| 1 | /* The kernel call implemented in this file:
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| 2 | * m_type: SYS_VIRCOPY, SYS_PHYSCOPY
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| 3 | *
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| 4 | * The parameters for this kernel call are:
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| 5 | * m5_c1: CP_SRC_SPACE source virtual segment
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| 6 | * m5_l1: CP_SRC_ADDR source offset within segment
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| 7 | * m5_i1: CP_SRC_PROC_NR source process number
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| 8 | * m5_c2: CP_DST_SPACE destination virtual segment
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| 9 | * m5_l2: CP_DST_ADDR destination offset within segment
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| 10 | * m5_i2: CP_DST_PROC_NR destination process number
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| 11 | * m5_l3: CP_NR_BYTES number of bytes to copy
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| 12 | */
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| 13 |
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| 14 | #include "../system.h"
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| 15 | #include <minix/type.h>
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| 16 |
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| 17 | #if (USE_VIRCOPY || USE_PHYSCOPY)
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| 18 |
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| 19 | /*===========================================================================*
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| 20 | * do_copy *
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| 21 | *===========================================================================*/
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| 22 | PUBLIC int do_copy(m_ptr)
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| 23 | register message *m_ptr; /* pointer to request message */
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| 24 | {
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| 25 | /* Handle sys_vircopy() and sys_physcopy(). Copy data using virtual or
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| 26 | * physical addressing. Although a single handler function is used, there
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| 27 | * are two different kernel calls so that permissions can be checked.
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| 28 | */
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| 29 | struct vir_addr vir_addr[2]; /* virtual source and destination address */
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| 30 | phys_bytes bytes; /* number of bytes to copy */
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| 31 | int i;
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| 32 |
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| 33 | /* Dismember the command message. */
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| 34 | vir_addr[_SRC_].proc_nr = m_ptr->CP_SRC_PROC_NR;
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| 35 | vir_addr[_SRC_].segment = m_ptr->CP_SRC_SPACE;
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| 36 | vir_addr[_SRC_].offset = (vir_bytes) m_ptr->CP_SRC_ADDR;
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| 37 | vir_addr[_DST_].proc_nr = m_ptr->CP_DST_PROC_NR;
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| 38 | vir_addr[_DST_].segment = m_ptr->CP_DST_SPACE;
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| 39 | vir_addr[_DST_].offset = (vir_bytes) m_ptr->CP_DST_ADDR;
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| 40 | bytes = (phys_bytes) m_ptr->CP_NR_BYTES;
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| 41 |
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| 42 | /* Now do some checks for both the source and destination virtual address.
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| 43 | * This is done once for _SRC_, then once for _DST_.
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| 44 | */
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| 45 | for (i=_SRC_; i<=_DST_; i++) {
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| 46 |
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| 47 | /* Check if process number was given implictly with SELF and is valid. */
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| 48 | if (vir_addr[i].proc_nr == SELF) vir_addr[i].proc_nr = m_ptr->m_source;
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| 49 | if (! isokprocn(vir_addr[i].proc_nr) && vir_addr[i].segment != PHYS_SEG)
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| 50 | return(EINVAL);
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| 51 |
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| 52 | /* Check if physical addressing is used without SYS_PHYSCOPY. */
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| 53 | if ((vir_addr[i].segment & PHYS_SEG) &&
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| 54 | m_ptr->m_type != SYS_PHYSCOPY) return(EPERM);
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| 55 | }
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| 56 |
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| 57 | /* Check for overflow. This would happen for 64K segments and 16-bit
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| 58 | * vir_bytes. Especially copying by the PM on do_fork() is affected.
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| 59 | */
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| 60 | if (bytes != (vir_bytes) bytes) return(E2BIG);
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| 61 |
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| 62 | /* Now try to make the actual virtual copy. */
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| 63 | return( virtual_copy(&vir_addr[_SRC_], &vir_addr[_DST_], bytes) );
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| 64 | }
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| 65 | #endif /* (USE_VIRCOPY || USE_PHYSCOPY) */
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| 66 |
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