diff options
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/Kconfig | 9 | ||||
| -rw-r--r-- | samples/Makefile | 2 | ||||
| -rw-r--r-- | samples/kobject/kset-example.c | 3 | ||||
| -rw-r--r-- | samples/pidfd/Makefile | 6 | ||||
| -rw-r--r-- | samples/pidfd/pidfd-metadata.c | 112 | ||||
| -rw-r--r-- | samples/vfs/Makefile (renamed from samples/statx/Makefile) | 5 | ||||
| -rw-r--r-- | samples/vfs/test-fsmount.c | 133 | ||||
| -rw-r--r-- | samples/vfs/test-statx.c (renamed from samples/statx/test-statx.c) | 11 |
8 files changed, 273 insertions, 8 deletions
diff --git a/samples/Kconfig b/samples/Kconfig index d19754ccad08..30a89425009c 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -154,10 +154,11 @@ config SAMPLE_ANDROID_BINDERFS 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 +config SAMPLE_VFS + bool "Build example programs that use new VFS system calls" help - Build example userspace program to use the new extended-stat syscall. + Build example userspace programs that use new VFS system calls such + as mount API and statx(). Note that this is restricted to the x86 + arch whilst it accesses system calls that aren't yet in all arches. endif # SAMPLES diff --git a/samples/Makefile b/samples/Makefile index b1142a958811..2484cc262d3e 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/ binderfs/ + vfio-mdev/ vfs/ qmi/ binderfs/ pidfd/ diff --git a/samples/kobject/kset-example.c b/samples/kobject/kset-example.c index 401328fd687d..c8010f126808 100644 --- a/samples/kobject/kset-example.c +++ b/samples/kobject/kset-example.c @@ -178,6 +178,7 @@ static struct attribute *foo_default_attrs[] = { &bar_attribute.attr, NULL, /* need to NULL terminate the list of attributes */ }; +ATTRIBUTE_GROUPS(foo_default); /* * Our own ktype for our kobjects. Here we specify our sysfs ops, the @@ -187,7 +188,7 @@ static struct attribute *foo_default_attrs[] = { static struct kobj_type foo_ktype = { .sysfs_ops = &foo_sysfs_ops, .release = foo_release, - .default_attrs = foo_default_attrs, + .default_groups = foo_default_groups, }; static struct kset *example_kset; diff --git a/samples/pidfd/Makefile b/samples/pidfd/Makefile new file mode 100644 index 000000000000..0ff97784177a --- /dev/null +++ b/samples/pidfd/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 + +hostprogs-y := pidfd-metadata +always := $(hostprogs-y) +HOSTCFLAGS_pidfd-metadata.o += -I$(objtree)/usr/include +all: pidfd-metadata diff --git a/samples/pidfd/pidfd-metadata.c b/samples/pidfd/pidfd-metadata.c new file mode 100644 index 000000000000..640f5f757c57 --- /dev/null +++ b/samples/pidfd/pidfd-metadata.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <inttypes.h> +#include <limits.h> +#include <sched.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/syscall.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#ifndef CLONE_PIDFD +#define CLONE_PIDFD 0x00001000 +#endif + +static int do_child(void *args) +{ + printf("%d\n", getpid()); + _exit(EXIT_SUCCESS); +} + +static pid_t pidfd_clone(int flags, int *pidfd) +{ + size_t stack_size = 1024; + char *stack[1024] = { 0 }; + +#ifdef __ia64__ + return __clone2(do_child, stack, stack_size, flags | SIGCHLD, NULL, pidfd); +#else + return clone(do_child, stack + stack_size, flags | SIGCHLD, NULL, pidfd); +#endif +} + +static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, + unsigned int flags) +{ + return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); +} + +static int pidfd_metadata_fd(pid_t pid, int pidfd) +{ + int procfd, ret; + char path[100]; + + snprintf(path, sizeof(path), "/proc/%d", pid); + procfd = open(path, O_DIRECTORY | O_RDONLY | O_CLOEXEC); + if (procfd < 0) { + warn("Failed to open %s\n", path); + return -1; + } + + /* + * Verify that the pid has not been recycled and our /proc/<pid> handle + * is still valid. + */ + ret = sys_pidfd_send_signal(pidfd, 0, NULL, 0); + if (ret < 0) { + switch (errno) { + case EPERM: + /* Process exists, just not allowed to signal it. */ + break; + default: + warn("Failed to signal process\n"); + close(procfd); + procfd = -1; + } + } + + return procfd; +} + +int main(int argc, char *argv[]) +{ + int pidfd = 0, ret = EXIT_FAILURE; + char buf[4096] = { 0 }; + pid_t pid; + int procfd, statusfd; + ssize_t bytes; + + pid = pidfd_clone(CLONE_PIDFD, &pidfd); + if (pid < 0) + exit(ret); + + procfd = pidfd_metadata_fd(pid, pidfd); + close(pidfd); + if (procfd < 0) + goto out; + + statusfd = openat(procfd, "status", O_RDONLY | O_CLOEXEC); + close(procfd); + if (statusfd < 0) + goto out; + + bytes = read(statusfd, buf, sizeof(buf)); + if (bytes > 0) + bytes = write(STDOUT_FILENO, buf, bytes); + close(statusfd); + ret = EXIT_SUCCESS; + +out: + (void)wait(NULL); + + exit(ret); +} diff --git a/samples/statx/Makefile b/samples/vfs/Makefile index 59df7c25a9d1..4ac9690fb3c4 100644 --- a/samples/statx/Makefile +++ b/samples/vfs/Makefile @@ -1,7 +1,10 @@ # List of programs to build -hostprogs-$(CONFIG_SAMPLE_STATX) := test-statx +hostprogs-$(CONFIG_SAMPLE_VFS) := \ + test-fsmount \ + test-statx # Tell kbuild to always build the programs always := $(hostprogs-y) +HOSTCFLAGS_test-fsmount.o += -I$(objtree)/usr/include HOSTCFLAGS_test-statx.o += -I$(objtree)/usr/include diff --git a/samples/vfs/test-fsmount.c b/samples/vfs/test-fsmount.c new file mode 100644 index 000000000000..266d72b3dce4 --- /dev/null +++ b/samples/vfs/test-fsmount.c @@ -0,0 +1,133 @@ +/* fd-based mount test. + * + * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <sys/prctl.h> +#include <sys/wait.h> +#include <linux/mount.h> +#include <linux/unistd.h> + +#define E(x) do { if ((x) == -1) { perror(#x); exit(1); } } while(0) + +static void check_messages(int fd) +{ + char buf[4096]; + int err, n; + + err = errno; + + for (;;) { + n = read(fd, buf, sizeof(buf)); + if (n < 0) + break; + n -= 2; + + switch (buf[0]) { + case 'e': + fprintf(stderr, "Error: %*.*s\n", n, n, buf + 2); + break; + case 'w': + fprintf(stderr, "Warning: %*.*s\n", n, n, buf + 2); + break; + case 'i': + fprintf(stderr, "Info: %*.*s\n", n, n, buf + 2); + break; + } + } + + errno = err; +} + +static __attribute__((noreturn)) +void mount_error(int fd, const char *s) +{ + check_messages(fd); + fprintf(stderr, "%s: %m\n", s); + exit(1); +} + +/* Hope -1 isn't a syscall */ +#ifndef __NR_fsopen +#define __NR_fsopen -1 +#endif +#ifndef __NR_fsmount +#define __NR_fsmount -1 +#endif +#ifndef __NR_fsconfig +#define __NR_fsconfig -1 +#endif +#ifndef __NR_move_mount +#define __NR_move_mount -1 +#endif + + +static inline int fsopen(const char *fs_name, unsigned int flags) +{ + return syscall(__NR_fsopen, fs_name, flags); +} + +static inline int fsmount(int fsfd, unsigned int flags, unsigned int ms_flags) +{ + return syscall(__NR_fsmount, fsfd, flags, ms_flags); +} + +static inline int fsconfig(int fsfd, unsigned int cmd, + const char *key, const void *val, int aux) +{ + return syscall(__NR_fsconfig, fsfd, cmd, key, val, aux); +} + +static inline int move_mount(int from_dfd, const char *from_pathname, + int to_dfd, const char *to_pathname, + unsigned int flags) +{ + return syscall(__NR_move_mount, + from_dfd, from_pathname, + to_dfd, to_pathname, flags); +} + +#define E_fsconfig(fd, cmd, key, val, aux) \ + do { \ + if (fsconfig(fd, cmd, key, val, aux) == -1) \ + mount_error(fd, key ?: "create"); \ + } while (0) + +int main(int argc, char *argv[]) +{ + int fsfd, mfd; + + /* Mount a publically available AFS filesystem */ + fsfd = fsopen("afs", 0); + if (fsfd == -1) { + perror("fsopen"); + exit(1); + } + + E_fsconfig(fsfd, FSCONFIG_SET_STRING, "source", "#grand.central.org:root.cell.", 0); + E_fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0); + + mfd = fsmount(fsfd, 0, MOUNT_ATTR_RDONLY); + if (mfd < 0) + mount_error(fsfd, "fsmount"); + E(close(fsfd)); + + if (move_mount(mfd, "", AT_FDCWD, "/mnt", MOVE_MOUNT_F_EMPTY_PATH) < 0) { + perror("move_mount"); + exit(1); + } + + E(close(mfd)); + exit(0); +} diff --git a/samples/statx/test-statx.c b/samples/vfs/test-statx.c index d4d77b09412c..e91f918e84c4 100644 --- a/samples/statx/test-statx.c +++ b/samples/vfs/test-statx.c @@ -25,13 +25,21 @@ #include <sys/types.h> #include <linux/stat.h> #include <linux/fcntl.h> +#define statx foo +#define statx_timestamp foo_timestamp #include <sys/stat.h> +#undef statx +#undef statx_timestamp #define AT_STATX_SYNC_TYPE 0x6000 #define AT_STATX_SYNC_AS_STAT 0x0000 #define AT_STATX_FORCE_SYNC 0x2000 #define AT_STATX_DONT_SYNC 0x4000 +#ifndef __NR_statx +#define __NR_statx -1 +#endif + static __attribute__((unused)) ssize_t statx(int dfd, const char *filename, unsigned flags, unsigned int mask, struct statx *buffer) @@ -157,7 +165,8 @@ static void dump_statx(struct statx *stx) "?dai?c??" /* 7- 0 0x00000000-000000ff */ ; - printf("Attributes: %016llx (", stx->stx_attributes); + printf("Attributes: %016llx (", + (unsigned long long)stx->stx_attributes); for (byte = 64 - 8; byte >= 0; byte -= 8) { bits = stx->stx_attributes >> byte; mbits = stx->stx_attributes_mask >> byte; |