diff options
| author | Robert Morell <rmorell@nvidia.com> | 2010-11-02 10:31:31 -0700 |
|---|---|---|
| committer | Niket Sirsi <nsirsi@nvidia.com> | 2011-01-28 19:55:11 -0800 |
| commit | 9c689e66aaf955a838c7477b5671021c154ab037 (patch) | |
| tree | 58a66e0cc71833ab0dd69670a0a94d6b88b9e7cc | |
| parent | cb96d40b1a3665235a564e078a305d0e419266e1 (diff) | |
nvmap: Optionally check global list for IOC_GET_ID
For NVMAP_IOC_GET_ID, if the requested handle isn't found in the
client-private list, check the device-wide handles if allowed (global
handles or superuser).
The proper way to share memory between clients is to first call
IOC_GET_ID from the client who owns the memory, pass the resulting ID to
the new client, and then use IOC_FROM_ID in the new client to get a
handle. However, some (broken) legacy applications did both IOC_GET_ID
and IOC_FROM_ID steps in the new client. To support those applications
but hopefully prevent new applications from growing the same behavior,
the NVMAP_SEARCH_GLOBAL_HANDLES config option was added that restores
the old behavior (default N).
Note that even with this option enabled, the client issuing the
IOC_GET_ID call must be privileged to access the handle provided. In
practice, this means the global list search only works for clients who
have opened the /dev/knvmap super device node.
Change-Id: I6a4490de922864d9119b24e610cfa127ec64bdc7
Signed-off-by: Robert Morell <rmorell@nvidia.com>
Reviewed-on: http://git-master/r/14431
Reviewed-by: Niket Sirsi <nsirsi@nvidia.com>
Tested-by: Niket Sirsi <nsirsi@nvidia.com>
| -rw-r--r-- | drivers/video/tegra/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/video/tegra/nvmap/nvmap_ioctl.c | 10 |
2 files changed, 21 insertions, 0 deletions
diff --git a/drivers/video/tegra/Kconfig b/drivers/video/tegra/Kconfig index 9968738777fd..c9e5f21a69c2 100644 --- a/drivers/video/tegra/Kconfig +++ b/drivers/video/tegra/Kconfig @@ -77,5 +77,16 @@ config NVMAP_CARVEOUT_KILLER processes. This will kill the largest consumers of lowest priority first. +config NVMAP_SEARCH_GLOBAL_HANDLES + bool "Check global handle list when generating memory IDs" + depends on TEGRA_NVMAP + default n + help + Say Y here to allow the system to search through memory handles not + owned by the caller when generating a memory ID. This shouldn't be + necessary for well-written applications, but is provided for + compatibility with legacy applications. + If unsure, say N. + endif diff --git a/drivers/video/tegra/nvmap/nvmap_ioctl.c b/drivers/video/tegra/nvmap/nvmap_ioctl.c index b943065a44c0..0c772f81ffa8 100644 --- a/drivers/video/tegra/nvmap/nvmap_ioctl.c +++ b/drivers/video/tegra/nvmap/nvmap_ioctl.c @@ -143,6 +143,16 @@ int nvmap_ioctl_getid(struct file *filp, void __user *arg) h = nvmap_get_handle_id(client, op.handle); +#ifdef CONFIG_NVMAP_SEARCH_GLOBAL_HANDLES + /* + * Check for device-wide global handles. This may be needed in broken + * memory sharing scenarios when handles are passed from client to + * client instead of the memory IDs. + */ + if (!h) + h = nvmap_validate_get(client, op.handle); +#endif + if (!h) return -EPERM; |