The sd_device object always has syspath and sysname, but subsytem may not.
Also, it may take some costs to get subsystem.
So, let's drop subsystem from logs.
All over the place we define local variables for the various sockopts
that take a bool-like "int" value. Sometimes they are const, sometimes
static, sometimes both, sometimes neither.
Let's clean this up, introduce a common const variable "const_int_one"
(as well as one matching "const_int_zero") and use it everywhere, all
acorss the codebase.
Let's use structured initialization, but more importantly, let's
increase salen by 1, if we reference AF_UNIX sockets in the file system,
so that they also contain the trailing NUL byte. This is what unix(7)
suggests to do, hence follow it.
Insist on NUL termination, just to be safe rather than sorry. The kernel
doesn't require it, but it's really annoying if people rely on this,
hence refuse this early.
This is actually a u16, not a u32, so the kernel complains:
kernel: netlink: 'systemd-network': attribute type 5 has an invalid length
This is due to:
if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) {
pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
current->comm, type);
}
Presumably this has been working fine in functionality on little-endian
systems, but nobody bothered to try on big-endian systems.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Mempool use is enabled or disabled based on the mempool_use_allowed symbol that
is linked in.
Should fix assert crashes in external programs caused by #9792.
Replaces #10286.
v2:
- use two different source files instead of a gcc constructor
linux/capability.h's CAP_TO_MASK potentially shifts a signed int "1"
(i.e. 32bit wide) left by 31 which means it becomes negative. That's
just weird, and ubsan complains about it. Let's introduce our own macro
CAP_TO_MASK_CORRECTED which doesn't fall into this trap, and make use of
it.
Fixes: #10347
We would read (-1), and then add 1 to it, call message_peek_body(..., 0, ...),
and when trying to make use of the data.
The fuzzer test case is just for one site, but they all look similar.
v2: fix two UINT8_MAX/UINT32_MAX mismatches founds by LGTM
We copied part of the string into a buffer that was off by two.
If the element signature had length one, we'd copy 0 bytes and crash when
looking at the "first" byte. Otherwise, we would crash because strncpy would
not terminate the string.
This is similar to the grandparent commit 'fix calculation of offsets table',
except that now the change is for array elements. Same story as before: we need
to make sure that the offsets increase enough taking alignment into account.
While at it, rename 'p' to 'previous' to match similar code in other places.
The offsets specify the ends of variable length data. We would trust the
incoming data, putting the offsets specified in our message
into the offsets tables after doing some superficial verification.
But when actually reading the data we apply alignment, so we would take
the previous offset, align it, making it bigger then current offset, and
then we'd try to read data of negative length.
In the attached example, the message specifies the following offsets:
[1, 4]
but the alignment of those items is
[1, 8]
so we'd calculate the second item as starting at 8 and ending at 4.
The alternative would be to treat gvariant and !gvariant messages differently.
But this is a problem because we check signatures is variuos places before we
have an actual message, for example in sd_bus_add_object_vtable(). It seems
better to treat things consistent (i.e. follow the lowest common denominator)
and disallow empty structures everywhere.
We didn't free one of the fields in two of the places.
$ valgrind --show-leak-kinds=all --leak-check=full \
build/fuzz-bus-message \
test/fuzz/fuzz-bus-message/leak-c09c0e2256d43bc5e2d02748c8d8760e7bc25d20
...
==14457== HEAP SUMMARY:
==14457== in use at exit: 3 bytes in 1 blocks
==14457== total heap usage: 509 allocs, 508 frees, 51,016 bytes allocated
==14457==
==14457== 3 bytes in 1 blocks are definitely lost in loss record 1 of 1
==14457== at 0x4C2EBAB: malloc (vg_replace_malloc.c:299)
==14457== by 0x53AFE79: strndup (in /usr/lib64/libc-2.27.so)
==14457== by 0x4F52EB8: free_and_strndup (string-util.c:1039)
==14457== by 0x4F8E1AB: sd_bus_message_peek_type (bus-message.c:4193)
==14457== by 0x4F76CB5: bus_message_dump (bus-dump.c:144)
==14457== by 0x108F12: LLVMFuzzerTestOneInput (fuzz-bus-message.c:24)
==14457== by 0x1090F7: main (fuzz-main.c:34)
==14457==
==14457== LEAK SUMMARY:
==14457== definitely lost: 3 bytes in 1 blocks
v2: fix error in free_and_strndup()
When the orignal and copied message were the same, but shorter than specified
length l, memory read past the end of the buffer would be performed. A test
case is included: a string that had an embedded NUL ("q\0") is used to replace
"q".
v3: Fix one more bug in free_and_strndup and add tests.
v4: Some style fixed based on review, one more use of free_and_replace, and
make the tests more comprehensive.
Both 'systemd-hwdb update' and 'udevadm hwdb --update' creates hwdb
database. The database created by systemd-hwdb containes additional
information such that priority, line number, and source filename.
The unified function 'hwdb_update()' can take a flag 'compat' which
controls the format version of created database.
This work add support to generic netlink to sd-netlink.
See https://lwn.net/Articles/208755/
networkd: add support FooOverUDP support to IPIP tunnel netdev
https://lwn.net/Articles/614348/
Example conf:
/lib/systemd/network/1-fou-tunnel.netdev
```
[NetDev]
Name=fou-tun
Kind=fou
[FooOverUDP]
Port=5555
Protocol=4
```
/lib/systemd/network/ipip-tunnel.netdev
```
[NetDev]
Name=ipip-tun
Kind=ipip
[Tunnel]
Independent=true
Local=10.65.208.212
Remote=10.65.208.211
FooOverUDP=true
FOUDestinationPort=5555
```
$ ip -d link show ipip-tun
```
5: ipip-tun@NONE: <POINTOPOINT,NOARP> mtu 1472 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ipip 10.65.208.212 peer 10.65.208.211 promiscuity 0
ipip remote 10.65.208.211 local 10.65.208.212 ttl inherit pmtudisc encap fou encap-sport auto encap-dport 5555 noencap-csum noencap-csum6 noencap-remcsum numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
```
--machine has been missing for a while in systemd-stdio-bridge
this syntax can be switched to be more standard.
v2: Support the old syntax too.
timedatectl -H server1.myhostingcompany.com:5555/container1
Closes: #8071
We would verify destination e.g. in sd_bus_message_new_call, but allow setting
any value later on with sd_bus_message_set_destination. I assume this check was
omitted not on purpose.
When a nested struct is initialized by structured initializer, then
padding space is not cleared by zero. So, before setting values,
this makes explicitly set zero including padding.
This fixes the following false positive warning by valgrind:
```
==492== Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
==492== at 0x56D0CF7: sendmsg (in /usr/lib64/libpthread-2.27.so)
==492== by 0x4FDD3C5: sd_resolve_getaddrinfo (sd-resolve.c:975)
==492== by 0x110B9E: manager_connect (timesyncd-manager.c:879)
==492== by 0x10B729: main (timesyncd.c:165)
==492== Address 0x1fff0008f1 is on thread 1's stack
==492== in frame #1, created by sd_resolve_getaddrinfo (sd-resolve.c:928)
==492==
```
machined exposes the pseudo-container ".host" as a reference to the host
system, and this means "machinectl login .host" and "machinectl shell
.host" get your a login/shell on the host. systemd-run currently doesn't
allow that. Let's fix that, and make sd-bus understand ".host" as an
alias for connecting to the host system.
This makes bus_slot_disconnect() unref the slot object from bus when
`unref == true` and it is floating, as the function removes the
reference from the relevant bus object.
This reverts 20d4ee2cbc, as it
introduces #9604.
Fixes#9604.
The switch to memory_startswith() changed the logic to only look for a space or
NUL byte after the matched word, but matching the full size should also be
acceptable.
This changed the behavior of parsing of "AUTH\r\n", where m will be set to 4,
since even though the word will match, the check for it being followed by ' '
or NUL will make line_begins() return false.
Tested:
- Using netcat to connect to the private socket directly:
$ echo -ne '\0AUTH\r\n' | sudo nc -U /run/systemd/private
REJECTED EXTERNAL ANONYMOUS
- Running the Ignition blackbox test:
$ sudo sh -c 'PATH=$PWD/bin/amd64:$PATH ./tests.test'
PASS
Fixes: d27b725abf
This adds sd_bus_{get,set}_method_call_timeout().
If the timeout is not set or set to 0, then the timeout value is
parsed from $SYSTEMD_BUS_TIMEOUT= environment variable. If the
environment variable is not set, then built-in timeout is used.
When a slot is disconnected, then slot->match_callback.install_slot
is also disconnected. So, bus_slot_disconnect() removes the install_slot
from the list of slots in bus, although it is a floating object.
This makes install_slot unreffed from bus when it is disconnected.
Fixes#9505 and #9510.
The D-Bus library supplies a va_list variant of
`sd_bus_message_append()` called `sd_bus_message_appendv()`,
but failed to provide a va_list variant of its opposite,
`sd_bus_message_read()`. This commit publicizes a previously static
function as `sd_bus_message_readv()`.
This makes OBJECT_PATH_FOREACH_PREFIX consistent with PATH_FOREACH_PREFIX
and also fixes 7 alerts reported by LGTM at
ac0a087003/files/src/libsystemd/sd-bus/bus-objects.c?sort=name&dir=ASC&mode=heatmap&showExcluded=true#V1383
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Let's always write "1 << 0", "1 << 1" and so on, except where we need
more than 31 flag bits, where we write "UINT64(1) << 0", and so on to force
64bit values.
Since bb28e68477 parsing failures of
certain unit file settings will result in load failures of units. This
introduces a new load state "bad-setting" that is entered in precisely
this case.
With this addition error messages on bad settings should be a lot more
explicit, as we don't have to show some generic "errno" error in that
case, but can explicitly say that a bad setting is at fault.
Internally this unit load state is entered as soon as any configuration
loader call returns ENOEXEC. Hence: config parser calls should return
ENOEXEC now for such essential unit file settings. Turns out, they
generally already do.
Fixes: #9107
This adds a function sd_bus_slot_set_destroy_callback() to set a function
which can free userdata or perform other cleanups.
sd_bus_slot_get_destory_callback() queries the callback, and is included
for completeness.
Without something like this, for floating asynchronous callbacks, which might
be called or not, depending on the sequence of events, it's hard to perform
resource cleanup. The alternative would be to always perform the cleanup from
the caller too, but that requires more coordination and keeping of some shared
state. It's nicer to keep the cleanup contained between the callback and the
function that requests the callback.
This tests a couple of corner cases of the sd-event API including
changing priorities of existing event sources, as well as overflow
conditions of the inotify queue.
This adds a new call sd_event_add_inotify() which allows watching for
inotify events on specified paths.
sd-event will try to minimize the number of inotify fds allocated, and
will try to add file watches to the same inotify fd objects as far as
that's possible. Doing this kind of inotify object should optimize
behaviour in programs that watch a limited set of mostly independent
files as in most cases a single inotify object will suffice for watching
all files.
Traditionally, this kind of coalescing logic (i.e. that multiple event
sources are implemented on top of a single inotify object) was very hard
to do, as the inotify API had serious limitations: it only allowed
adding watches by path, and would implicitly merge watches installed on
the same node via different path, without letting the caller know about
whether such merging took place or not.
With the advent of O_PATH this issue can be dealt with to some point:
instead of adding a path to watch to an inotify object with
inotify_add_watch() right away, we can open the path with O_PATH first,
call fstat() on the fd, and check the .st_dev/.st_ino fields of that
against a list of watches we already have in place. If we find one we
know that the inotify_add_watch() will update the watch mask of the
existing watch, otherwise it will create a new watch. To make this
race-free we use inotify_add_watch() on the /proc/self/fd/ path of the
O_PATH fd, instead of the original path, so that we do the checking and
watch updating with guaranteed the same inode.
This approach let's us deal safely with inodes that may appear under
various different paths (due to symlinks, hardlinks, bind mounts, fs
namespaces). However it's not a perfect solution: currently the kernel
has no API for changing the watch mask of an existing watch -- unless
you have a path or fd to the original inode. This means we can "merge"
the watches of the same inode of multiple event sources correctly, but
we cannot "unmerge" it again correctly in many cases, as access to the
original inode might have been lost, due to renames, mount/unmount, or
deletions. We could in theory always keep open an O_PATH fd of the inode
to watch so that we can change the mask anytime we want, but this is
highly problematics, as it would consume too many fds (and in fact the
scarcity of fds is the reason why watch descriptors are a separate
concepts from fds) and would keep the backing mounts busy (wds do not
keep mounts busy, fds do). The current implemented approach to all this:
filter in userspace and accept that the watch mask on some inode might
be higher than necessary due to earlier installed event sources that
might have ceased to exist. This approach while ugly shouldn't be too
bad for most cases as the same inodes are probably wacthed for the same
masks in most implementations.
In order to implement priorities correctly a seperate inotify object is
allocated for each priority that is used. This way we get separate
per-priority event queues, of which we never dequeue more than a few
events at a time.
Fixes: #3982
The function is similar to path_kill_slashes() but also removes
initial './', trailing '/.', and '/./' in the path.
When the second argument of path_simplify() is false, then it
behaves as the same as path_kill_slashes(). Hence, this also
replaces path_kill_slashes() with path_simplify().
This "netdevsim" as implied by the name is a tool for network developers and is a simulator.
This simulated networking device is used for testing various networking APIs and at this time
is particularly focused on testing hardware offloading related interfaces.
We currently return -ENOMEDIUM when /etc/machine-id is empty, and -EINVAL when
it is all zeros. But -EINVAL is also used for invalid args. The distinction
between empty and all-zero is not very important, let's use the same return
code.
Also document -ENOENT and -ENOMEDIUM since they can be a bit surprising.
When we allocate an asynchronous match object we will allocate an
asynchronous bus call object to install the match server side.
Previously the call slot would be created as regular slot, i.e.
non-floating which meant installing the match even if it was itself
floating would result in a non-floating slot to be created internally,
which ultimately would mean the sd_bus object would be referenced by it,
and thus never be freed.
Let's fix that by making the match method callback floating in any case
as we have no interest in leaving the bus allocated beyond the match
slot.
Fixes: #8551
This new call allows explicit control of the "floating" state of a bus
slot object. This is useful for creating a bus slot object first,
retaining a reference to it, using it for making changes to the slot
object (for example, set a description) and then handing it over to
sd-bus for lifecycle management.
It's also useful to fix#8551.
This adds a small service "systemd-portabled" and a matching client
"portablectl", which implement the "portable service" concept.
The daemon implements the actual operations, is PolicyKit-enabled and is
activated on demand with exit-on-idle.
Both the daemon and the client are an optional build artifact, enabled
by default rhough.
Most our other parsing functions do this, let's do this here too,
internally we accept that anyway. Also, the closely related
load_env_file() and load_env_file_pairs() also do this, so let's be
systematic.
Let's tweak the assignment of errors a bit, and automatically abs()
errnos, similar to how log_error_errno() and friends does it.
Macros are fine to use, but regular functions usually preferable if
there's no reason to use macros, because they avoid multiple evaluation
and suchlike. Hence, let's just use a regular funciton for assigning
errors, instead of macros.
Follow-up for #8993
The protocol is that a string is serialized with the nul byte at the end, and
the terminator is included in length. We'd call strndup with offset 0, length
len1-1, and then a second time with offset len1, length len2-1, so in the end
the check was off by one. But let's require the terminating nul too, even if
we don't access it.
CID #1383035.
This is external data, even if trusted. We should not assert on it, but verify
and return proper error instead, which assert_return does. In particular,
write(2) says that a partial write could occur when interupted by a signal.
When compiled with asserts disabled, we could access memory outside of the
allocated buffer.
CID #1237671.
Follow-up for 1a96c8e1cc.
We were inconsitently using them in some cases, but in majority not.
Using assignment in assert_se is very common, not an exception like in
'if', so let's drop the extra parens everywhere.
The leak can be reproduced by running systemd-path --suffix .tmp under valgrind or asan:
$ ./build/systemd-path --suffix .tmp search-binaries
/usr/local/bin/.tmp:/usr/bin/.tmp:/usr/local/sbin/.tmp:/usr/sbin/.tmp:/home/vagrant/.local/bin/.tmp:/home/vagrant/bin/.tmp
=================================================================
==19177==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 56 byte(s) in 1 object(s) allocated from:
*0 0x7fd6adf72850 in malloc (/lib64/libasan.so.4+0xde850)
*1 0x7fd6ad2b93d2 in malloc_multiply ../src/basic/alloc-util.h:69
*2 0x7fd6ad2bafd2 in strv_split ../src/basic/strv.c:269
*3 0x7fd6ad42ba67 in search_from_environment ../src/libsystemd/sd-path/sd-path.c:409
*4 0x7fd6ad42bffe in get_search ../src/libsystemd/sd-path/sd-path.c:482
*5 0x7fd6ad42c55b in sd_path_search ../src/libsystemd/sd-path/sd-path.c:607
*6 0x7fd6ad42b3a2 in sd_path_home ../src/libsystemd/sd-path/sd-path.c:348
*7 0x55f59c65ebea in print_home ../src/path/path.c:97
*8 0x55f59c65f157 in main ../src/path/path.c:177
*9 0x7fd6abaea009 in __libc_start_main (/lib64/libc.so.6+0x21009)
Indirect leak of 68 byte(s) in 5 object(s) allocated from:
*0 0x7fd6adf72850 in malloc (/lib64/libasan.so.4+0xde850)
*1 0x7fd6abb5f689 in strndup (/lib64/libc.so.6+0x96689)
Indirect leak of 25 byte(s) in 1 object(s) allocated from:
*0 0x7fd6adf72850 in malloc (/lib64/libasan.so.4+0xde850)
*1 0x7fd6abb5f689 in strndup (/lib64/libc.so.6+0x96689)
*2 0x6c2e2f746e617266 (<unknown module>)
SUMMARY: AddressSanitizer: 149 byte(s) leaked in 7 allocation(s).
Previously we were a bit sloppy with the index and size types of arrays,
we'd regularly use unsigned. While I don't think this ever resulted in
real issues I think we should be more careful there and follow a
stricter regime: unless there's a strong reason not to use size_t for
array sizes and indexes, size_t it should be. Any allocations we do
ultimately will use size_t anyway, and converting forth and back between
unsigned and size_t will always be a source of problems.
Note that on 32bit machines "unsigned" and "size_t" are equivalent, and
on 64bit machines our arrays shouldn't grow that large anyway, and if
they do we have a problem, however that kind of overly large allocation
we have protections for usually, but for overflows we do not have that
so much, hence let's add it.
So yeah, it's a story of the current code being already "good enough",
but I think some extra type hygiene is better.
This patch tries to be comprehensive, but it probably isn't and I missed
a few cases. But I guess we can cover that later as we notice it. Among
smaller fixes, this changes:
1. strv_length()' return type becomes size_t
2. the unit file changes array size becomes size_t
3. DNS answer and query array sizes become size_t
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=76745
This cleans up handling of MTU values across the codebase. Previously
MTU values where stored sometimes in uint32_t, sometimes in uint16_t,
sometimes unsigned and sometimes in size_t. This now unifies this to
uint32_t across the codebase, as that's what netlink spits out, and what
the majority was already using.
Also, all MTU parameters are now parsed with config_parse_mtu() and
config_parse_ipv6_mtu() is dropped as it is now unneeded.
(Note there is one exception for the MTU typing: in the DCHPv4 code we
continue to process the MTU as uint16_t value, as it is encoded like
that in the protocol, and it's probably better stay close to the
protocol there.)
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.
It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
sd_bus_open/sd_bus_open_system/sd_bus_open_user are convenient, but
don't allow the description to be set. After they return, the bus is
is already started, and sd_bus_set_description() fails with -EBUSY.
It would be possible to allow sd_bus_set_description() to update the
description "live", but messages are already emitted from sd_bus_open
functions, so it's better to allow the description to be set in
sd_bus_open/sd_bus_open_system/sd_bus_open_user.
Fixes message like:
Bus n/a: changing state UNSET → OPENING
This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
kernel >= 4.5 (with commit 32bc201e19) supports
RTA_EXPIRES netlink attribute to set router lifetime. This simply detect
the kernel version (>=4.5) and set the lifetime properly, fallback to
expiring route in userspace for kernel that doesnt support it.
Signed-off-by: Daniel Dao <dqminh89@gmail.com>
Some versions of asan report the following false positive
when strict_string_checks=1 is passed:
=================================================================
==3297==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x7f64e4090286 bp 0x7ffe46acd9a0 sp 0x7ffe46acd118 T0)
==3297==The signal is caused by a READ memory access.
==3297==Hint: address points to the zero page.
#0 0x7f64e4090285 in __strlen_sse2 (/lib64/libc.so.6+0xaa285)
#1 0x7f64e5a51e46 (/lib64/libasan.so.4+0x41e46)
#2 0x7f64e4e5e3a0 (/lib64/libglib-2.0.so.0+0x383a0)
#3 0x7f64e4e5e536 in g_dgettext (/lib64/libglib-2.0.so.0+0x38536)
#4 0x7f64e48fac5f (/lib64/libgio-2.0.so.0+0xc1c5f)
#5 0x7f64e4c03978 in g_type_class_ref (/lib64/libgobject-2.0.so.0+0x30978)
#6 0x7f64e4be9567 in g_object_new_with_properties (/lib64/libgobject-2.0.so.0+0x16567)
#7 0x7f64e4be9fd0 in g_object_new (/lib64/libgobject-2.0.so.0+0x16fd0)
#8 0x7f64e48fd43e in g_dbus_message_new_from_blob (/lib64/libgio-2.0.so.0+0xc443e)
#9 0x564a6aa0de52 in main ../src/libsystemd/sd-bus/test-bus-marshal.c:228
#10 0x7f64e4007009 in __libc_start_main (/lib64/libc.so.6+0x21009)
#11 0x564a6aa0a569 in _start (/home/vagrant/systemd/build/test-bus-marshal+0x5569)
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/lib64/libc.so.6+0xaa285) in __strlen_sse2
==3297==ABORTING
It's an external library and errors in external libraries are generally not very
useful for looking for internal bugs.
It would be better not to change the code and use standard suppression
techinques decribed at
https://clang.llvm.org/docs/AddressSanitizer.html#suppressing-reports-in-external-libraries,
but, unfortunaley, none of them seems to be able to suppress fatal errors in asan intself.
There isn't much difference, but in general we prefer to use the standard
functions. glibc provides reallocarray since version 2.26.
I moved explicit_bzero is configure test to the bottom, so that the two stdlib
functions are at the bottom.
