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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/hacking.md | 22 |
1 files changed, 10 insertions, 12 deletions
diff --git a/doc/hacking.md b/doc/hacking.md index 99404064..12672fd1 100644 --- a/doc/hacking.md +++ b/doc/hacking.md @@ -212,18 +212,16 @@ Use `config.color.toml` and `my-test-case.color.expected` to preserve colors. ### Sandbox violations -First, note that a nil deref can also trigger a sandbox violation. Read -the stack trace to make sure you aren't dealing with that. - -Then, figure out if it's happening in a CGI process or a buffer -process. If your buffer was swapped out for the console, it's likely the -latter; otherwise, the former. - -Now change the appropriate sandbox handler from `SCMP_ACT_TRAP` to -`SCMP_ACT_KILL_PROCESS`. Run `strace -f ./cha -o start.console-buffer [...] 2>a`, -trigger the crash, then search for "killed by SIGSYS" in `a`. Copy the -logged PID, then search backwards once; you should now see the syscall -that got your process killed. +You got a syscall number (assuming you're on Linux); look it up in the +Linux syscall table for your architecture. + +To get more context on what happened, you can run +`strace -f ./cha -o start.console-buffer [...] 2>a`, trigger the crash, +then search for the last occurrence of "--- SIGSYS". Then search +backwards on the PID to see the last syscalls. + +(Incidentally, strace also shows the syscall name, so it may be easier +to check like that than looking it up in the syscall table.) ## Resources |