927]: ANOM_ABEND auid=1001 uid=1001 gid=1001 ses=1 subj=unconfined pid=1927 comm="conky" exe="/usr/bin/conky" sig=11 res=1
kernel: show_signal_msg: 17 callbacks suppressed
kernel: conky[1948]: segfault at 7f3054277ae0 ip 00007f3054277ae0 sp 00007f304e057908 error 15 in libstdc++.so.6.0.30[7f30541c4000+111000]
kernel: Code: 48 89 c1 48 89 f2 48 8d 3d 45 04 06 00 31 c0 48 8d 35 24 04 06 00 e8 3f 0f f5 ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <
kernel: conky[1963]: segfault at 7f3054277ae0 ip 00007f3054277ae0 sp 00007f3047049908 error 15
kernel: Code: 48 89 c1 48 89 f2 48 8d 3d 45 04 06 00 31 c0 48 8d 35 24 04 06 00 e8 3f 0f f5 ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <
kernel: __swap_info_get: Bad swap file entry 28037fffffffffff
kernel: BUG: Bad page map in process conky  pte:5100000000000000 pmd:10b6b3067
kernel: addr:00007f305420b000 vm_flags:08000075 anon_vma:0000000000000000 mapping:ffff9e8183b1abe8 index:e1
kernel: file:libstdc++.so.6.0.30 fault:filemap_fault mmap:ext4_file_mmap readpage:ext4_readpage
kernel: CPU: 1 PID: 1967 Comm: conky Not tainted 5.15.0-91-generic #101-Ubuntu

Relevant log output

No response

[brndnmtthws]

It would be very helpful if you could obtain a stack trace.

Instructions for getting debug symbols on Ubuntu are available here: https://wiki.ubuntu.com/Debug%20Symbol%20Packages

And there are instructions here on how to obtain a stack trace with gdb (should work with lldb too, if you prefer LLVM): https://askubuntu.com/a/1349048

[Caellian]

Given that the kernel spits out errors with regards to mmap, and that we use mmap from a single place in conky here. I'm assuming that call is failing.

According to wayland docs:

From version 7 onwards, the fd must be mapped with MAP_PRIVATE by the recipient, as MAP_SHARED may fail.

We don't need a MAP_SHARED mmap.

[Caellian]

Assuming the PR fixes the issue. Please provide more details to have this issue reopened.

[Caellian]

From version 7 onwards, the fd must be mapped with MAP_PRIVATE by the recipient, as MAP_SHARED may fail.

This comes from wl_keyboard::keymap, not sure how I got it mixed into wl_shm::create_pool. Maybe opened a wrong tab?! 🤷‍♂️

This issue is reopened by #2104.

@yongjizhao can you specify your WM and whether you're using wayland? Does this issue still occur on latest main branch?