From Jan Engelhardt:
Program received signal SIGBUS, Bus error.
[Switching to process 11100]
0x00035278 in kmod_module_signature_info (file=0x4eeb8, sig_info=0xffffc254)
at libkmod/libkmod-signature.c:124
124 sig_len = be32toh(modsig->sig_len);
(gdb) p modsig
$1 = (const struct module_signature *) 0xf7dfe143
modsig->sig_len can be unaligned if modsig is unaligned, so the padding
in the struct has no effect since we are mapping it to the mem buffer.
Commit 51c409b ("Cache the offset of crc") unintentinally changed the
comparison "if (elf->class & KMOD_ELF_32)" to
"if (elf->class == KMOD_ELF_32)".
This has been reported by Serge Voilokov <serge0x76@gmail.com>:
On Raspberry PI elf->class equals KMOD_ELF_32|KMOD_ELF_LSB so
valid condition should be (elf->class & KMOD_ELF_32) instead of
(elf->class == KMOD_ELF_32).
This fixes "modprobe --dump-modversions" failing on 32b systems.
These redirecting makefiles simplifies compiling from some editors and
when CWD is not the root of the source tree. This is similar to what was
introduced in systemd in 340d89e ("build-sys: add small redirecting
Makefiles to simplify compilation from within emacs")
Otherwise, we also parse strings like
BOOT_IMAGE=/boot/vmlinuz-3.12.12-57.g5f654cf-default
In practice, this is not a problem, because there is no module named
BOOT_IMAGE=/boot/vmlinuz-3. It just disturbs in modprobe -c output.
If we can open it and read it, it's good enough for us. Otherwise, we
cannot use -C /dev/null to skip the system configuration for instance:
$ ./tools/modprobe -C /dev/null -c
libkmod: ERROR libkmod/libkmod-config.c:821 conf_files_list: unsupported
file mode /dev/null: 0x21b6
...
Also define noreturn w/o <stdnoreturn.h> and move it to macro.h instead
of in the testsuite.
Based on similar commit on systemd by Shawn Landden
<shawn@churchofgit.com>.
By aligning n_buckets to power of 2 we can turn the "bucket = hashval %
n_buckets" into a less expensive bucket = hashval & (n_buckets - 1).
This removes the DIV instruction as shown below.
Before:
xor %edx,%edx
divl 0x8(%rbx)
mov %edx,%eax
add $0x1,%rax
shl $0x4,%rax
add %rbx,%rax
After:
lea -0x1(%rdi),%edx
and %edx,%eax
add $0x1,%rax
shl $0x4,%rax
add %rbx,%rax
With a microbenchmark, measuring the time to locate the bucket (i.e.
time_to_calculate_hashval + time_to_calculate_bucket_position) we have
the results below (time in clock cycles):
keylen before after
2-10 79.0 61.9 (-21.65%)
11-17 81.0 64.4 (-20.48%)
18-25 90.0 73.2 (-18.69%)
26-32 104.7 87.0 (-16.82%)
33-40 108.4 89.6 (-17.37%)
41-48 111.2 91.9 (-17.38%)
49-55 120.1 102.1 (-15.04%)
56-63 134.4 115.7 (-13.91%)
As expected the gain is constant, regardless of the key length.
The time to clculate the hashval varies with the key length, which
explains the bigger gains for short keys.
Add static inline function to align a value to it's next power of 2.
This is commonly done by a SWAR like the one in:
http://aggregate.org/MAGIC/#Next Largest Power of 2
However a microbench shows that the implementation herer is a faster.
It doesn't really impact the possible user of this function, but it's
interesting nonetheless.
Using a x86_64 i7 Ivy Bridge it shows a ~4% advantage by using clz
instead instead of the OR and SHL chain. And this is by using a BSR
since Ivy Bridge doesn't have LZCNT. New Haswell processors have the
LZCNT instruction which can make this even better. ARM also has a CLZ
instruction so it should be better, too.
Code used to test:
...
v = val[i];
t1 = get_cycles(0);
a = ALIGN_POWER2(v);
t1 = get_cycles(t1);
t2 = get_cycles(0);
v = nlpo2(v);
t2 = get_cycles(t2);
printf("%u\t%llu\t%llu\t%d\n", v, t1, t2, v == a);
...
In which val is an array of 20 random unsigned int, nlop2 is the SWAR
implementation and get_cycles uses RDTSC to measure the performance.
Averages:
ALIGN_POWER2: 30 cycles
nlop2: 31.4 cycles
It's used in so many places without checking, that's really pointless to
check for it in macro.h.
Also remove AC_C_TYPEOF from configure.ac since we don't use -ansi.
Commit 8efede20ef ("Use _Static_assert") introduced the usage of
_Static_assert(). However, _Static_assert() is a fairly new thing,
since it was introduced only in gcc 4.6. In order to support older
compilers, this patch adds a configure.in test that checks whether
_Static_assert() is usable or not, and adjust the behavior of the
assert_cc() macro accordingly.
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.
It occurred to an openSUSE user that our mkinitrd would throw a
warning when used with kmod:
libkmod: conf_files_list: unsupported file mode /dev/null: 0x21b6
Grepping for the error message revealed that there might be a missing
"else" keyword here, since it is unusual to put an "if" directly after
closing brace.
At least in qemu 1.4.1 for vexpress/arm-cortexa9, this resulted in an
illegal instruction error. Solve that by returning an error when
__NR_finit_module is -1.
This reverts commit 38829712e5. It fixes
the problem, but it breaks the testsuite for those who don't have
__NR_finit_module. The testsuite would have to make the same check.
Instead, I'm reverting this change and I'm going to apply another patch
from Jan Luebbe who got this right from the beginning.
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<----------
Add __attribute__((format)) to log_filep() and _show() functions, fixing
the bugs they found in the source code.
For functions that receive va_list instead of being variadic functions
we put 0 in the last argument, so at least the string is checked and we
get warnings of -Wformat-nonliteral type. So, it's better than adding a
pragma here to shut up the warning.
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.
"The secure_getenv() function is intended for use in general-purpose
libraries to avoid vulnerabilities that could occur if set-user-ID or
set-group-ID programs accidentally trusted the environment."
Fix compilation issue with musl-libc:
CC libkmod/libkmod-list.lo
In file included from libkmod/libkmod-private.h:183:0,
from libkmod/libkmod-list.c:24:
libkmod/libkmod-util.h:33:45: warning: 'struct stat' declared inside parameter list [enabled by default]
libkmod/libkmod-util.h:33:45: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
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.
When told to force load a module, we were removing only the value of
vermagic instead of the complete entry.
Philippe De Swert (philippe.deswert@jollamobile.com) sent a patch that
was additionally mangling also the last two chars of the key
("vermagic="). Instead of creating an invalid entry in .modinfo section
like this, this patch removes the complete entry, key + value, by
zeroing the entire string.
Much thanks to Philippe who found the issue and pointed to the fix.
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.
Although the hash table implementation allows passing a callback function
to free a value when it is removed from the hash table, hash_del() wasn't
freeing it if it was provided. Now it does.
As a bonus, it now checks if the callback is set in hash_add() as well.
This is a broken option that only leads to misery and incompatabilities
with other systems. Kbuild doesn't come close to supporting directories
other than /lib/modules with several targets simply failing without
hacky fixes. Simply remove the option and all traces of it, as it
doesn't make sense in today's world.
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.
Only the public header maintains #ifndef in the header, together with
pragma. The other ones contain only pragma.
As reported by Shawn Landden on systemd mailing list this is compatible
with all major compilers and gcc has this since version 3.3.
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
I hate this kind of READV and WRITEV macros that Gustavo seems to love.
clang-analyzer hates them as well.
I'm not motivated enough to refactor this, but I want a clean clang
report, so just shut it up.
If we don't have --gc-sections support, linking kmod fails:
libkmod/.libs/libkmod-util.a(libkmod-util.o): In function 'underscores':
libkmod/libkmod-util.c:117: undefined reference to 'kmod_log'
This is because libkmod-util.la uses kmod_log(), that is in libkmod.la.
Move the function so we don't have a dependency loop while building the
libraries and it works with compilers with no support for --gc-sections.
There's no reason kmod_log should be exported, remove it from linker
script. This doesn't break the API/ABI because we are luck: since the
function had visibility=hidden it was not getting exported as a global
symbol.
This reverts commit 88a170dbd6.
There's no reason for users of the API to call this method, it's just
wrong to export it.
The bug that this patch fixed needs to be fixed another way, not
exporting this function.
zlib won't necessarily set the system errno, and this is particularly
evident on corrupted data (which results in a double free). Use zlib's
gzerror to detect the failure, returning a generic EINVAL when zlib
doesn't provide us with an errno.
If we don't have --gc-sections support, linking kmod fails:
libkmod/.libs/libkmod-util.a(libkmod-util.o): In function 'underscores':
libkmod/libkmod-util.c:117: undefined reference to 'kmod_log'
This is because kmod_log is missing the export define, even though it's
already listed in the exported symbol list.
This matches the change in systemd and udev. Log message on udev's
change by Kay Sievers:
After long consideration we came to the conclusion that user
configuration in /etc should always override the (generally
computer generated) configuration in /run. User configuration
should always be what matters over anything else. Hence rearrange
the search orders accordingly. In general this should change
very little as overriding like this is seldomn done so far,
and the order between /etc and /usr stays the same.
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
Use a function to properly get an unsigned short from memory that is
possibly unaligned.
Note that it implicitly fixes a small bug in the hash function that
was introduced when modifying the eina code: the line "hash ^= key[2]
<< 18;" is supposed to be accessing the 3rd byte of the remainder of
the input, but when 'it' was introduced, 'key' ('data' in eina code)
was no longer incremented, so this ended up accessing the 3rd byte of
the input from the beginning. This is fixed by iterating over 'key',
like the eina code does.
Before this patch depmod was failing on ARMv5 and possibly others that
don't have unaligned access. They do not calculate correctly the
dependencies as shown below:
[root@alarm ~]# modinfo bridge
filename: /lib/modules/2.6.39.4/kernel/net/bridge/bridge.ko
version: 2.3
license: GPL
srcversion: 6B583530AE2B39C7E2317BF
depends: stp,llc
vermagic: 2.6.39.4 preempt mod_unload ARMv5
[root@alarm ~]# depmod
[root@alarm ~]# cat /lib/modules/2.6.39.4/modules.dep |grep bridge
kernel/net/bridge/bridge.ko:
[root@alarm ~]#
See how modinfo properly lists the dependencies, but modules.dep which
depmod generates does not contain them. As a result, most kernel
modules fail to load because their dependencies are not loaded by
modprobe.
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.
Just printing the errno string such as "%m\n" is not enough to help
debug or users understand the problem.
Change to provide more context on the failing operation.
Some messages may happen more than once in the same function and
discovering the line is hard. Now we print the actual log priority
that exposed the message as well as filename and line.
NOTE: We should consider printing the log priority in the non-debug
version as well.
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.
Alias names may contain dots. However since kmod_module_from_alias()
still calls kmod_module_new_from_name(), the bug is not entirely fixed,
and will be completely corrected in a later patch.
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.
Not all libc's have a mtim member in struct stat (dietlibc doesn't).
Change ts_usec() to receive a struct stat as parameter and implement it
accordingly for both cases.
Index dump doesn't use stdio.h function and instead call write()
directly on STDOUT_FILENO file descriptor. Therefore we need to flush
stdio buffers before calling it, to be sure the configuration dump will
appear before index's.
Provide a function to dump the index files to a certain fd. It could be
more optimized (particularly the functions to dump the index that were
copied and pasted from m-i-t), but it seems like the only user of it is
'modprobe -c', used for debugging purposes. So, keep it as is.
Config iterators are useful to get each configuration list, remember its
type and how to get their key/value pair.
softdeps don't have the value yet, because they are stored as string
vectors.
Current limitation is horrible no support to sections: we have to to
have separate header files or to maintain the libkmod-sections.txt file.
We are doing the latter.
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.
Refactor code to use pointer to functions, avoiding the previous
Now comp_types defines a magic header to be checked (size and bytes),
with the associated load() and unload() operations. If a header
matches, their operations are used. Otherwise the regular file
operations (mmap/munmap) are used.
File descriptor close is managed by the common code if it's valid
(>=0). If some code steals the file descriptor (eg: gzopen), then they
must change file->fd to -1.
This way the code should be easier to extend and avoid bugs.
ouch, I did a mess in the original function, fix them:
* on errors (read() < 0), continue reading after the done bytes, not
at position 0.
* read buflen - 1 bytes, so there is always room to store the
trailing \0, as expected by user due behavior of snprintf(),
fgets() and others.
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.
It only worked because n was always 1. kmod_list_remove returns a
pointer to the next element, relative to the removed one. Therefore we
need to always get a pointer to the last.
build: explicitly call PKG_PROG_PKG_CONFIG
Per the manual page, PKG_PROG_PKG_CONFIG needs to be invoked
explicitly if PKG_CHECK_MODULES might not happen (it is indeed stowed
in an AS_IF in kmod). Without this, funny failures can occur.
(As it did.)
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.
Andy Grover
Lucas De Marchi
Michal Marek
Thomas Petazzoni
Jan Engelhardt
Jan Luebbe
Lucas De Marchi
Chengwei Yang
Cristian Rodríguez
Kees Cook
Lucas De Marchi
Aleksey Makarov
Leandro Pereira
Dave Reisner
Mike Frysinger
Kay Sievers
Dan McGee
Ambroz Bizjak
Gustavo Sverzut Barbieri
Pedro Pedruzzi
Thierry Vignaud
Dave Reisner
Leandro Pereira
Jan Engelhardt