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.
Module aliases can be bigger than NAME_MAX. So, replace with PATH_MAX
that is bigger enough to hold them.
Technically in some places NAME_MAX would be sufficient (those using
module names only), but they use functions that can be called with
alias. So increase the buffers in these cases to PATH_MAX too.
Return -errno instead of the value returned by init_module(). We need to
differentiate between the several errors that might occur, e.g. "module
already loaded", access denied, etc.
Treat module insertion as modprobe does: look for (soft-)dependencies, run
install commands, apply blacklist.
The difference with the blacklist is that it's applied to all modules,
including the dependencies. If you want to apply a blacklist only on the
module it's better to call the filter function by yourself.
This implementation detects loops caused by poorly written
soft-dependencies and fail gracefully, printing the loop to the log.
Uses kmod_elf_get_dependency_symbols() that looks into ".symtab" for
UNDEF symbols and matches the name from ".strtab" to "__versions" to
get crc.
Likely the public API should unify the symbol information getters and
list release, they are almost the same.
Similar to module-init-tools load_symbols(), it will try .symtab and
.strtab for symbols starting with __crc_, if they are found their crc
is read from ELF's Elf_Sym::st_value.
If not found, then it will fallback to __ksymtab_strings.
