When there is no matching entry stored in journal, then initial call of
`sd_journal_previous()` following `sd_journal_seek_tail()` returns
zero, and does not move the read pointer.
In the main loop, on every journal event, we call `sd_journal_next()`,
even though the current location is tail, and it takes no effect.
In such a case, we need to call `sd_journal_previous()` instead of
`sd_journal_next()`.
Previously, get_boots() used for three ways; finding boot entry by
boot ID, finding boot entry by offset, listing up all boot IDs.
Let's split it into three for each usecase.
No functional change, just refactoring.
When closing the FILE handle attached to a memstream, it may attempt to
do a realloc() that may fail during OOM situations, in which case we are
left with the buffer pointer pointing to NULL and buffer size > 0. For
example:
```
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
void *realloc(void *ptr, size_t size) {
return NULL;
}
int main(int argc, char *argv[])
{
FILE *f;
char *buf;
size_t sz = 0;
f = open_memstream(&buf, &sz);
if (!f)
return -ENOMEM;
fputs("Hello", f);
fflush(f);
printf("buf: 0x%lx, sz: %lu, errno: %d\n",
(unsigned long) buf, sz, errno);
fclose(f);
printf("buf: 0x%lx, sz: %lu, errno: %d\n",
(unsigned long) buf, sz, errno);
return 0;
}
```
```
$ gcc -o main main.c
$ ./main
buf: 0x74d4a0, sz: 5, errno: 0
buf: 0x0, sz: 5, errno: 0
```
This might do unexpected things if the underlying code expects a valid
pointer to the memstream buffer after closing the handle.
Found by Nallocfuzz.
Set --boot with --follow only if it's not already set and if --merge is
not used, since it's not compatible with --boot.
Follow-up to 2dd9285bac.
Resolves: #24565
Let's use the same common directory as the unit logic uses.
This means we have less to clean up, and opens the door to eventually
allow unprivileged operation of the
mount_image_privately_interactively() logic.
Follow-up for #25147 (db4691961c)
--follow sets arg_lines to 10, which breaks
--grep as the latter implies --reverse.
So let's not set --reverse if --follow is used.
Chasing symlinks is a core function that's used in a lot of places
so it deservers a less verbose names so let's rename it to chase()
and chaseat().
We also slightly change the pattern used for the chaseat() helpers
so we get chase_and_openat() and similar.
This is a follow-up for #26669 (81fb5375b3).
After the mentioned commit, we stopped checking if the
entry is within the range of --until if --lines is used.
However, when --since, --until and --lines=N are used
altogether, and the number of lines between --since
and --until is smaller than N, we would seek to --since
later (f582695107).
This breaks the assumption that if --lines is set,
the boundary is never exceeded because the counter of
outputs gets us covered.
Before this commit, if --since is used with --lines=N,
we seek to the place of --since and search afterwards
there, resulting in outputing the first N lines.
After this commit, we only do the above if --since is used without
--reverse and --lines. Otherwise we seek to the tail first and check
if the entry is within the range of --since later.
Before this commit, when --lines is specified, we jump to the tail and
search afterwards from there, thus breaking --until if used together.
After this commit:
If both --until and any of --reverse and --lines is specified, things get
a little tricky. We seek to the place of --until first. If only --reverse or
--reverse and --lines is specified, we search backwards and let the output
counter handle --lines for us. If only --lines is used, we just jump backwards
arg_lines and search afterwards from there.
Previously, we skip the entries before arg_lines
unconditionally, which doesn't behave correctly
when used with --grep. After this commit, when
a pattern is specified, we don't skip the entries
early, but rely on the count of the lines shown
to tell us when to stop. To achieve that we would
have to search backwards instead.
Fixes#25147
In journalctl we don't run the static destructors defined via
the STATIC_DESTRUCTOR_REGISTER() macro, since it requires a corresponding
static_destruct() call. In most cases this is handled by
the DEFINE_(TEST_)?MAIN*() macros, but journalctl defines its own main
function, so let's handle that as well.
$ valgrind --suppressions=valgrind.supp --show-leak-kinds=all --leak-check=full build/journalctl --no-pager -u system.slice -n 10 >/dev/null
==2778093== Memcheck, a memory error detector
==2778093== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al.
==2778093== Using Valgrind-3.19.0 and LibVEX; rerun with -h for copyright info
==2778093== Command: build/journalctl --no-pager -u system.slice -n 10
==2778093==
==2778093==
==2778093== HEAP SUMMARY:
==2778093== in use at exit: 8,221 bytes in 4 blocks
==2778093== total heap usage: 458 allocs, 454 frees, 255,182 bytes allocated
==2778093==
==2778093== 13 bytes in 1 blocks are still reachable in loss record 1 of 4
==2778093== at 0x484586F: malloc (vg_replace_malloc.c:381)
==2778093== by 0x4DA256D: strdup (strdup.c:42)
==2778093== by 0x4ADB747: strv_extend_with_size (strv.c:544)
==2778093== by 0x405386: strv_extend (strv.h:45)
==2778093== by 0x40816F: parse_argv (journalctl.c:933)
==2778093== by 0x40EAB5: main (journalctl.c:2111)
==2778093==
==2778093== 16 bytes in 1 blocks are still reachable in loss record 2 of 4
==2778093== at 0x484578A: malloc (vg_replace_malloc.c:380)
==2778093== by 0x484A70B: realloc (vg_replace_malloc.c:1437)
==2778093== by 0x4ADB2A3: strv_push_with_size (strv.c:423)
==2778093== by 0x4ADB620: strv_consume_with_size (strv.c:496)
==2778093== by 0x4ADB770: strv_extend_with_size (strv.c:548)
==2778093== by 0x405386: strv_extend (strv.h:45)
==2778093== by 0x40816F: parse_argv (journalctl.c:933)
==2778093== by 0x40EAB5: main (journalctl.c:2111)
==2778093==
==2778093== LEAK SUMMARY:
==2778093== definitely lost: 0 bytes in 0 blocks
==2778093== indirectly lost: 0 bytes in 0 blocks
==2778093== possibly lost: 0 bytes in 0 blocks
==2778093== still reachable: 29 bytes in 2 blocks
==2778093== suppressed: 8,192 bytes in 2 blocks
==2778093==
==2778093== For lists of detected and suppressed errors, rerun with: -s
==2778093== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
If output fields are specified, let's store this in a Set right-away,
instead of converting between strv and Set again and again for each
line.
This is not only faster, but also simpler and shorter.
-1 was used everywhere, but -EBADF or -EBADFD started being used in various
places. Let's make things consistent in the new style.
Note that there are two candidates:
EBADF 9 Bad file descriptor
EBADFD 77 File descriptor in bad state
Since we're initializating the fd, we're just assigning a value that means
"no fd yet", so it's just a bad file descriptor, and the first errno fits
better. If instead we had a valid file descriptor that became invalid because
of some operation or state change, the other errno would fit better.
In some places, initialization is dropped if unnecessary.
The name "def.h" originates from before the rule of "no needless abbreviations"
was established. Let's rename the file to clarify that it contains a collection
of various semi-related constants.
So far the --help text and the man page of journactl were mostly a large
pile of options shown next to each other. Let's add some basic
structure, and group switches by sections such as "Filtering Options",
"Output Options" and so on.
Do this the same way in the --help text and in the man page.
Since this moves everything around anyway, I also opted to rebreak all
paragraphs in the man page. This makes the patch larger than necessary,
but given that this whole patch doesn't really change contents besides
section titles I figured this would be OK.
To avoid having "#if HAVE_PCRE2" all throughout the code, let's
confine the pcre2 header specific stuff to pcre2-util.c. Instead of
exposing all the individual symbols from pcre2, let's only expose
three high level functions that do all we need:
- pcre2_pattern_compile(): Compile the regex
- pcre2_pattern_matches(): Check if the compiled regex matches a message
- pcre2_pattern_free(): Free the compiled regex
We expose the compiled pcre2 pattern (which is of type pcre2_code *) as
a void pointer to avoid having to include pcre2.h in all code where we
work with compiled pcre2 patterns. For readability, we typedef void
to pcre2_pattern and use that as the type specifier for compiled pcre2
patterns.
In function 'sd_id128_equal',
inlined from 'journal_file_verify' at ../src/libsystemd/sd-journal/journal-verify.c:1047:29:
../src/systemd/sd-id128.h:119:43: error: 'entry_boot_id.qwords[0]' may be used uninitialized [-Werror=maybe-uninitialized]
119 | return a.qwords[0] == b.qwords[0] && a.qwords[1] == b.qwords[1];
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../src/libsystemd/sd-journal/journal-verify.c: In function 'journal_file_verify':
../src/libsystemd/sd-journal/journal-verify.c:823:20: note: 'entry_boot_id.qwords[0]' was declared here
823 | sd_id128_t entry_boot_id;
| ^~~~~~~~~~~~~
cc1: all warnings being treated as errors
entry_boot_id is only used when entry_monotonic_set has been set, and that's
only done in one place where entry_boot_id is also initalized.
We already store the dlopen() stuff for other libraries in util headers
as well so let's do the same for pcre2. We also move the definition of
some trivial cleanup functions from journalctl.c to pcre2-util.h
We currently have a convoluted and complex selection of which random
numbers to use. We can simplify this down to two functions that cover
all of our use cases:
1) Randomness for crypto: this one needs to wait until the RNG is
initialized. So it uses getrandom(0). If that's not available, it
polls on /dev/random, and then reads from /dev/urandom. This function
returns whether or not it was successful, as before.
2) Randomness for other things: this one uses getrandom(GRND_INSECURE).
If it's not available it uses getrandom(GRND_NONBLOCK). And if that
would block, then it falls back to /dev/urandom. And if /dev/urandom
isn't available, it uses the fallback code. It never fails and
doesn't return a value.
These two cases match all the uses of randomness inside of systemd.
I would prefer to make both of these return void, and get rid of the
fallback code, and simply assert in the incredibly unlikely case that
/dev/urandom doesn't exist. But Luca disagrees, so this commit attempts
to instead keep case (1) returning a return value, which all the callers
already check, and fix the fallback code in (2) to be less bad than
before.
For the less bad fallback code for (2), we now use auxval and some
timestamps, together with various counters representing the invocation,
hash it all together and provide the output. Provided that AT_RANDOM is
secure, this construction is probably okay too, though notably it
doesn't have any forward secrecy. Fortunately, it's only used by
random_bytes() and not by crypto_random_bytes().
Yu Watanabe
Lennart Poettering
zhmylove
Frantisek Sumsal
David Tardon
Mike Yuan
Daan De Meyer
Zbigniew Jędrzejewski-Szmek
Daniel Braunwarth
Quentin Deslandes
Jason A. Donenfeld