diff options
| -rw-r--r-- | fs/pidfs.c | 17 | ||||
| -rw-r--r-- | include/uapi/linux/pidfd.h | 3 |
2 files changed, 19 insertions, 1 deletions
diff --git a/fs/pidfs.c b/fs/pidfs.c index 7e4d90cc74ff..204ebd32791a 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -293,6 +293,14 @@ static __u32 pidfs_coredump_mask(unsigned long mm_flags) return 0; } +/* This must be updated whenever a new flag is added */ +#define PIDFD_INFO_SUPPORTED (PIDFD_INFO_PID | \ + PIDFD_INFO_CREDS | \ + PIDFD_INFO_CGROUPID | \ + PIDFD_INFO_EXIT | \ + PIDFD_INFO_COREDUMP | \ + PIDFD_INFO_SUPPORTED_MASK) + static long pidfd_info(struct file *file, unsigned int cmd, unsigned long arg) { struct pidfd_info __user *uinfo = (struct pidfd_info __user *)arg; @@ -306,7 +314,7 @@ static long pidfd_info(struct file *file, unsigned int cmd, unsigned long arg) const struct cred *c; __u64 mask; - BUILD_BUG_ON(sizeof(struct pidfd_info) != PIDFD_INFO_SIZE_VER1); + BUILD_BUG_ON(sizeof(struct pidfd_info) != PIDFD_INFO_SIZE_VER2); if (!uinfo) return -EINVAL; @@ -412,6 +420,13 @@ static long pidfd_info(struct file *file, unsigned int cmd, unsigned long arg) return -ESRCH; copy_out: + if (mask & PIDFD_INFO_SUPPORTED_MASK) { + kinfo.mask |= PIDFD_INFO_SUPPORTED_MASK; + kinfo.supported_mask = PIDFD_INFO_SUPPORTED; + } + + /* Are there bits in the return mask not present in PIDFD_INFO_SUPPORTED? */ + WARN_ON_ONCE(~PIDFD_INFO_SUPPORTED & kinfo.mask); /* * If userspace and the kernel have the same struct size it can just * be copied. If userspace provides an older struct, only the bits that diff --git a/include/uapi/linux/pidfd.h b/include/uapi/linux/pidfd.h index 6ccbabd9a68d..e05caa0e00fe 100644 --- a/include/uapi/linux/pidfd.h +++ b/include/uapi/linux/pidfd.h @@ -26,9 +26,11 @@ #define PIDFD_INFO_CGROUPID (1UL << 2) /* Always returned if available, even if not requested */ #define PIDFD_INFO_EXIT (1UL << 3) /* Only returned if requested. */ #define PIDFD_INFO_COREDUMP (1UL << 4) /* Only returned if requested. */ +#define PIDFD_INFO_SUPPORTED_MASK (1UL << 5) /* Want/got supported mask flags */ #define PIDFD_INFO_SIZE_VER0 64 /* sizeof first published struct */ #define PIDFD_INFO_SIZE_VER1 72 /* sizeof second published struct */ +#define PIDFD_INFO_SIZE_VER2 80 /* sizeof third published struct */ /* * Values for @coredump_mask in pidfd_info. @@ -94,6 +96,7 @@ struct pidfd_info { __s32 exit_code; __u32 coredump_mask; __u32 __spare1; + __u64 supported_mask; /* Mask flags that this kernel supports */ }; #define PIDFS_IOCTL_MAGIC 0xFF |