cca24d06d8
kernel (sys task). The main reason is that these would have to become cpu local variables on SMP. Once the system task is not a task but a genuine part of the kernel there is even less reason to have these extra variables as proc_ptr will already contain all neccessary information. In addition converting who_e to the process pointer and back again all the time will be avoided. Although proc_ptr will contain all important information, accessing it as a cpu local variable will be fairly expensive, hence the value would be assigned to some on stack local variable. Therefore it is better to add the 'caller' argument to the syscall handlers to pass the value on stack anyway. It also clearly denotes on who's behalf is the syscall being executed. This patch also ANSIfies the syscall function headers. Last but not least, it also fixes a potential bug in virtual_copy_f() in case the check is disabled. So far the function in case of a failure could possible reuse an old who_p in case this function had not been called from the system task. virtual_copy_f() takes the caller as a parameter too. In case the checking is disabled, the caller must be NULL and non NULL if it is enabled as we must be able to suspend the caller.
118 lines
3.5 KiB
C
118 lines
3.5 KiB
C
/* The kernel call implemented in this file:
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* m_type: SYS_UMAP
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*
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* The parameters for this kernel call are:
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* m5_i1: CP_SRC_PROC_NR (process number)
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* m5_s1: CP_SRC_SPACE (segment where address is: T, D, or S)
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* m5_l1: CP_SRC_ADDR (virtual address)
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* m5_l2: CP_DST_ADDR (returns physical address)
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* m5_l3: CP_NR_BYTES (size of datastructure)
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*/
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#include "../system.h"
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#include <minix/endpoint.h>
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#if USE_UMAP
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/*==========================================================================*
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* do_umap *
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*==========================================================================*/
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PUBLIC int do_umap(struct proc * caller, message * m_ptr)
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{
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/* Map virtual address to physical, for non-kernel processes. */
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int seg_type = m_ptr->CP_SRC_SPACE & SEGMENT_TYPE;
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int seg_index = m_ptr->CP_SRC_SPACE & SEGMENT_INDEX;
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vir_bytes offset = m_ptr->CP_SRC_ADDR;
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int count = m_ptr->CP_NR_BYTES;
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int endpt = (int) m_ptr->CP_SRC_ENDPT;
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int proc_nr, r;
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int naughty = 0;
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phys_bytes phys_addr = 0, lin_addr = 0;
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struct proc *targetpr;
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/* Verify process number. */
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if (endpt == SELF)
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proc_nr = _ENDPOINT_P(caller->p_endpoint);
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else
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if (! isokendpt(endpt, &proc_nr))
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return(EINVAL);
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targetpr = proc_addr(proc_nr);
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/* See which mapping should be made. */
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switch(seg_type) {
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case LOCAL_SEG:
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phys_addr = lin_addr = umap_local(targetpr, seg_index, offset, count);
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if(!lin_addr) return EFAULT;
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naughty = 1;
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break;
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case REMOTE_SEG:
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phys_addr = lin_addr = umap_remote(targetpr, seg_index, offset, count);
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if(!lin_addr) return EFAULT;
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naughty = 1;
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break;
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case LOCAL_VM_SEG:
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if(seg_index == MEM_GRANT) {
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vir_bytes newoffset;
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endpoint_t newep;
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int new_proc_nr;
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if(verify_grant(targetpr->p_endpoint, ANY, offset, count, 0, 0,
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&newoffset, &newep) != OK) {
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kprintf("SYSTEM: do_umap: verify_grant in %s, grant %d, bytes 0x%lx, failed, caller %s\n", targetpr->p_name, offset, count, caller->p_name);
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proc_stacktrace(caller);
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return EFAULT;
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}
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if(!isokendpt(newep, &new_proc_nr)) {
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kprintf("SYSTEM: do_umap: isokendpt failed\n");
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return EFAULT;
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}
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/* New lookup. */
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offset = newoffset;
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targetpr = proc_addr(new_proc_nr);
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seg_index = D;
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}
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if(seg_index == T || seg_index == D || seg_index == S) {
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phys_addr = lin_addr = umap_local(targetpr, seg_index, offset, count);
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} else {
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kprintf("SYSTEM: bogus seg type 0x%lx\n", seg_index);
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return EFAULT;
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}
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if(!lin_addr) {
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kprintf("SYSTEM:do_umap: umap_local failed\n");
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return EFAULT;
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}
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if(vm_lookup(targetpr, lin_addr, &phys_addr, NULL) != OK) {
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kprintf("SYSTEM:do_umap: vm_lookup failed\n");
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return EFAULT;
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}
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if(phys_addr == 0)
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minix_panic("vm_lookup returned zero physical address", NO_NUM);
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break;
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default:
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if((r=arch_umap(targetpr, offset, count, seg_type, &lin_addr))
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!= OK)
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return r;
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phys_addr = lin_addr;
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}
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if(vm_running && !vm_contiguous(targetpr, lin_addr, count)) {
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kprintf("SYSTEM:do_umap: not contiguous\n");
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return EFAULT;
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}
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m_ptr->CP_DST_ADDR = phys_addr;
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if(naughty || phys_addr == 0) {
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kprintf("kernel: umap 0x%x done by %d / %s, pc 0x%lx, 0x%lx -> 0x%lx\n",
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seg_type, caller->p_endpoint, caller->p_name,
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caller->p_reg.pc, offset, phys_addr);
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kprintf("caller stack: ");
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proc_stacktrace(caller);
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}
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return (phys_addr == 0) ? EFAULT: OK;
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}
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#endif /* USE_UMAP */
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