From: Ben Gras Date: Thu, 29 Jun 2006 14:24:07 +0000 (+0000) Subject: 3rd fix for improper behaviour on crashing driver with safe_io_conversion X-Git-Tag: v3.1.3~273 X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/examples/outline.c?a=commitdiff_plain;h=0323892f7125a24ed997040838f44764d965f5cd;p=minix.git 3rd fix for improper behaviour on crashing driver with safe_io_conversion --- diff --git a/servers/fs/device.c b/servers/fs/device.c index 914fd233b..3426cbc49 100644 --- a/servers/fs/device.c +++ b/servers/fs/device.c @@ -32,10 +32,11 @@ #define ELEMENTS(a) (sizeof(a)/sizeof((a)[0])) -FORWARD _PROTOTYPE( int safe_io_conversion, (endpoint_t, int, +FORWARD _PROTOTYPE( int safe_io_conversion, (endpoint_t, cp_grant_id_t *, int *, cp_grant_id_t *, int, endpoint_t *, - void *, int *, vir_bytes, off_t *)); -FORWARD _PROTOTYPE( void safe_io_cleanup, (cp_grant_id_t, cp_grant_id_t *, int)); + void **, int *, vir_bytes, off_t *)); +FORWARD _PROTOTYPE( void safe_io_cleanup, (cp_grant_id_t, cp_grant_id_t *, + int)); extern int dmap_size; PRIVATE int dummyproc; @@ -143,10 +144,12 @@ PUBLIC void dev_status(message *m) revive(endpt, st.REP_STATUS); break; case DEV_IO_READY: - select_notified(d, st.DEV_MINOR, st.DEV_SEL_OPS); + select_notified(d, st.DEV_MINOR, + st.DEV_SEL_OPS); break; default: - printf("FS: unrecognized reply %d to DEV_STATUS\n", st.m_type); + printf("FS: unrecognized reply %d to " + "DEV_STATUS\n", st.m_type); /* Fall through. */ case DEV_NO_STATUS: get_more = 0; @@ -160,16 +163,15 @@ PUBLIC void dev_status(message *m) /*===========================================================================* * safe_io_conversion * *===========================================================================*/ -PRIVATE int safe_io_conversion(driver, dev, gid, op, gids, gids_size, +PRIVATE int safe_io_conversion(driver, gid, op, gids, gids_size, io_ept, buf, vec_grants, bytes, pos) endpoint_t driver; -int dev; cp_grant_id_t *gid; int *op; cp_grant_id_t *gids; int gids_size; endpoint_t *io_ept; -void *buf; +void **buf; int *vec_grants; vir_bytes bytes; off_t *pos; @@ -177,7 +179,7 @@ off_t *pos; int access = 0, size; int j; iovec_t *v; - static iovec_t new_iovec[NR_IOREQS]; + static iovec_t new_iovec[NR_IOREQS]; /* Number of grants allocated in vector I/O. */ *vec_grants = 0; @@ -193,7 +195,7 @@ off_t *pos; *op = *op == DEV_READ ? DEV_READ_S : DEV_WRITE_S; if((*gid=cpf_grant_magic(driver, *io_ept, - (vir_bytes) buf, bytes, + (vir_bytes) *buf, bytes, *op == DEV_READ_S ? CPF_WRITE : CPF_READ)) < 0) { panic(__FILE__, "cpf_grant_magic of buffer failed\n", NO_NUM); @@ -206,15 +208,17 @@ off_t *pos; *op = *op == DEV_GATHER ? DEV_GATHER_S : DEV_SCATTER_S; /* Grant access to my new i/o vector. */ - if((*gid = cpf_grant_direct(driver, (vir_bytes) - new_iovec, bytes * sizeof(iovec_t), + if((*gid = cpf_grant_direct(driver, + (vir_bytes) new_iovec, bytes * sizeof(iovec_t), CPF_READ | CPF_WRITE)) < 0) { panic(__FILE__, "cpf_grant_direct of vector failed", NO_NUM); } - v = (iovec_t *) buf; + v = (iovec_t *) *buf; /* Grant access to i/o buffers. */ for(j = 0; j < bytes; j++) { + if(j >= NR_IOREQS) + panic(__FILE__, "vec too big", bytes); new_iovec[j].iov_addr = gids[j] = cpf_grant_direct(driver, (vir_bytes) v[j].iov_addr, v[j].iov_size, @@ -226,6 +230,9 @@ off_t *pos; new_iovec[j].iov_size = v[j].iov_size; (*vec_grants)++; } + + /* Set user's vector to the new one. */ + *buf = new_iovec; break; case DEV_IOCTL: *pos = *io_ept; /* Old endpoint in POSITION field. */ @@ -238,7 +245,7 @@ off_t *pos; * order to disambiguate requests with DEV_IOCTL_S. */ if((*gid=cpf_grant_magic(driver, *io_ept, - (vir_bytes) buf, size, access)) < 0) { + (vir_bytes) *buf, size, access)) < 0) { panic(__FILE__, "cpf_grant_magic failed (ioctl)\n", NO_NUM); @@ -293,13 +300,21 @@ int bytes; /* how many bytes to transfer */ struct dmap *dp; int r, safe; message m; + iovec_t *v; + cp_grant_id_t gid = GRANT_INVALID; + int vec_grants; /* Determine task dmap. */ dp = &dmap[(dev >> MAJOR) & BYTE]; + /* The io vector copying relies on this I/O being for FS itself. */ + if(proc_e != FS_PROC_NR) + panic(__FILE__, "doing dev_bio for non-self", proc_e); + for (;;) { int op_used; + void *buf_used; static cp_grant_id_t gids[NR_IOREQS]; cp_grant_id_t gid = GRANT_INVALID; int vec_grants; @@ -311,17 +326,19 @@ int bytes; /* how many bytes to transfer */ } /* By default, these are right. */ - m.IO_ENDPT = proc_e; - m.ADDRESS = buf; + m.IO_ENDPT = proc_e; + m.ADDRESS = buf; + buf_used = buf; /* Convert parameters to 'safe mode'. */ op_used = op; - safe = safe_io_conversion(dp->dmap_driver, dev, &gid, - &op_used, gids, NR_IOREQS, &m.IO_ENDPT, buf, + safe = safe_io_conversion(dp->dmap_driver, &gid, + &op_used, gids, NR_IOREQS, &m.IO_ENDPT, &buf_used, &vec_grants, bytes, &pos); /* Set up rest of the message. */ if(safe) m.IO_GRANT = (char *) gid; + m.m_type = op_used; m.DEVICE = (dev >> MINOR) & BYTE; m.POSITION = pos; @@ -377,6 +394,11 @@ int bytes; /* how many bytes to transfer */ if (m.REP_STATUS == SUSPEND) { panic(__FILE__, "dev_bio: driver returned SUSPEND", NO_NUM); } + + if(buf != buf_used) { + memcpy(buf, buf_used, bytes * sizeof(iovec_t)); + } + return(m.REP_STATUS); } } @@ -399,6 +421,7 @@ int flags; /* special flags, like O_NONBLOCK */ cp_grant_id_t gid = GRANT_INVALID; static cp_grant_id_t gids[NR_IOREQS]; int vec_grants = 0, orig_op, safe; + void *buf_used; /* Determine task dmap. */ dp = &dmap[(dev >> MAJOR) & BYTE]; @@ -421,8 +444,13 @@ int flags; /* special flags, like O_NONBLOCK */ dev_mess.ADDRESS = buf; /* Convert DEV_* to DEV_*_S variants. */ - safe = safe_io_conversion(dp->dmap_driver, dev, &gid, - &op, gids, NR_IOREQS, &dev_mess.IO_ENDPT, buf, &vec_grants, bytes, &pos); + buf_used = buf; + safe = safe_io_conversion(dp->dmap_driver, &gid, + &op, gids, NR_IOREQS, &dev_mess.IO_ENDPT, &buf_used, + &vec_grants, bytes, &pos); + + if(buf != buf_used) + panic(__FILE__,"dev_io: safe_io_conversion changed buffer", NO_NUM); /* If the safe conversion was done, set the ADDRESS to * the grant id.