diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/aio.c | 35 | ||||
| -rw-r--r-- | fs/coredump.c | 45 |
2 files changed, 64 insertions, 16 deletions
@@ -589,8 +589,8 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events) void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel) { - struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, rw); - struct kioctx *ctx = req->ki_ctx; + struct aio_kiocb *req; + struct kioctx *ctx; unsigned long flags; /* @@ -600,9 +600,13 @@ void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel) if (!(iocb->ki_flags & IOCB_AIO_RW)) return; + req = container_of(iocb, struct aio_kiocb, rw); + if (WARN_ON_ONCE(!list_empty(&req->ki_list))) return; + ctx = req->ki_ctx; + spin_lock_irqsave(&ctx->ctx_lock, flags); list_add_tail(&req->ki_list, &ctx->active_reqs); req->ki_cancel = cancel; @@ -2165,11 +2169,14 @@ COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id, #endif /* sys_io_cancel: - * Attempts to cancel an iocb previously passed to io_submit(). If the - * operation is successfully cancelled 0 is returned. May fail with - * -EFAULT if any of the data structures pointed to are invalid. May - * fail with -EINVAL if aio_context specified by ctx_id is invalid. Will - * fail with -ENOSYS if not implemented. + * Attempts to cancel an iocb previously passed to io_submit. If + * the operation is successfully cancelled, the resulting event is + * copied into the memory pointed to by result without being placed + * into the completion queue and 0 is returned. May fail with + * -EFAULT if any of the data structures pointed to are invalid. + * May fail with -EINVAL if aio_context specified by ctx_id is + * invalid. May fail with -EAGAIN if the iocb specified was not + * cancelled. Will fail with -ENOSYS if not implemented. */ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, struct io_event __user *, result) @@ -2200,12 +2207,14 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb, } spin_unlock_irq(&ctx->ctx_lock); - /* - * The result argument is no longer used - the io_event is always - * delivered via the ring buffer. - */ - if (ret == 0 && kiocb->rw.ki_flags & IOCB_AIO_RW) - aio_complete_rw(&kiocb->rw, -EINTR); + if (!ret) { + /* + * The result argument is no longer used - the io_event is + * always delivered via the ring buffer. -EINPROGRESS indicates + * cancellation is progress: + */ + ret = -EINPROGRESS; + } percpu_ref_put(&ctx->users); diff --git a/fs/coredump.c b/fs/coredump.c index f258c17c1841..be6403b4b14b 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -872,6 +872,9 @@ static int dump_emit_page(struct coredump_params *cprm, struct page *page) loff_t pos; ssize_t n; + if (!page) + return 0; + if (cprm->to_skip) { if (!__dump_skip(cprm, cprm->to_skip)) return 0; @@ -884,7 +887,6 @@ static int dump_emit_page(struct coredump_params *cprm, struct page *page) pos = file->f_pos; bvec_set_page(&bvec, page, PAGE_SIZE, 0); iov_iter_bvec(&iter, ITER_SOURCE, &bvec, 1, PAGE_SIZE); - iov_iter_set_copy_mc(&iter); n = __kernel_write_iter(cprm->file, &iter, &pos); if (n != PAGE_SIZE) return 0; @@ -895,10 +897,44 @@ static int dump_emit_page(struct coredump_params *cprm, struct page *page) return 1; } +/* + * If we might get machine checks from kernel accesses during the + * core dump, let's get those errors early rather than during the + * IO. This is not performance-critical enough to warrant having + * all the machine check logic in the iovec paths. + */ +#ifdef copy_mc_to_kernel + +#define dump_page_alloc() alloc_page(GFP_KERNEL) +#define dump_page_free(x) __free_page(x) +static struct page *dump_page_copy(struct page *src, struct page *dst) +{ + void *buf = kmap_local_page(src); + size_t left = copy_mc_to_kernel(page_address(dst), buf, PAGE_SIZE); + kunmap_local(buf); + return left ? NULL : dst; +} + +#else + +/* We just want to return non-NULL; it's never used. */ +#define dump_page_alloc() ERR_PTR(-EINVAL) +#define dump_page_free(x) ((void)(x)) +static inline struct page *dump_page_copy(struct page *src, struct page *dst) +{ + return src; +} +#endif + int dump_user_range(struct coredump_params *cprm, unsigned long start, unsigned long len) { unsigned long addr; + struct page *dump_page; + + dump_page = dump_page_alloc(); + if (!dump_page) + return 0; for (addr = start; addr < start + len; addr += PAGE_SIZE) { struct page *page; @@ -912,14 +948,17 @@ int dump_user_range(struct coredump_params *cprm, unsigned long start, */ page = get_dump_page(addr); if (page) { - int stop = !dump_emit_page(cprm, page); + int stop = !dump_emit_page(cprm, dump_page_copy(page, dump_page)); put_page(page); - if (stop) + if (stop) { + dump_page_free(dump_page); return 0; + } } else { dump_skip(cprm, PAGE_SIZE); } } + dump_page_free(dump_page); return 1; } #endif |