- Validate any stack addresses read from against td_kstack before
reading. If an unwind operation would attempt to read outside the
bounds of td_kstack, abort the unwind instead.
- For stack_save_td(), don't use the PC and SP from the current
thread, instead read the PC and SP from pcb_context[].
- For stack_save(), use the current PC and SP of the current thread,
not the values from pcb_regs (the horribly named td_frame of the
outermost trapframe). The result was that stack_trace() never
logged _any_ kernel frames but only the frame from the saved
userspace registers on entry from the kernel.
- Inline the one use of stack_register_fetch().
- Add a VALID_PC() helper macro and simplify types to remove
excessive casts in stack_capture().
- Fix stack_capture() to work on compilers written in this century.
Don't treat function epilogues as function prologues by skipping
additions to SP when searching for a function start.
- Add some comments to stack_capture() and fix some style bugs.
Reviewed by: arichardson
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27358
f2dceb474b