Commit Graph

3 Commits

Author SHA1 Message Date
Eric Blake 474a6e64f2 tools: Fix use of fcntl(F_SETFD) during socket activation
Blindly setting FD_CLOEXEC without a read-modify-write will
inadvertently clear any other intentionally-set bits, such as a
proposed new bit for designating a fd that must behave in 32-bit mode.
However, we cannot use our wrapper qemu_set_cloexec(), because that
wrapper intentionally abort()s on failure, whereas the probe here
intentionally tolerates failure to deal with incorrect socket
activation gracefully.  Instead, fix the code to do the proper
read-modify-write.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200420175309.75894-3-eblake@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
2020-05-04 14:54:35 -05:00
Thomas Huth 372a87a1d9 Do not use %m in common code to print error messages
The %m format specifier is an extension from glibc - and when compiling
QEMU for NetBSD, the compiler correctly complains, e.g.:

/home/qemu/qemu-test.ELjfrQ/src/util/main-loop.c: In function 'sigfd_handler':
/home/qemu/qemu-test.ELjfrQ/src/util/main-loop.c:64:13: warning: %m is only
 allowed in syslog(3) like functions [-Wformat=]
             printf("read from sigfd returned %zd: %m\n", len);
             ^
Let's use g_strerror() here instead, which is an easy-to-use wrapper
around the thread-safe strerror_r() function.

While we're at it, also convert the "printf()" in main-loop.c into
the preferred "error_report()".

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20191018130716.25438-1-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-22 09:38:42 +02:00
Paolo Bonzini 53fabd4b86 qemu-ga: obey LISTEN_PID when using systemd socket activation
qemu-ga's socket activation support was not obeying the LISTEN_PID
environment variable, which avoids that a process uses a socket-activation
file descriptor meant for its parent.

Mess can for example ensue if a process forks a children before consuming
the socket-activation file descriptor and therefore setting O_CLOEXEC
on it.

Luckily, qemu-nbd also got socket activation code, and its copy does
support LISTEN_PID.  Some extra fixups are needed to ensure that the
code can be used for both, but that's what this patch does.  The
main change is to replace get_listen_fds's "consume" argument with
the FIRST_SOCKET_ACTIVATION_FD macro from the qemu-nbd code.

Cc: "Richard W.M. Jones" <rjones@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-19 11:12:12 +01:00