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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-09 20:56:17 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-09 20:56:17 +0300 |
commit | 1a29e857507046e413ca7a4a7c9cd32fed9ea255 (patch) | |
tree | 5a46d9c4dcab39fc588a9ac2c9f5e4c866d41254 /samples | |
parent | c4703acd6d4a58dc4b31ad2a8f8b14becb898d25 (diff) | |
parent | 4064174becc09a5a2385a27c8a6fd40888b0e13c (diff) |
Merge tag 'docs-5.1' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A fairly routine cycle for docs - lots of typo fixes, some new
documents, and more translations. There's also some LICENSES
adjustments from Thomas"
* tag 'docs-5.1' of git://git.lwn.net/linux: (74 commits)
docs: Bring some order to filesystem documentation
Documentation/locking/lockdep: Drop last two chars of sample states
doc: rcu: Suspicious RCU usage is a warning
docs: driver-api: iio: fix errors in documentation
Documentation/process/howto: Update for 4.x -> 5.x versioning
docs: Explicitly state that the 'Fixes:' tag shouldn't split lines
doc: security: Add kern-doc for lsm_hooks.h
doc: sctp: Merge and clean up rst files
Docs: Correct /proc/stat path
scripts/spdxcheck.py: fix C++ comment style detection
doc: fix typos in license-rules.rst
Documentation: fix admin-guide/README.rst minimum gcc version requirement
doc: process: complete removal of info about -git patches
doc: translations: sync translations 'remove info about -git patches'
perf-security: wrap paragraphs on 72 columns
perf-security: elaborate on perf_events/Perf privileged users
perf-security: document collected perf_events/Perf data categories
perf-security: document perf_events/Perf resource control
sysfs.txt: add note on available attribute macros
docs: kernel-doc: typo "if ... if" -> "if ... is"
...
Diffstat (limited to 'samples')
-rw-r--r-- | samples/Kconfig | 7 | ||||
-rw-r--r-- | samples/Makefile | 2 | ||||
-rw-r--r-- | samples/binderfs/Makefile | 1 | ||||
-rw-r--r-- | samples/binderfs/binderfs_example.c | 83 |
4 files changed, 92 insertions, 1 deletions
diff --git a/samples/Kconfig b/samples/Kconfig index ad1ec7016d4c..d19754ccad08 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -147,6 +147,13 @@ config SAMPLE_VFIO_MDEV_MBOCHS Specifically it does *not* include any legacy vga stuff. Device looks a lot like "qemu -device secondary-vga". +config SAMPLE_ANDROID_BINDERFS + bool "Build Android binderfs example" + depends on CONFIG_ANDROID_BINDERFS + help + Builds a sample program to illustrate the use of the Android binderfs + filesystem. + config SAMPLE_STATX bool "Build example extended-stat using code" depends on BROKEN diff --git a/samples/Makefile b/samples/Makefile index bd601c038b86..b1142a958811 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -3,4 +3,4 @@ obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ trace_events/ livepatch/ \ hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \ configfs/ connector/ v4l/ trace_printk/ \ - vfio-mdev/ statx/ qmi/ + vfio-mdev/ statx/ qmi/ binderfs/ diff --git a/samples/binderfs/Makefile b/samples/binderfs/Makefile new file mode 100644 index 000000000000..01ca9f2529a7 --- /dev/null +++ b/samples/binderfs/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_SAMPLE_ANDROID_BINDERFS) += binderfs_example.o diff --git a/samples/binderfs/binderfs_example.c b/samples/binderfs/binderfs_example.c new file mode 100644 index 000000000000..5bbd2ebc0aea --- /dev/null +++ b/samples/binderfs/binderfs_example.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <sched.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/mount.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <linux/android/binder.h> +#include <linux/android/binderfs.h> + +int main(int argc, char *argv[]) +{ + int fd, ret, saved_errno; + size_t len; + struct binderfs_device device = { 0 }; + + ret = unshare(CLONE_NEWNS); + if (ret < 0) { + fprintf(stderr, "%s - Failed to unshare mount namespace\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0); + if (ret < 0) { + fprintf(stderr, "%s - Failed to mount / as private\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + ret = mkdir("/dev/binderfs", 0755); + if (ret < 0 && errno != EEXIST) { + fprintf(stderr, "%s - Failed to create binderfs mountpoint\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + ret = mount(NULL, "/dev/binderfs", "binder", 0, 0); + if (ret < 0) { + fprintf(stderr, "%s - Failed to mount binderfs\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + memcpy(device.name, "my-binder", strlen("my-binder")); + + fd = open("/dev/binderfs/binder-control", O_RDONLY | O_CLOEXEC); + if (fd < 0) { + fprintf(stderr, "%s - Failed to open binder-control device\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + ret = ioctl(fd, BINDER_CTL_ADD, &device); + saved_errno = errno; + close(fd); + errno = saved_errno; + if (ret < 0) { + fprintf(stderr, "%s - Failed to allocate new binder device\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + printf("Allocated new binder device with major %d, minor %d, and name %s\n", + device.major, device.minor, device.name); + + ret = unlink("/dev/binderfs/my-binder"); + if (ret < 0) { + fprintf(stderr, "%s - Failed to delete binder device\n", + strerror(errno)); + exit(EXIT_FAILURE); + } + + /* Cleanup happens when the mount namespace dies. */ + exit(EXIT_SUCCESS); +} |