The length of the name was passed, and the name may not be
null-terminated.
Fixes: 565e0343ef ("libdrgn: make symbol index pluggable with callbacks")
Signed-off-by: Omar Sandoval <osandov@osandov.com>
table_insert_searched() returns -1 when insertion fails.
Fixes: d1beb0184a ("libdrgn: add support for objects in C++ namespaces")
Signed-off-by: Omar Sandoval <osandov@osandov.com>
index_die() can only fail if it's out of memory, so return a bool
instead of a struct drgn_error. Also clean up the declarations.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Also:
* Rename struct string to struct nstring and move it to its own header.
* Fix scripts/iwyu.py, which was broken by commit 5541fad063 ("Fix
some flake8 errors").
* Add workarounds for a few outstanding include-what-you-use issues.
There is still a false positive for
include-what-you-use/include-what-you-use#970, but hopefully that is
fixed soon.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Commit dd503c975ab3 ("Fix kdump_vmcoreinfo_raw()") in libkdumpfile
changed the buffer returned by kdump_vmcoreinfo_raw() to be dynamically
allocated. We need to free it on versions containing that change.
Closes#76.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Stephen Brennan reported a flaky test while working on #121:
======================================================================
ERROR: test_by_task_struct (tests.helpers.linux.test_stack_trace.TestStackTrace)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/runner/work/drgn/drgn/tests/helpers/linux/test_stack_trace.py", line 22, in test_by_task_struct
self.assertIn("pause", str(self.prog.stack_trace(find_task(self.prog, pid))))
ValueError: cannot unwind stack of running task
The problem is that the stack trace tests wait for the thread state to
change to "S". However, the state is updated while the thread is still
technically running. For example, the pause() system call is implemented
as:
SYSCALL_DEFINE0(pause)
{
while (!signal_pending(current)) {
__set_current_state(TASK_INTERRUPTIBLE);
schedule();
}
return -ERESTARTNOHAND;
}
If Program.stack_trace() accesses the thread after the state is changed
but before the thread has actually been scheduled out (namely, before
task_struct::on_cpu is set to 0), it will fail.
Instead, let's check /proc/$pid/syscall, which contains "running" until
the thread is completely scheduled out.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
* Mention installing drgn using a package manager on Fedora/EPEL.
Closes#103.
* Mention that pip installs a binary wheel by default.
* Include instructions for installing from source in README.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
As of commit 0cf3320a89 ("Add type annotations to helpers"), helpers
have type annotations instead of C signatures.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
viewcode works by importing modules. This doesn't actually work on Read
the Docs because we don't build and install the C extension. It looks
like there are workarounds (viewcode-find-source), but let's disable it
for now.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
I couldn't find any good summaries of how to get debugging symbols on
various distros, so I guess we'll have to maintain our own.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
The overloaded version is slower to compile, and we don't actually need
it. We can add a variadic version if we need to in the future. Also add
the script used to generate the macros.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Jay pointed out that when finding the ancestors for a DIE, we should use
DW_AT_sibling to skip over subtrees that can't contain the target DIE.
So, let's check each DIE that we encounter for a DW_AT_sibling
attribute. dwarf_attr() also returns the end of the DIE if it doesn't
find the attribute, which we can use to avoid parsing DIEs redundantly.
This doesn't fit very well into drgn_dwarf_iterator, so let's just
hand-roll this special type of iteration. In my measurements, this made
drgn_find_die_ancestors() ~6x as fast on average.
Closes#124.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Previously shards were allocated as soon as a namespace was
encountered, which means that we had a large array sitting around for
every ns we saw. By allocating them lazily, we can reduce this usage.
Signed-off-by: Jay Kamat <jaygkamat@gmail.com>
DEFINE_HASH_TABLE_TYPE() doesn't actually need to know the key type.
Move that argument (and some of the derived constants) to
DEFINE_HASH_TABLE_FUNCTIONS(). This will allow recursive hash table
types. As a nice side effect, it also reduces the size of common header
files.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
The underscore was meant to discourage direct access in favor of using
drgn_program_get_dbinfo(), but it turns out that it's more normal to
access it directly.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
The only time that we want to create the drgn_debug_info is when we're
loading debugging information. Everywhere else, we fail fast if there is
no debugging information.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
drgnpy_linux_helper_task_state_to_char() was removed by commit
ff96c75da0 ("helpers: translate task_state_to_char() to Python"), but
I left behind the declaration.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Once we've cleared the pending DIEs vector, we won't use the vector
again (unless we load more debugging information), so we can free it.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
When linking libdrgn as a static library, the name 'splay_tree' can
conflict with splay-tree.h in libiberty (namely splay_tree_splay).
Rename relevant functions to have a 'drgn_' prefix
Signed-off-by: Jake Hillion <jakehillion@fb.com>
In larger binaries, there can be a large number of CUs, and since we
store an abbrev table for each CU the extra space starts to add up.
The simplest way to mitigate this is to shrink the vectors before
saving them.
On a large binary, I noticed a memory reduction from 20.4G RES to
18.6G RES (on initial load-in).
These haven't been running in vmtest since they were added. Enable
cgroup2 in vmtest and rework the cgroup tests to create cgroups that we
can test with.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Add a helper, qdisc_lookup(), to get a Qdisc (struct Qdisc *) from a
network device and a major handle number. As an example:
>>> eth0 = netdev_get_by_name(prog, "eth0")
>>> tbf = qdisc_lookup(eth0, 0x20)
>>> tbf.ops.id.string_().decode()
tbf
>>> ingress = qdisc_lookup(eth0, 0xffff)
>>> ingress.ops.id.string_().decode()
ingress
Testing depends on pyroute2. `TestTc` is skipped if pyroute2 is not
found; test_qdisc_lookup() is skipped if the kernel is not built with the
following options:
CONFIG_DUMMY
CONFIG_NET_SCH_PRIO
CONFIG_NET_SCH_SFQ
CONFIG_NET_SCH_TBF
CONFIG_NET_SCH_INGRESS
Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Add a helper, netdev_for_each_tx_queue(), to iterate over all TX queues of
a network device. As an example:
>>> eth0 = netdev_get_by_name(prog, "eth0")
>>> for txq in netdev_for_each_tx_queue(eth0):
... print(txq.qdisc.ops.id.string_().decode())
...
sfq
tbf
prio
pfifo_fast
Set up `net` in setUpClass(), since now several tests use it. Also use
it in test_netdev_get_by_{index,name}(), instead of assuming `init_net`.
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
We're seeing some hangs waiting for entropy when running tests, so let's
enable the virtio-rng module. While we're doing a rebuild, we might as
well enable cgroups so that we can finally run those tests.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
This already caches class variables, and it's shared across all Linux
helper test cases, so it makes more sense as setUpClass. This will also
allow subclasses to use cls.prog in their own setUpClass.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
And use it in a few appropriate places. This should hopefully make it
harder to make iteration mistakes like the one fixed by commit
4755cfac7c ("libdrgn: dwarf_index: increment correct variable when
rolling back"). While we're doing this, move ARRAY_SIZE() into a new
header file with array_for_each() and make it lowercase.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
We need to increment to the next DIE, not the next shard here.
Fixes: 1c9ab2e7d1 ("libdrgn: dwarf_index: fix leak of DWARF index entries on failure")
Signed-off-by: Omar Sandoval <osandov@osandov.com>
The "k" format expects an unsigned long, so make sure we cast C enums to
the proper type. This probably doesn't matter for x86 in practice, but
it's better to be safe.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Add a helper, get_net_ns_by_inode(), to get the network namespace
("netns") descriptor (struct net *) given an netns NSFS pseudo-file
inode (struct inode *) e.g. "/proc/$PID/ns/net" or "/run/netns/$NAME".
As an example:
>>> inode = path_lookup(prog, "/run/netns/foo").dentry.d_inode
>>> net = get_net_ns_by_inode(inode)
>>> netdev = netdev_get_by_name(net, "eth3")
>>> netdev.ifindex.value_()
5
Conventionally ip netns files can be found under "/var/run/netns/",
while Docker netns files can be found under "/var/run/docker/netns".
However, as pointed out by Omar, path_lookup() doesn't know how to
deal with symlinks; resolve it using something like "pwd -P" before
passing it to path_lookup().
Also add a get_net_ns_by_fd() wrapper around it as suggested by Omar.
Example:
>>> import os
>>> pid = os.getpid()
>>> task = find_task(prog, pid)
>>> file = open(f"/proc/{pid}/ns/net")
>>> net = get_net_ns_by_fd(task, file.fileno())
Add a test for get_net_ns_by_inode().
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Read the Docs defaults to Sphinx 1.8.5. This version was released in
2019 and doesn't know about the :classmethod: option, so the
documentation for Object.from_bytes_() is missing from
drgn.readthedocs.io. Set the required version to the current latest
version as recommended by Read the Docs:
https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html#pinning-dependencies.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Add a helper to iterate over all network namespaces in the system. As
an example:
>>> for net in for_each_net(prog):
... if netdev_get_by_name(net, "enp0s3"):
... print(net.ipv4.sysctl_ip_early_demux.value_())
...
1
Also add a test for this new helper to tests/helpers/linux/test_net.py.
Suggested-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
QEMU warns about the default 8k msize
(https://wiki.qemu.org/Documentation/9psetup#msize). I wasn't able to
measure any performance difference, but bump it to 1MiB to silence the
warning.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
