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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 | #ifndef _LINUX_POLL_H #define _LINUX_POLL_H #include <asm/poll.h> #ifdef __KERNEL__ #include <linux/wait.h> #include <linux/string.h> #include <asm/uaccess.h> struct poll_table_entry { struct file * filp; struct wait_queue wait; struct wait_queue ** wait_address; }; typedef struct poll_table_struct { unsigned int nr; struct poll_table_entry * entry; } poll_table; #define __MAX_POLL_TABLE_ENTRIES (PAGE_SIZE / sizeof (struct poll_table_entry)) extern inline void poll_wait(struct file * filp, struct wait_queue ** wait_address, poll_table *p) { struct poll_table_entry * entry; if (!p || !wait_address) return; if (p->nr >= __MAX_POLL_TABLE_ENTRIES) return; entry = p->entry + p->nr; entry->filp = filp; filp->f_count++; entry->wait_address = wait_address; entry->wait.task = current; entry->wait.next = NULL; add_wait_queue(wait_address,&entry->wait); p->nr++; } /* * For the kernel fd_set we use a fixed set-size for allocation purposes. * This set-size doesn't necessarily bear any relation to the size the user * uses, but should preferably obviously be larger than any possible user * size (NR_OPEN bits). * * We need 6 bitmaps (in/out/ex for both incoming and outgoing), and we * allocate one page for all the bitmaps. Thus we have 8*PAGE_SIZE bits, * to be divided by 6. And we'd better make sure we round to a full * long-word (in fact, we'll round to 64 bytes). */ #define KFDS_64BLOCK ((PAGE_SIZE/(6*64))*64) #define KFDS_NR (KFDS_64BLOCK*8 > NR_OPEN ? NR_OPEN : KFDS_64BLOCK*8) typedef unsigned long kernel_fd_set[KFDS_NR/__NFDBITS]; typedef struct { kernel_fd_set in, out, ex; kernel_fd_set res_in, res_out, res_ex; } fd_set_buffer; /* * We do a VERIFY_WRITE here even though we are only reading this time: * we'll write to it eventually.. * * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned. */ static inline int get_fd_set(unsigned long nr, void *ufdset, unsigned long *fdset) { /* round up nr to nearest "unsigned long" */ nr = (nr + 8*sizeof(long) - 1) / (8*sizeof(long)) * sizeof(long); if (ufdset) { int error; error = verify_area(VERIFY_WRITE, ufdset, nr); if (!error) error = __copy_from_user(fdset, ufdset, nr); return error; } memset(fdset, 0, nr); return 0; } static inline void set_fd_set(unsigned long nr, void *ufdset, unsigned long *fdset) { if (ufdset) { nr = (nr + 8*sizeof(long) - 1) / (8*sizeof(long))*sizeof(long); __copy_to_user(ufdset, fdset, nr); } } static inline void zero_fd_set(unsigned long nr, unsigned long *fdset) { nr = (nr + 8*sizeof(long) - 1) / (8*sizeof(long)) * sizeof(long); memset(fdset, 0, nr); } extern int do_select(int n, fd_set_buffer *fds, unsigned long timeout); #endif /* KERNEL */ #endif /* _LINUX_POLL_H */ |