| Message ID | 20211130033820.18235-17-laurent.pinchart@ideasonboard.com |
|---|---|
| State | New |
| Delegated to: | Laurent Pinchart |
| Headers | show |
| Series |
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| Related | show |
Hi Laurent, thank you for the patch. On Tue, Nov 30, 2021 at 12:39 PM Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > The V4L2VideoDevice::open() function that takes an open file handle > duplicates it internally, and leaves the original handle untouched. This > is documented but not enforced through language constructs. Fix it by > passing a SharedFD to the function. FileDescriptor. ditto for the commit title. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Hirokazu Honda <hiroh@chromium.org> > --- > include/libcamera/internal/v4l2_videodevice.h | 2 +- > src/libcamera/v4l2_videodevice.cpp | 22 ++++++++----------- > 2 files changed, 10 insertions(+), 14 deletions(-) > > diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h > index 80b665771782..9f556f99587c 100644 > --- a/include/libcamera/internal/v4l2_videodevice.h > +++ b/include/libcamera/internal/v4l2_videodevice.h > @@ -184,7 +184,7 @@ public: > ~V4L2VideoDevice(); > > int open(); > - int open(int handle, enum v4l2_buf_type type); > + int open(FileDescriptor handle, enum v4l2_buf_type type); > void close(); > > const char *driverName() const { return caps_.driver(); } > diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp > index 3966483a365f..5f1cc6e2f47f 100644 > --- a/src/libcamera/v4l2_videodevice.cpp > +++ b/src/libcamera/v4l2_videodevice.cpp > @@ -612,16 +612,14 @@ int V4L2VideoDevice::open() > * its type from the capabilities. This can be used to force a given device type > * for memory-to-memory devices. > * > - * The file descriptor \a handle is duplicated, and the caller is responsible > - * for closing the \a handle when it has no further use for it. The close() > - * function will close the duplicated file descriptor, leaving \a handle > - * untouched. > + * The file descriptor \a handle is duplicated, no reference to the original > + * handle is kept. > * > * \return 0 on success or a negative error code otherwise > */ > -int V4L2VideoDevice::open(int handle, enum v4l2_buf_type type) > +int V4L2VideoDevice::open(FileDescriptor handle, enum v4l2_buf_type type) > { > - UniqueFD newFd(dup(handle)); > + UniqueFD newFd = handle.dup(); > if (!newFd.isValid()) { > LOG(V4L2, Error) << "Failed to duplicate file handle: " > << strerror(errno); > @@ -1900,12 +1898,10 @@ int V4L2M2MDevice::open() > > /* > * The output and capture V4L2VideoDevice instances use the same file > - * handle for the same device node. The local file handle can be closed > - * as the V4L2VideoDevice::open() retains a handle by duplicating the > - * fd passed in. > + * handle for the same device node. > */ > - UniqueFD fd(syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(), > - O_RDWR | O_NONBLOCK)); > + FileDescriptor fd(syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(), > + O_RDWR | O_NONBLOCK)); > if (!fd.isValid()) { > ret = -errno; > LOG(V4L2, Error) << "Failed to open V4L2 M2M device: " > @@ -1913,11 +1909,11 @@ int V4L2M2MDevice::open() > return ret; > } > > - ret = output_->open(fd.get(), V4L2_BUF_TYPE_VIDEO_OUTPUT); > + ret = output_->open(fd, V4L2_BUF_TYPE_VIDEO_OUTPUT); > if (ret) > goto err; > > - ret = capture_->open(fd.get(), V4L2_BUF_TYPE_VIDEO_CAPTURE); > + ret = capture_->open(fd, V4L2_BUF_TYPE_VIDEO_CAPTURE); > if (ret) > goto err; > > -- > Regards, > > Laurent Pinchart >
Hi Laurent On Tue, Nov 30, 2021 at 05:38:14AM +0200, Laurent Pinchart wrote: > The V4L2VideoDevice::open() function that takes an open file handle > duplicates it internally, and leaves the original handle untouched. This > is documented but not enforced through language constructs. Fix it by > passing a SharedFD to the function. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> With Hiro comments addressed Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Thanks j > --- > include/libcamera/internal/v4l2_videodevice.h | 2 +- > src/libcamera/v4l2_videodevice.cpp | 22 ++++++++----------- > 2 files changed, 10 insertions(+), 14 deletions(-) > > diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h > index 80b665771782..9f556f99587c 100644 > --- a/include/libcamera/internal/v4l2_videodevice.h > +++ b/include/libcamera/internal/v4l2_videodevice.h > @@ -184,7 +184,7 @@ public: > ~V4L2VideoDevice(); > > int open(); > - int open(int handle, enum v4l2_buf_type type); > + int open(FileDescriptor handle, enum v4l2_buf_type type); > void close(); > > const char *driverName() const { return caps_.driver(); } > diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp > index 3966483a365f..5f1cc6e2f47f 100644 > --- a/src/libcamera/v4l2_videodevice.cpp > +++ b/src/libcamera/v4l2_videodevice.cpp > @@ -612,16 +612,14 @@ int V4L2VideoDevice::open() > * its type from the capabilities. This can be used to force a given device type > * for memory-to-memory devices. > * > - * The file descriptor \a handle is duplicated, and the caller is responsible > - * for closing the \a handle when it has no further use for it. The close() > - * function will close the duplicated file descriptor, leaving \a handle > - * untouched. > + * The file descriptor \a handle is duplicated, no reference to the original > + * handle is kept. > * > * \return 0 on success or a negative error code otherwise > */ > -int V4L2VideoDevice::open(int handle, enum v4l2_buf_type type) > +int V4L2VideoDevice::open(FileDescriptor handle, enum v4l2_buf_type type) > { > - UniqueFD newFd(dup(handle)); > + UniqueFD newFd = handle.dup(); > if (!newFd.isValid()) { > LOG(V4L2, Error) << "Failed to duplicate file handle: " > << strerror(errno); > @@ -1900,12 +1898,10 @@ int V4L2M2MDevice::open() > > /* > * The output and capture V4L2VideoDevice instances use the same file > - * handle for the same device node. The local file handle can be closed > - * as the V4L2VideoDevice::open() retains a handle by duplicating the > - * fd passed in. > + * handle for the same device node. > */ > - UniqueFD fd(syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(), > - O_RDWR | O_NONBLOCK)); > + FileDescriptor fd(syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(), > + O_RDWR | O_NONBLOCK)); > if (!fd.isValid()) { > ret = -errno; > LOG(V4L2, Error) << "Failed to open V4L2 M2M device: " > @@ -1913,11 +1909,11 @@ int V4L2M2MDevice::open() > return ret; > } > > - ret = output_->open(fd.get(), V4L2_BUF_TYPE_VIDEO_OUTPUT); > + ret = output_->open(fd, V4L2_BUF_TYPE_VIDEO_OUTPUT); > if (ret) > goto err; > > - ret = capture_->open(fd.get(), V4L2_BUF_TYPE_VIDEO_CAPTURE); > + ret = capture_->open(fd, V4L2_BUF_TYPE_VIDEO_CAPTURE); > if (ret) > goto err; > > -- > Regards, > > Laurent Pinchart >
diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h index 80b665771782..9f556f99587c 100644 --- a/include/libcamera/internal/v4l2_videodevice.h +++ b/include/libcamera/internal/v4l2_videodevice.h @@ -184,7 +184,7 @@ public: ~V4L2VideoDevice(); int open(); - int open(int handle, enum v4l2_buf_type type); + int open(FileDescriptor handle, enum v4l2_buf_type type); void close(); const char *driverName() const { return caps_.driver(); } diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp index 3966483a365f..5f1cc6e2f47f 100644 --- a/src/libcamera/v4l2_videodevice.cpp +++ b/src/libcamera/v4l2_videodevice.cpp @@ -612,16 +612,14 @@ int V4L2VideoDevice::open() * its type from the capabilities. This can be used to force a given device type * for memory-to-memory devices. * - * The file descriptor \a handle is duplicated, and the caller is responsible - * for closing the \a handle when it has no further use for it. The close() - * function will close the duplicated file descriptor, leaving \a handle - * untouched. + * The file descriptor \a handle is duplicated, no reference to the original + * handle is kept. * * \return 0 on success or a negative error code otherwise */ -int V4L2VideoDevice::open(int handle, enum v4l2_buf_type type) +int V4L2VideoDevice::open(FileDescriptor handle, enum v4l2_buf_type type) { - UniqueFD newFd(dup(handle)); + UniqueFD newFd = handle.dup(); if (!newFd.isValid()) { LOG(V4L2, Error) << "Failed to duplicate file handle: " << strerror(errno); @@ -1900,12 +1898,10 @@ int V4L2M2MDevice::open() /* * The output and capture V4L2VideoDevice instances use the same file - * handle for the same device node. The local file handle can be closed - * as the V4L2VideoDevice::open() retains a handle by duplicating the - * fd passed in. + * handle for the same device node. */ - UniqueFD fd(syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(), - O_RDWR | O_NONBLOCK)); + FileDescriptor fd(syscall(SYS_openat, AT_FDCWD, deviceNode_.c_str(), + O_RDWR | O_NONBLOCK)); if (!fd.isValid()) { ret = -errno; LOG(V4L2, Error) << "Failed to open V4L2 M2M device: " @@ -1913,11 +1909,11 @@ int V4L2M2MDevice::open() return ret; } - ret = output_->open(fd.get(), V4L2_BUF_TYPE_VIDEO_OUTPUT); + ret = output_->open(fd, V4L2_BUF_TYPE_VIDEO_OUTPUT); if (ret) goto err; - ret = capture_->open(fd.get(), V4L2_BUF_TYPE_VIDEO_CAPTURE); + ret = capture_->open(fd, V4L2_BUF_TYPE_VIDEO_CAPTURE); if (ret) goto err;
The V4L2VideoDevice::open() function that takes an open file handle duplicates it internally, and leaves the original handle untouched. This is documented but not enforced through language constructs. Fix it by passing a SharedFD to the function. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> --- include/libcamera/internal/v4l2_videodevice.h | 2 +- src/libcamera/v4l2_videodevice.cpp | 22 ++++++++----------- 2 files changed, 10 insertions(+), 14 deletions(-)