With readdir_r() we should be providing enough space to store the dir
name. This could be accomplished by define an union like systemd does:
union dirent_storage {
struct dirent de;
uint8_t storage[offsetof(struct dirent, d_name) +
((NAME_MAX + 1 + sizeof(long)) & ~(sizeof(long) - 1))];
};
However in all places that we use readdir_r() we have no concerns about
reentrance nor we have problems with threads. Thus use the simpler
readdir() instead.
We also remove the error logging here (that could be added back by
checking errno), but it was not adding much value so it's gone.
There are several exported enums by libkmod without document, this patch
mainly added documentation for below enums like the way kmod_resources
be documented in.
* kmod_index
* kmod_remove
* kmod_insert
* kmod_probe
* kmod_filter
* kmod_module_initstate
This is not the best way to document these exported enums, however, it's
the simple way due to gtkdoc limits. It doesn't support export plain
enum like below: see https://bugzilla.gnome.org/show_bug.cgi?id=657444
---------8<-------head.h--------------8<-----------
...
enum foo {
...
};
...
---------8<-------end of head.h-------8<-----------
---------8<-------source.c------------8<-----------
...
/**
* document for foo here
*/
...
typedef enum foo foo;
...
---------8<-------end of source.c-----8<----------
Check for finit_module() and don't use our own static inline function if
there's such function in libc (or another lib).
In testsuite we need to unconditionally define HAVE_FINIT_MODULE because
we want to override this function, and never use the static inline one
in missing.h
Depending on kernel header and simply not passing the flags in
finit_module() if this header is not found is not good.
Add a missing.h header in which stuff like this should be added.
When a module is being loaded directly from disk (no compression, etc),
pass the file descriptor to the new finit_module() syscall. If the
finit_module syscall is exported by the kernel syscall headers, use it.
Additionally, if the kernel's module.h file is available, map kmod flags
to finit_module flags.
If the module is built with CONFIG_MODULE_SIG, add the the signer's
name, hexadecimal key id and hash algorithm to the list returned in
kmod_module_get_info(). The modinfo output then looks like this:
filename: /home/mmarek/kmod/testsuite/rootfs-pristine/test-modinfo/ext4-x86_64-sha256.ko
license: GPL
description: Fourth Extended Filesystem
author: Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others
alias: ext3
alias: ext2
depends: mbcache,jbd2
intree: Y
vermagic: 3.7.0 SMP mod_unload
signer: Magrathea: Glacier signing key
sig_key: E3:C8:FC:A7:3F:B3:1D:DE:84:81:EF:38:E3:4C:DE:4B:0C:FD:1B:F9
sig_hashalgo: sha256
The signature algorithm (RSA) and key identifier type (X509) are not
displayed, because they are constant information for every signed
module. But it would be trivial to add this. Note: No attempt is made at
verifying the signature, I don't think that modinfo is the right tool
for this.
If we are accessing several times the modules and reading some sections
by sucessive calls to the functions below, we are incurring in a penalty
of having to open, parse the header and close the file. For each
function.
- kmod_module_get_info()
- kmod_module_get_versions()
- kmod_module_get_symbols()
- kmod_module_get_dependency_symbols()
These functions are particularly important to depmod. It calls all of
them, for each module. Moreover there's a huge bottleneck in the open
operation if we are using compression. Every time we open the module we
need to uncompress the file and after getting the information we need we
discard the result. This is clearly shown by profiling depmod with perf
(record + report), using compressed modules:
64.07% depmod libz.so.1.2.7 [.] 0x00000000000074b8 ◆
18.18% depmod libz.so.1.2.7 [.] crc32 ▒
2.42% depmod libz.so.1.2.7 [.] inflate ▒
1.17% depmod libc-2.16.so [.] __memcpy_ssse3_back ▒
0.96% depmod [kernel.kallsyms] [k] copy_user_generic_string ▒
0.89% depmod libc-2.16.so [.] __strcmp_sse42 ▒
0.82% depmod [kernel.kallsyms] [k] hrtimer_interrupt ▒
0.77% depmod libc-2.16.so [.] _int_malloc ▒
0.44% depmod kmod-nolib [.] kmod_elf_get_strings ▒
0.41% depmod kmod-nolib [.] kmod_elf_get_dependency_symbols ▒
0.37% depmod kmod-nolib [.] kmod_elf_get_section ▒
0.36% depmod kmod-nolib [.] kmod_elf_get_symbols
...
Average of running depmod 5 times, dropping caches between them, in a
slow spinning disk:
Before: 12.25 +- 0.20
After: 8.20 +- 0.21
m-i-t: 9.62 +- 0.27
So this patch leads to an improvement of ~33% over unpatched version,
ending up with 15% speedup over module-init-tools.
With this flag kmod_module_probe_insert_module() check if module is
blacklisted only if it's also an alias. This is needed in order to allow
blacklisting a module by name and effectively blacklisting all its
aliases as module-init-tools was doing.
Before this patch we could load pcspkr module as follows:
/etc/modprobe.d/test.conf:
alias yay pcspkr
blacklist pcspkr
$ modprobe yay
Now libkmod has support to blacklist "yay" because "pcspkr" is blacklisted.
It makes more sense to have libkmod-config.c deal with the configuration
directly and the others get the config from ctx. As a bonus point we get
a smaller binary. Following numbers are for x86-64, libkmod + kmod:
Before:
text data bss dec hex filename
128840 1496 104 130440 1fd88 tools/modprobe
After:
text data bss dec hex filename
128392 1496 104 129992 1fbc8 tools/modprobe
If kernel doesn't have support to unload modules,
/sys/module/<modname>/refcnt will not exist and that's ok.
Reported by: Sven Anders <anders@anduras.de>
This is a more generic method of applying filters to module lists. This
deprecates kmod_module_get_filtered_blacklist() which now simply returns
a call to _apply_filter with the extra filter enum arg.
Running two instances of modprobe with the same module should both
succeed or both fail:
modprobe foo&; modprobe foo;
Previously if foo failed to be inserted by the first call, the second one
could return 0 because it may have occurred while the first one was being
processed by kernel (thus marked as "coming").
Now we simply don't check by "coming" in order to decide if we need to
call init_module(). module-init-tools used to spin calling
usleep(100000), but calls to init_module() are already synchronous.
Therefore let kernel synchronize the calls.
Search modules.builtin file before saying the module was not found.
Note: these "modules" should not appear as dependencies of other modules
(in modules.dep) even if they appear in modinfo. This fixes the return
code of modprobe with builtin modules.
Also fixes a small coding style issue in module_is_inkernel().
If a softdep depends on a module in the dependency list of the module
being inserted, we would enter and infinite loop.
Move the "mod->visited = true" assignment to the proper place, hoping it
didn't break other use cases. This is a bug that comes and goes every
now and then. Since we have a testsuite now, a test for this should be
written.
Commit "af9572c lib/module: check initstate before inserting module"
removed the check for "we should return -EEXIST" and moved it back to
the start of the function. The problem with this is the following
scenario:
- We check if module is in kernel -> no
- We insert the dependencies
<-- External program loads
the module
- We check if module is in kernel -> yes
- We return 0, when we should return -EEXIST
This applies to both the high level probe_insert_module() and the
underlying insert_module() functions. By checking module initstate prior
to inserting a module, we can avoid a lot of needless work just to find
out that the init_module call fails with EEXIST.
This implements a helper function, module_is_inkernel, to return a
boolean value describing if a module is live, coming, or builtin.
We need a way to tell libkmod to ignore loaded modules, so modprobe can
tell it to dry-run and show dependencies. However there's a conflict
with two flags. KMOD_PROBE_STOP_ON_ALREADY_LOADED prevails if passed
together with KMOD_PROBE_IGNORE_LOADED.
It's not as simple as tell user to check if the module is loaded before
calling this function. Due to race conditions, module might not be
loaded before the function call, but fail later because another process
inserted it.
Share code of module creation among the several new functions. With this
we let the alias/modname/path parsing to the separate functions, and the
rest with the common one.
This fixes the issue of alias names not being able to contain dots.
Split kmod_module_probe_insert_module() in 2:
1) Get list of modules to be loaded
2) Iterate the list, loading the module
With this in future we will be able to cover use cases of modprobe,
that has a logic a bit more complicated.
With this we also change the logic to detect dependency loops: instead
of checking the recursion every STEP times, we now keep a field in
kmod_module, marking it as visited. We simply ignore already visited
modules and thus we break loops.
This field can be used to iterate the modules, controlling whether we
are revisiting a certain module. A function to clear the values in all
modules is needed since when we are iterating, we don't know if the
module is created anew or if it's picked from the pool. Therefore we
can't know if the field is true because of a previous iteration or if
the module was indeed already visited.
Lucas De Marchi
Chengwei Yang
Lucas De Marchi
Kees Cook
Michal Marek
Lucas De Marchi
Dave Reisner
Kay Sievers
Dan McGee
Thierry Vignaud