Problem:
- Many constructors are defined as `{}` rather than using the ` =
default` compiler-provided constructor.
- Some types provide an implicit conversion operator from `nullptr_t`
instead of requiring the caller to default construct. This violates
the C++ Core Guidelines suggestion to declare single-argument
constructors explicit
(https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c46-by-default-declare-single-argument-constructors-explicit).
Solution:
- Change default constructors to use the compiler-provided default
constructor.
- Remove implicit conversion operators from `nullptr_t` and change
usage to enforce type consistency without conversion.
Let's adapt this class a bit better to how it's actually being used.
Instead of having valid/invalid states and storing an error in case
it's invalid, a MappedFile is now always valid, and the factory
function that creates it will return an OSError if mapping fails.
DebugSession now makes the loader stop after loading the libraries,
and parses the loaded libraries of the program before continuing its
execution.
DebugSession now also supports inserting a breakpoint at a given symbol
or source position.
Additionally, DebugInfo now takes the base address of its object into
consideration.
This commit gets rid of ELF::Loader entirely since its very ambiguous
purpose was actually to load executables for the kernel, and that is
now handled by the kernel itself.
This patch includes some drive-by cleanup in LibDebug and CrashDaemon
enabled by the fact that we no longer need to keep the ref-counted
ELF::Loader around.
Breakpoints need to be disabled before we detach from the debugee.
I noticed this while looking into the fact that if you continue
executing a program in sdb (/bin/ls) where you had previously
set a breakpoint, it would crash on sdb exit once the debugee died
with an assert on HashMap destruction where we were iterating
while clearing is set. This change also happens to fix this assert.
After hitting a breakpoint, we single step the program to execute the
instruction we breaked on and re-enable the breakpoint.
We also single step the program when the user of LibDebug returned a
DebugDecision::SingleStep.
Previously, if we hit a breakpoint and then were asked to to a
DebugDecision::SingleStep, we would single step twice.
This bug can actually crash programs, because it might cause us to
skip over a patched INT3 instruction in the second single-step.
Interestingely enough, this bug manifested as functrace crashing
certain programs: after hitting a breakpoint on a CALL instruction,
functrace single steps the program to see where the CALL jumps to
(yes, this can be optimized :D). functrace crashed when a CALL
instruction jumps to another CALL, because it inserts breakpoints on CALL
instructions, and so the INT3 in the 2nd CALL was skipped over, and we
executed garbage :).
This commit fixes this by making sure not to single-step twice.
When the user of the DebugSession uses this decision, the debugged
program will be continued until it is either stopped by a singal (e.g
as a reuslt of a breakpoint), or enters a syscall.
functrace traces the function calls a program makes.
It's like strace, but for userspace.
It works by using Debugging functionality to insert breakpoints
at call&ret instructions.
2020-04-16 11:17:33 +02:00
Renamed from Applications/Debugger/DebugSession.cpp (Browse further)
