Follow-up for 381f6d4ba5.
When the function is called, the device may be already removed, and
another device has the same syspath. Such situation can occur when a
partition removed and another is created. In that case, the sysfs paths
of the removed and newly created partitions can be same, but their
devnums are different, and thus the database files corresponding to the
devices are also different.
Fixes#27981.
We use usec_t for storing time value, which is 64bit.
However, usleep() takes useconds_t that is (typically?) 32bit.
Also, usleep() may only support the range [0, 1000000].
This introduce usleep_safe() which takes usec_t.
Doesn't really matter since the two unicode symbols are supposedly
equivalent, but let's better follow the unicode recommendations to
prefer greek small letter mu, as per:
https://www.unicode.org/reports/tr25
SOCK_SEQPACKET is only supported on recent kernels. Let's add a
fallback to SOCK_STREAM if it is not supported.
To accomodate SOCK_STREAM, we also modify
pid_notify_with_fds_internal() to do sendmsg() in a loop as with
SOCK_STREAM, sendmsg() is not guaranteed to write all data in a single
syscall or fail otherwise.
This is a rework of #24764 by Cristian Rodríguez
<crodriguez@owncloud.com>, which stalled.
Instead of assigning -1 we'll use a macro defined to INT_MAX however.
After the commit 7a4ee86161,
sd_journal_next() following sd_journal_seek_tail() takes no-op,
and we need to call sd_journal_previous(). This may be useful in
some cases, e.g. to fix the issue explained in the previous commit.
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.
Luca Boccassi
Yu Watanabe
Frantisek Sumsal
Zbigniew Jędrzejewski-Szmek
Ronan Pigott
Lennart Poettering
Frantisek Sumsal
licunlong
Daan De Meyer
Nick Rosbrook
Thorsten Kukuk
David Tardon