Re: [Qemu-devel] [PATCH v2 1/2] util: Introduce qemu_get_pid_name
On Wed, Sep 21, 2016 at 01:26:02PM +0200, Michal Privoznik wrote:
> This is a small helper that tries to fetch binary name for given
> PID.
>
> Signed-off-by: Michal Privoznik
> ---
> include/qemu/osdep.h | 10 ++
> util/oslib-posix.c | 37 +
> util/oslib-win32.c | 7 +++
> 3 files changed, 54 insertions(+)
>
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index 9e9fa61..384bfe2 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -388,6 +388,16 @@ void os_mem_prealloc(int fd, char *area, size_t sz,
> Error **errp);
> int qemu_read_password(char *buf, int buf_size);
>
> /**
> + * qemu_get_pid_name:
> + * @pid: pid of a process
> + *
> + * For given @pid fetch its name. Caller is responsible for
> + * freeing the string when no longer needed.
> + * Returns allocated string on success, NULL on failure.
> + */
> +char *qemu_get_pid_name(pid_t pid);
> +
> +/**
> * qemu_fork:
> *
> * A version of fork that avoids signal handler race
> diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> index f2d4e9e..0555425 100644
> --- a/util/oslib-posix.c
> +++ b/util/oslib-posix.c
> @@ -46,6 +46,7 @@
>
> #ifdef __FreeBSD__
> #include
> +#include
> #endif
>
> #include "qemu/mmap-alloc.h"
> @@ -430,6 +431,42 @@ int qemu_read_password(char *buf, int buf_size)
> }
>
>
> +char *qemu_get_pid_name(pid_t pid)
> +{
> +char *name = NULL;
> +char *pid_path;
> +char buf[PATH_MAX];
> +size_t len;
> +
> +#if defined(__FreeBSD__)
> +/* BSDs don't have /proc, but they provide a nice substitute */
> +struct kinfo_proc *proc = kinfo_getproc(pid);
> +if (proc) {
> +name = g_strdup(proc->ki_comm);
> +free(proc);
> +}
> +#else
> +/* Assume a system with reasonable procfs */
> +FILE *f;
> +
> +pid_path = g_strdup_printf("/proc/%d/cmdline", pid);
> +f = fopen(pid_path, "r");
> +if (!f) {
> +return NULL;
> +}
> +
> +len = fread(buf, 1, sizeof(buf), f);
> +if (len) {
> +name = g_strdup(buf);
> +}
> +fclose(f);
This use of fixed length buffer and the calling of multiple stdio
functions can be replaced by g_file_get_contents() which will be
much clearer.
Regards,
Daniel
--
|: http://berrange.com -o-http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
Re: [Qemu-devel] [PATCH v2 1/2] util: Introduce qemu_get_pid_name
On 21/09/2016 13:26, Michal Privoznik wrote:
> This is a small helper that tries to fetch binary name for given
> PID.
>
> Signed-off-by: Michal Privoznik
> ---
> include/qemu/osdep.h | 10 ++
> util/oslib-posix.c | 37 +
> util/oslib-win32.c | 7 +++
> 3 files changed, 54 insertions(+)
>
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index 9e9fa61..384bfe2 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -388,6 +388,16 @@ void os_mem_prealloc(int fd, char *area, size_t sz,
> Error **errp);
> int qemu_read_password(char *buf, int buf_size);
>
> /**
> + * qemu_get_pid_name:
> + * @pid: pid of a process
> + *
> + * For given @pid fetch its name. Caller is responsible for
> + * freeing the string when no longer needed.
> + * Returns allocated string on success, NULL on failure.
> + */
> +char *qemu_get_pid_name(pid_t pid);
> +
> +/**
> * qemu_fork:
> *
> * A version of fork that avoids signal handler race
> diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> index f2d4e9e..0555425 100644
> --- a/util/oslib-posix.c
> +++ b/util/oslib-posix.c
> @@ -46,6 +46,7 @@
>
> #ifdef __FreeBSD__
> #include
> +#include
> #endif
>
> #include "qemu/mmap-alloc.h"
> @@ -430,6 +431,42 @@ int qemu_read_password(char *buf, int buf_size)
> }
>
>
> +char *qemu_get_pid_name(pid_t pid)
> +{
> +char *name = NULL;
> +char *pid_path;
> +char buf[PATH_MAX];
pid_path, buf, len should also be in the #else. I can fix that too.
Paolo
> +size_t len;
> +
> +#if defined(__FreeBSD__)
> +/* BSDs don't have /proc, but they provide a nice substitute */
> +struct kinfo_proc *proc = kinfo_getproc(pid);
> +if (proc) {
> +name = g_strdup(proc->ki_comm);
> +free(proc);
> +}
> +#else
> +/* Assume a system with reasonable procfs */
> +FILE *f;
> +
> +pid_path = g_strdup_printf("/proc/%d/cmdline", pid);
> +f = fopen(pid_path, "r");
> +if (!f) {
> +return NULL;
> +}
> +
> +len = fread(buf, 1, sizeof(buf), f);
> +if (len) {
> +name = g_strdup(buf);
> +}
> +fclose(f);
> +
> +#endif
> +
> +return name;
> +}
> +
> +
> pid_t qemu_fork(Error **errp)
> {
> sigset_t oldmask, newmask;
> diff --git a/util/oslib-win32.c b/util/oslib-win32.c
> index 4c1dcf1..d09863c 100644
> --- a/util/oslib-win32.c
> +++ b/util/oslib-win32.c
> @@ -575,6 +575,13 @@ int qemu_read_password(char *buf, int buf_size)
> }
>
>
> +char *qemu_get_pid_name(pid_t pid)
> +{
> +/* XXX Implement me */
> +abort();
> +}
> +
> +
> pid_t qemu_fork(Error **errp)
> {
> errno = ENOSYS;
>
