diff options
| -rw-r--r-- | fs/userfaultfd.c | 28 | ||||
| -rw-r--r-- | include/linux/userfaultfd_k.h | 12 | ||||
| -rw-r--r-- | include/uapi/linux/userfaultfd.h | 10 | ||||
| -rw-r--r-- | mm/madvise.c | 2 |
4 files changed, 51 insertions, 1 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 5d37c37854b0..ea9008254df4 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -633,6 +633,34 @@ void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *vm_ctx, userfaultfd_event_wait_completion(ctx, &ewq); } +void madvise_userfault_dontneed(struct vm_area_struct *vma, + struct vm_area_struct **prev, + unsigned long start, unsigned long end) +{ + struct mm_struct *mm = vma->vm_mm; + struct userfaultfd_ctx *ctx; + struct userfaultfd_wait_queue ewq; + + ctx = vma->vm_userfaultfd_ctx.ctx; + if (!ctx || !(ctx->features & UFFD_FEATURE_EVENT_MADVDONTNEED)) + return; + + userfaultfd_ctx_get(ctx); + up_read(&mm->mmap_sem); + + *prev = NULL; /* We wait for ACK w/o the mmap semaphore */ + + msg_init(&ewq.msg); + + ewq.msg.event = UFFD_EVENT_MADVDONTNEED; + ewq.msg.arg.madv_dn.start = start; + ewq.msg.arg.madv_dn.end = end; + + userfaultfd_event_wait_completion(ctx, &ewq); + + down_read(&mm->mmap_sem); +} + static int userfaultfd_release(struct inode *inode, struct file *file) { struct userfaultfd_ctx *ctx = file->private_data; diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h index 78ec197e8b47..f431861f22f1 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -61,6 +61,11 @@ extern void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *, unsigned long from, unsigned long to, unsigned long len); +extern void madvise_userfault_dontneed(struct vm_area_struct *vma, + struct vm_area_struct **prev, + unsigned long start, + unsigned long end); + #else /* CONFIG_USERFAULTFD */ /* mm helpers */ @@ -106,6 +111,13 @@ static inline void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *ctx, unsigned long len) { } + +static inline void madvise_userfault_dontneed(struct vm_area_struct *vma, + struct vm_area_struct **prev, + unsigned long start, + unsigned long end) +{ +} #endif /* CONFIG_USERFAULTFD */ #endif /* _LINUX_USERFAULTFD_K_H */ diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h index 79a85e5bd388..2bbf32319cf5 100644 --- a/include/uapi/linux/userfaultfd.h +++ b/include/uapi/linux/userfaultfd.h @@ -19,7 +19,8 @@ */ #define UFFD_API ((__u64)0xAA) #define UFFD_API_FEATURES (UFFD_FEATURE_EVENT_FORK | \ - UFFD_FEATURE_EVENT_REMAP) + UFFD_FEATURE_EVENT_REMAP | \ + UFFD_FEATURE_EVENT_MADVDONTNEED) #define UFFD_API_IOCTLS \ ((__u64)1 << _UFFDIO_REGISTER | \ (__u64)1 << _UFFDIO_UNREGISTER | \ @@ -84,6 +85,11 @@ struct uffd_msg { } remap; struct { + __u64 start; + __u64 end; + } madv_dn; + + struct { /* unused reserved fields */ __u64 reserved1; __u64 reserved2; @@ -98,6 +104,7 @@ struct uffd_msg { #define UFFD_EVENT_PAGEFAULT 0x12 #define UFFD_EVENT_FORK 0x13 #define UFFD_EVENT_REMAP 0x14 +#define UFFD_EVENT_MADVDONTNEED 0x15 /* flags for UFFD_EVENT_PAGEFAULT */ #define UFFD_PAGEFAULT_FLAG_WRITE (1<<0) /* If this was a write fault */ @@ -119,6 +126,7 @@ struct uffdio_api { #define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0) #define UFFD_FEATURE_EVENT_FORK (1<<1) #define UFFD_FEATURE_EVENT_REMAP (1<<2) +#define UFFD_FEATURE_EVENT_MADVDONTNEED (1<<3) __u64 features; __u64 ioctls; diff --git a/mm/madvise.c b/mm/madvise.c index 0e3828eae9f8..06ffb5a170de 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -10,6 +10,7 @@ #include <linux/syscalls.h> #include <linux/mempolicy.h> #include <linux/page-isolation.h> +#include <linux/userfaultfd_k.h> #include <linux/hugetlb.h> #include <linux/falloc.h> #include <linux/sched.h> @@ -477,6 +478,7 @@ static long madvise_dontneed(struct vm_area_struct *vma, return -EINVAL; zap_page_range(vma, start, end - start, NULL); + madvise_userfault_dontneed(vma, prev, start, end); return 0; } |