diff options
| -rw-r--r-- | fs/userfaultfd.c | 3 | ||||
| -rw-r--r-- | include/uapi/linux/userfaultfd.h | 10 |
2 files changed, 12 insertions, 1 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 01a85e2660b8..5fd4d846691f 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -370,6 +370,9 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason) VM_BUG_ON(reason & ~(VM_UFFD_MISSING|VM_UFFD_WP)); VM_BUG_ON(!(reason & VM_UFFD_MISSING) ^ !!(reason & VM_UFFD_WP)); + if (ctx->features & UFFD_FEATURE_SIGBUS) + goto out; + /* * If it's already released don't get it. This avoids to loop * in __get_user_pages if userfaultfd_release waits on the diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h index 3b059530dac9..d39d5db56771 100644 --- a/include/uapi/linux/userfaultfd.h +++ b/include/uapi/linux/userfaultfd.h @@ -23,7 +23,8 @@ UFFD_FEATURE_EVENT_REMOVE | \ UFFD_FEATURE_EVENT_UNMAP | \ UFFD_FEATURE_MISSING_HUGETLBFS | \ - UFFD_FEATURE_MISSING_SHMEM) + UFFD_FEATURE_MISSING_SHMEM | \ + UFFD_FEATURE_SIGBUS) #define UFFD_API_IOCTLS \ ((__u64)1 << _UFFDIO_REGISTER | \ (__u64)1 << _UFFDIO_UNREGISTER | \ @@ -153,6 +154,12 @@ struct uffdio_api { * UFFD_FEATURE_MISSING_SHMEM works the same as * UFFD_FEATURE_MISSING_HUGETLBFS, but it applies to shmem * (i.e. tmpfs and other shmem based APIs). + * + * UFFD_FEATURE_SIGBUS feature means no page-fault + * (UFFD_EVENT_PAGEFAULT) event will be delivered, instead + * a SIGBUS signal will be sent to the faulting process. + * The application process can enable this behavior by adding + * it to uffdio_api.features. */ #define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0) #define UFFD_FEATURE_EVENT_FORK (1<<1) @@ -161,6 +168,7 @@ struct uffdio_api { #define UFFD_FEATURE_MISSING_HUGETLBFS (1<<4) #define UFFD_FEATURE_MISSING_SHMEM (1<<5) #define UFFD_FEATURE_EVENT_UNMAP (1<<6) +#define UFFD_FEATURE_SIGBUS (1<<7) __u64 features; __u64 ioctls; |