* get_one_instruction: clear "cont" cache on mem/reg changed
Fixes#1818.
Note that this makes a substantial change: it changes all caches that
are refreshed on `gdb.ContinueEvent` to also be cleared on memory/regs
changed.
This change is needed so that the `get_one_instruction` function which
uses this cache will get its cache cleared when user invokes a command
that changes memory or registers.
While this may sound as too big change: we are changing the whole "cont"
cache to be cleared on two additional events, this should not be an
issue. This is because:
1. We should notice it if we start clearing an important cache too often
2. The "cont" cache is currently only used by the `get_one_instruction`
at this moment.
The 2) also creates a question: when should one use "cont" vs "start"
caches? It is not so clear to me right now.
* Add test for issue #1818
* Clear caches on MemoryChanged events from gdblib.write
Regarding the last part:
Interestingly implementing tests here uncovered another bug: the gdblib.memory.write(..) or rather the gdb.selected_inferior().write_memory(...) API used there does not trigger a gdb.MemoryChanged event. As a result, we never cleared certain caches that should have been cleared when the user used that API.
I have added two tests here, one changes the instructions at $RIP to nops via gdblib.memory.write(..) and another via executing the patch $rip nop;nop;nop;nop;nop command. As a result, we test both scenarios: 1) when we depend on memory changed event being fired via GDB to clear caches; and 2) when we depend on gdblib.memory.write(..) to clear the caches.
This PR also makes a fix to the gdblib.memory.write(..) to actually clear caches that depend on (or rather: are hooked to in order to be cleared) memory changed events.
* Fix glibc-fastbin-bug option of find_fake_fast
Using the find_fake_fast option --glibc-fastbin-bug always resulted in an error, at least on 64-bit platforms.
This was because the option caused only 4 bytes to be read for the size, but then that gets passed to unpack() which expects 8 bytes.
Closes#1773
* Address review comment
* Update arch.py
* Update pwndbg/commands/heap.py
* Fix lint
* Update arch.py
* Update arch.py
---------
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>
This commit adds a command that traverses the linked list beginning at a given
element, dumping its contents and the contents of all the elements that come
after it in the list. Traversal is configurable and can handle multiple types
of chains.
This commit adds the `break-if-taken` and `break-if-not-taken` commands,
which attach breakpoints to branch instructions that will stop the
inferior if said branch is taken or is not taken, respectively. It adds
an extra class, `pwndbg.gdblib.bpoint.Breakpoint`, which clears caches
before calling `stop()`, allowing for the use of register values inside
that function in breakpoint classes that derive from it. Additionally,
checking of whether the conditions for a branch to be taken have been
fulfilled is done through `DisassemblyAssistant.condition()`.
* Add `stepuntilasm` command
This commit adds a `stepuntilasm` command that, given a mnemonic and,
optionally, a set of operands, will step until a instruction that
matches both is found. Matching is string-based, as the user will likely
want to spell out the asm directive they want as text, and interpreting
assembly language conventions for all of the platforms pwndbg supports
is probably outside the scope of this change.
* next.py: small code cleanup
* next.py: fix bug introduced in previous commit
op.str -> op_str
* Update next.py
* Update next.py
* Update next.py
---------
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>
* Only run arch for testing
* Remove outdated arch repo
* Actually build the docker image
* Do not include site packages in sys.path
* Ignore `.relr.dyn` section; skip lines w/o spaces
Newer binaries can contain a `.relr.dyn` section to compress `R_X86_64_RELATIVE` relocation entries.
These binaries can be found for example on archlinux but also on Debian 12 for example.
`readelf` prints the content of the section similarly to this:
```
Relocation section '.relr.dyn' at offset 0x25220 contains 35 entries:
1198 offsets
00000000001ce8d0
00000000001ce8e0
```
Compared to `00000000001d2000 0000000000000025 R_X86_64_IRELATIVE 9f330` for
`.rela.plt`.
Pwndbg now chokes on the new format because it expects a space seperator where there is none.
It might be, that this is actually an upstream problem with binutils, because llvm-readelf prints this:
```
Relocation section '.relr.dyn' at offset 0x25220 contains 1198 entries:
Offset Info Type Symbol's Value Symbol's Name
00000000001ce8d0 0000000000000008 R_X86_64_RELATIVE
00000000001ce8e0 0000000000000008 R_X86_64_RELATIVE
```
Nevertheless, we aren't actually interested in `R_X86_64_RELATIVE` relocations so I guess it's fine to
just skip all lines that contain no spaces at all.
`.relr.dyn` can only containt `R_X86_64_RELATIVE` relocations as far as I understand
https://maskray.me/blog/2021-10-30-relative-relocations-and-relr
* Accept Full RELRO in test
Archlinux has libc and ld with Full RELRO.
We now just accept Partial and Full RELRO.
* Do not copy binaries from host to docker
The `Dockerfile` copies the whole pwndbg folder to the image.
If we have built binaries on the host before, these binaries will contain references to
the host system and *copied* to the image.
If we now run `context code` (inside docker) to have a look at the source code this will
fail, because we will try to refer to a path on the host system.
* Do not use loop index after loop
Do not use loop index after the loop. The tests assumed that the loop in line 186
would run at least once, thereby *resetting* `i` to zero. If we never enter the
loop, `i` will *continue* to have the value it had at the end of line 172.
This will cause the test to fail in mysterious ways because `i` is now not reset
to zero but still has the value `31` for example.
The solution is to never use `i` outside of a loop.
* Re-enable archlinux and temporarily disabled ones
* Fix coverage combine toml issue
This commit should fix this issue:
```
Run coverage combine
coverage combine
coverage xml
shell: /usr/bin/bash -e {0}
Can't read 'pyproject.toml' without TOML support. Install with [toml] extra
Error: Process completed with exit code 1.
```
* setup.sh: cleanup the --user flag since we use venv now
Cleans up the --user flag from setup.sh since it is unused after we changed setup.sh to install Python dependencies in a virtual environment
* Remove --user flag from CI workflows
* Fix codecov problem
We need to run the python `coverage` library to collect coverage.
However, gdb was failing to find it.
Recently, pwndbg moved to using venvs. When pwndbg is initialized
it setups the venv "manually", that is, no "source .venv/bin/activate"
is needed. When we run gdb tests, we pass the `gdbinit.py` of pwndbg as a
command to gdb to be executed like this:
`gdb --silent --nx --nh -ex 'py import coverage;coverage.process_startup()' --command PATH_TO_gdbinit.py`
The problem is that *order* matters. This means that *first* coverage
is imported (by `-ex py ...`) and only *then* the init script is executed.
When `coverage` is first imported, it's library search path only looks
in system libraries of python, and not the venv that gdbinit.py would load.
So we would try to import an old version of coverage and fail.
One solution would be to move around the commands, but this would be an
ugly hack IMHO. **Instead**, we should just tell gdb that this is an **init**
command that has to be executed before other commands.
Previously, the order did not matter. All of pwndbg's dependencies were
installed directly as system libraries to python. So the library search path
was the same before and after loading `gdbinit.py`.
---------
Co-authored-by: disconnect3d <dominik.b.czarnota@gmail.com>
Co-authored-by: intrigus <abc123zeus@live.de>
* Refactor the `got` command to support more use cases
- Create some function to parse the information of loaded shared object libraries from `info sharedlibrary`
- Make got command can show the entries of other libraries loaded in memory
- Make got command can show more various relocations to support not only the `JUMP_SLOT` type relocation but also supports `IRELATIVE` and `GLOB_DAT` type relocation.
* Update tests for the `got` command
* Update pwndbg/commands/got.py
* Update pwndbg/commands/got.py
* Update pwndbg/commands/got.py
* Update pwndbg/commands/got.py
* Update pwndbg/commands/got.py
* Update pwndbg/commands/got.py
* Update pwndbg/commands/got.py
* Update pwndbg/commands/got.py
* Update the comment
https://github.com/pwndbg/pwndbg/pull/1771#discussion_r1251054080
* Update the tests
* Add some hints for the qemu users
---------
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>
* Fix and test ctx disasm when disassembly-flavor changes
* New lib/cache.py: make caching great again
This commit fixes bugs with old caching (memoize.py) and makes it more
readable.
See also https://github.com/pwndbg/pwndbg/issues/1453
* Update pwndbg/lib/cache.py
Co-authored-by: Gulshan Singh <gsingh2011@gmail.com>
* lib.cache: address PR comments and add debug mode
* Fix lint
* Remove leftover memoize usages
* Add cache benchmark
* fix lint
---------
Co-authored-by: Gulshan Singh <gsingh2011@gmail.com>
* feature: Add `killthreads` command (closes#1580)
This command allows the user to quickly kill multiple threads by
specyfying their ids as arguments to this command. It also supports
the `--all` flag, which will kill overy thread except the currently
selected one. This is useful for use with the `checkpoint` command.
The killing is done by calling `pthread_exit(0)`.
* fix: try fixing building test binaries by enabling -lpthread
* fix: remove error message check when calling pthread_exit
Removed the message check, because the error messages difffer between
versions of GDB.
* fix: Improve UX of the killthreads command
Add an extended description of the command, some validation on the thread IDs
and suppress GDB output.
* fix: lint
* fix: put the multiline help text in the correct place
* tests: fix test failing due to a race condition when running in parrallel to other tests
Replaced asserts with loops which wait for a cundition to be met, so that the tests doesn't fail due to scheduling issues.
* tests: add more fixes for race conditions in test_killthreads
* fix: lint
* Update pwndbg/commands/killthreads.py
* tests: Wait for exactly three threads
---------
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>
* Changing the arguments to vis_heap_chunks to be clearer
1. --native to --beyond_top
2. --display_all to --no_truncate
* Add print all chunks to vis_heap_chunks
* Preventing the use of the all_chunks argument together with the count argument in vis_heap_chunks
* Use linting for heap.py
* Fix test_vis_heap_chunks.py
According to cdd71a1d82 --display_all/-d moved to --no_truncate/-n
---------
Co-authored-by: Nerya Zadkani <nerya@tokagroup.com>
This commit adds a fix and tests for #1600 and #752.
* https://github.com/pwndbg/pwndbg/issues/1600
* https://github.com/pwndbg/pwndbg/issues/752
Generally, for an example like this:
```cpp
struct A {
void foo(int, int) { };
};
int main() {
A a;
a.foo(1, 1);
}
```
The output for `info symbol <address of A::foo>` returns:
```
'A::foo(int, int) [clone.isra.0] + 3 in section .text of /root/pwndbg/tests/gdb-tests/tests/binaries/a.out\n'
```
We then used this code to parse this:
```py
# Expected format looks like this:
# main in section .text of /bin/bash
# main + 3 in section .text of /bin/bash
# system + 1 in section .text of /lib/x86_64-linux-gnu/libc.so.6
# No symbol matches system-1.
a, b, c, _ = result.split(maxsplit=3)
if b == "+":
return "%s+%s" % (a, c)
if b == "in":
return a
return ""
```
The `result.split(maxsplit=3)` here splitted the string to:
```py
['A::foo(int,',
'int)',
'[clone.isra.0] + 3 in section .text of /root/pwndbg/tests/gdb-tests/tests/binaries/a.out\n']
```
And since `b` was not `"+"` or `"in"` we eventually returned an empty
string instead of the `A::foo(int, int)` which would be expected here.
* Fix the bug when using LD_PRELOAD to load libc
The heap heuristics will try to find `libc.so.6` in the output of `info sharedlibrary`, but if we load libc with `LD_PRELOAD`, the filename of the libc might not be `libc.so.6`.
* Add test for `glibc.get_libc_filename_from_info_sharedlibrary`
* Refactor `pwndbg.glibc`
- Add type hints
- Use `info sharedlibrary` to find libc
- Update the regex of libc filename
- Rename `get_data_address()` to `get_data_section_address()`
* Add a function to dump libc ELF file's .data section
* Use the new methods to find `main_arena` and `mp_`
With ELF of libc, we can use the default value of `main_arena` and `mp_` to find their address
* Drop some unreliable methods for the heap heuristics
* Update the tests for the heap heuristics
* Show `main_arena` address in the `arenas` command output
* Make the heap hueristics support statically linked targets
* Drop some deprecated TLS functions and refactor the command
- Drop some deprecated TLS functions for the deprecated heap heuristics
- Don't call `pthread_self()` in the `tls` command without `-p` option
- Show the page of TLS in the `tls` command output
* Update the hint for the heap heuristics for multi-threaded
* Fix the wrong usage of the exception
* Fix the outdated description
* Return the default global_max_fast when we cannot find the address
* Enhance the output of `arena` and `mp`
- Show the address of the arena we print in the output of `arena` command if we didn't specify the address by ourselves.
- Avoid the bug that `arena` command might get an error if thread_arena doesn't allocate yet.
- Show the address of `mp_` in the output of the `mp` command
* Remove wrong hint
* Support using brute-force to find the address of main_arena
If the user allows, brute-force the left and right sides of the TLS address to find the closest possible value to the TLS address.
* Refactor the code about thread_arena and add the new brute-force strategy
In the .got section, brute-force search for possible TLS-reference values to find possible thread_arena locations
* Add tests for thread_arena and global_max_fast
- Check if we can get default global_max_fast
- Check if we can use brute-force to find thread_arena
* Update the output of `arenas`
* Add the test for the `tls` command
Add two tests for the `tls` command:
```
test_tls_address_and_command[x86-64] PASSED
test_tls_address_and_command[i386] PASSED
```
* Update and refactor the heuristics for `thread_arena` and `tcache`
- We provide an option for users to brute force `tcache` like what we did for `thread_arena`
- Cache `thread_arena` even when we are single-threaded
- Refactor the code for `thread_arena`, to make it work for `tcache` as well
- Update the tests for `tcache`
- Remove some redundant hint
* Fix the wrong cache mechanism
Cache the address of the arena instead of the instance of `Arena`, because `Arena` will cache the value of the field, resulting in getting the old value the next time the same property is used
* Update the description of some configs about heap heuristics
* Handling the case when tcache is NULL
* Handling the case when thread_arena is NULL
* Fix a bug that occurred when the TLS address could not be found
* Fix#1550
* Show tid only if no address is specified
* Update pwndbg/commands/__init__.py
* Update pwndbg/commands/heap.py
* Update pwndbg/commands/heap.py
* Update pwndbg/commands/heap.py
* Update pwndbg/commands/heap.py
* Update pwndbg/commands/heap.py
* Update pwndbg/commands/heap.py
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>
* Fix lint
* Move some code into `pwndbg.gdblib.elf`
---------
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>
* Fix plt and gotplt commands
* Add plt gotplt commands tests
* Fix got and plt commands and test them
* Revert accidental change
* Extend system path
* Hopefully fix PATH problems once and for all?
* fix import
* remove redundant part
* Enhance the checks before accessing the memory
- Use `pwndbg.gdblib.memory.peek()` instead of `pwndbg.gdblib.vmmap.find()` to check if the address is valid
- Directly access the memory when searching the `main_arena` in memory and catch the exception
* Make finding `main_arena` in memory more efficient and reliable
We only try the address that is aligned to `pwndbg.gdblib.arch.ptrsize`
* Avoid unnecessary memory accessing if possible
- Before we used `pwndbg.gdblib.memory.peek()` to check if an address is readable for GDB, we used `pwndbg.gdblib.vmmap.find()` to make sure that this address is in one of the pages, since accessing memory for embedded targets might be slow and expensive
- Create a new function: `is_readable_address` for `pwndbg.gdblib.memory`
* Fix wrong test for `main_arena`
The heap object should be reset before testing the multi-threaded condition
* Add the test to make sure the heap heuristics won't be affected by the vmmap result
Previously, we used `pwndbg.gdblib.vmmap.find()` to check whether the address is valid or not, but this might be a false positive for the address in the `[vsyscall]` page or in the page with a range from 0~0xffffffffffffffff (e.g. qemu-user).
This commit aims to include this scenario during the tests, to make sure the heap heuristics won't be affected by this.
* Use `gdb.MemoryError` instead of `Exception`
* Refactor TLS module
- Replace unreliable `__errno_location()` trick with `pthread_self()` to acquire TLS address
- Consolidate heap heuristics checks about TLS within the `pwndbg.gdblib.tls` module for better organization
* Bug fix for the `errno` command
Calling `__errno_location()` without locking the scheduler can cause another thread to inadvertently continue execution
* Refactor code about heap heuristics of thread-local variables
- Replace some checks with some functions in `pwndbg.gdblib.tls`
- Try to find tcache with `mp_.sbrk_base + 0x10` if the target is single-threaded
* Add tests for heap heuristics with multi-threaded
* Refacotr scheduler-locking related functions
- Move these functions into `pwndbg.gdblib.scheduler`
- Fetch the parameter value once (https://github.com/pwndbg/pwndbg/pull/1536#discussion_r1082549746)
* Avoid bug caused by GLIBC_TUNABLES
See https://github.com/pwndbg/pwndbg/pull/1536#discussion_r1083202815
* Add note about `set scheduler-locking on`
* Add comment for `lock_scheduler`
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>
* Update DEVELOPING.md
Co-authored-by: Disconnect3d <dominik.b.czarnota@gmail.com>
Aaron Adams
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duckl1ng
Disconnect3d
SlidyBat
Matheus Branco Borella
intrigus-lgtm
Alan Li
Gulshan Singh
dan "smiley" murray
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Albert Koczy
CptGibbon
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