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IPC privileges fixes

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Kernel:
o Remove s_ipc_sendrec, instead using s_ipc_to for all send primitives
o Centralize s_ipc_to bit manipulation,
  - disallowing assignment of bits pointing to unused priv structs;
  - preventing send-to-self by not setting bit for own priv struct;
  - preserving send mask matrix symmetry in all cases
o Add IPC send mask checks to SENDA, which were missing entirely somehow
o Slightly improve IPC stats accounting for SENDA
o Remove SYSTEM from user processes' send mask
o Half-fix the dependency between boot image order and process numbers,
  - correcting the table order of the boot processes;
  - documenting the order requirement needed for proper send masks;
  - warning at boot time if the order is violated

RS:
o Add support in /etc/drivers.conf for servers that talk to user processes,
  - disallowing IPC to user processes if no "ipc" field is present
  - adding a special "USER" label to explicitly allow IPC to user processes
o Always apply IPC masks when specified; remove -i flag from service(8)
o Use kernel send mask symmetry to delay adding IPC permissions for labels
  that do not exist yet, adding them to that label's process upon creation
o Add VM to ipc permissions list for rtl8139 and fxp in drivers.conf

Left to future fixes:
o Removal of the table order vs process numbers dependency altogether,
  possibly using per-process send list structures as used for SYSTEM calls
o Proper assignment of send masks to boot processes;
  some of the assigned (~0) masks are much wider than necessary
o Proper assignment of IPC send masks for many more servers in drivers.conf
o Removal of the debugging warning about the now legitimate case where RS's
  add_forward_ipc cannot find the IPC destination's label yet
This commit is contained in:
David van Moolenbroek
2009-07-02 16:25:31 +00:00
parent aa84986819
commit b8b8f537bd
13 changed files with 297 additions and 170 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
kernel/system/do_privctl.c
View File

@@ -70,25 +70,15 @@ message *m_ptr; /* pointer to request message */
/* Now update the process' privileges as requested. */
rp->p_priv->s_trap_mask = FILLED_MASK;
for (i=0; i<BITMAP_CHUNKS(NR_SYS_PROCS); i++) {
rp->p_priv->s_ipc_to.chunk[i] = FILLED_MASK;
}
unset_sys_bit(rp->p_priv->s_ipc_to, USER_PRIV_ID);
/* All process that this process can send to must be able to reply.
* Therefore, their send masks should be updated as well.
*/
for (i=0; i<NR_SYS_PROCS; i++) {
if (get_sys_bit(rp->p_priv->s_ipc_to, i)) {
set_sys_bit(priv_addr(i)->s_ipc_to, priv_id(rp));
}
/* Set a default send mask. */
for (i=0; i < NR_SYS_PROCS; i++) {
if (i != USER_PRIV_ID)
set_sendto_bit(rp, i);
else
unset_sendto_bit(rp, i);
}
for (i=0; i<BITMAP_CHUNKS(NR_SYS_PROCS); i++) {
rp->p_priv->s_ipc_sendrec.chunk[i] = FILLED_MASK;
}
unset_sys_bit(rp->p_priv->s_ipc_sendrec, USER_PRIV_ID);
/* No I/O resources, no memory resources, no IRQs, no grant table */
priv(rp)->s_nr_io_range= 0;
priv(rp)->s_nr_mem_range= 0;
@@ -142,10 +132,14 @@ message *m_ptr; /* pointer to request message */
memcpy(priv(rp)->s_k_call_mask, priv.s_k_call_mask,
sizeof(priv(rp)->s_k_call_mask));
memcpy(&priv(rp)->s_ipc_to, &priv.s_ipc_to,
sizeof(priv(rp)->s_ipc_to));
memcpy(&priv(rp)->s_ipc_sendrec, &priv.s_ipc_sendrec,
sizeof(priv(rp)->s_ipc_sendrec));
/* Set a custom send mask. */
for (i=0; i < NR_SYS_PROCS; i++) {
if (get_sys_bit(priv.s_ipc_to, i))
set_sendto_bit(rp, i);
else
unset_sendto_bit(rp, i);
}
}
/* Done. Privileges have been set. Allow process to run again. */