657bc824c3
. libc: add vfs_mmap, a way for vfs to initiate mmap()s. This is a good special case to have as vfs is a slightly different client from regular user processes. It doesn't do it for itself, and has the dev & inode info already so the callback to VFS for the lookup isn't necessary. So it has different info to have to give to VM. . libc: also add minix_mmap64() that accepts a 64-bit offset, even though our off_t is still 32 bit now. . to support mmap, we need to create new references to FD's (such as an FD) so that the mmapped object can never be removed even if all FD's are closed. To do that we conceptually dup the filedescriptor into a new range that is only visible to the system. So there are FDS_PER_PROCESS fd's, which is more than OPEN_MAX, per process, and user processes can still use up to OPEN_MAX FD's. mmap()ped objects then get extra reference in the invisible range so user processes can't close them. The in-vfs fd_set is of size FDS_PER_PROCESS. . On exec() time, try to mmap() in the executable if available. (It is not yet available in this commit.) . To support mmap(), add do_vm_call that allows VM to lookup (to ino+dev), do i/o from and close FD's on behalf of other processes. . To make this possible, a few functions have 2 more arguments to make the target process explicit (instead of the implicit global fp) and to specify whether the request is from a user process or the system (which implies whether FD's starting at OPEN_MAX are valid). These are close_fd, common_open, actual_llseek, actual_read_write_peek, get_fd and get_filp2. Change-Id: I831551e45a6781c74313c450eb9c967a68505932
177 lines
3.2 KiB
C
177 lines
3.2 KiB
C
#define _SYSTEM 1
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#include <sys/cdefs.h>
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#include "namespace.h"
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#include <lib.h>
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#include <minix/u64.h>
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#include <minix/vm.h>
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/* INCLUDES HERE */
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#ifdef __weak_alias
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__weak_alias(vm_remap, _vm_remap)
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__weak_alias(vm_unmap, _vm_unmap)
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__weak_alias(vm_getphys, _vm_getphys)
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__weak_alias(vm_getrefcount, _vm_getrefcount)
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__weak_alias(minix_mmap, _minix_mmap)
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__weak_alias(minix_munmap, _minix_munmap)
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#endif
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#include <sys/mman.h>
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#include <stdarg.h>
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#include <string.h>
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#include <errno.h>
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void *minix_mmap_for(endpoint_t forwhom,
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void *addr, size_t len, int prot, int flags, int fd, u64_t offset)
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{
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message m;
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int r;
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m.VMM_ADDR = (vir_bytes) addr;
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m.VMM_LEN = len;
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m.VMM_PROT = prot;
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m.VMM_FLAGS = flags;
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m.VMM_FD = fd;
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m.VMM_OFFSET_LO = ex64lo(offset);
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if(forwhom != SELF) {
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m.VMM_FLAGS |= MAP_THIRDPARTY;
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m.VMM_FORWHOM = forwhom;
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} else {
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m.VMM_OFFSET_HI = ex64hi(offset);
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}
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r = _syscall(VM_PROC_NR, VM_MMAP, &m);
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if(r != OK) {
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return MAP_FAILED;
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}
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return (void *) m.VMM_RETADDR;
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}
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int minix_vfs_mmap(endpoint_t who, u32_t offset, u32_t len,
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u32_t dev, u32_t ino, u16_t fd, u32_t vaddr, u16_t clearend,
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u16_t flags)
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{
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message m;
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memset(&m, 0, sizeof(message));
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m.m_u.m_vm_vfs.who = who;
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m.m_u.m_vm_vfs.offset = offset;
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m.m_u.m_vm_vfs.dev = dev;
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m.m_u.m_vm_vfs.ino = ino;
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m.m_u.m_vm_vfs.vaddr = vaddr;
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m.m_u.m_vm_vfs.len = len;
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m.m_u.m_vm_vfs.fd = fd;
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m.m_u.m_vm_vfs.clearend_and_flags = clearend | flags;
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return _syscall(VM_PROC_NR, VM_VFS_MMAP, &m);
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}
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void *minix_mmap(void *addr, size_t len, int prot, int flags,
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int fd, off_t offset)
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{
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return minix_mmap_for(SELF, addr, len, prot, flags, fd, offset);
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}
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void *minix_mmap64(void *addr, size_t len, int prot, int flags,
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int fd, u64_t offset)
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{
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return minix_mmap_for(SELF, addr, len, prot, flags, fd, offset);
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}
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int minix_munmap(void *addr, size_t len)
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{
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message m;
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m.VMUM_ADDR = addr;
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m.VMUM_LEN = len;
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return _syscall(VM_PROC_NR, VM_MUNMAP, &m);
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}
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void *vm_remap(endpoint_t d,
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endpoint_t s,
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void *da,
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void *sa,
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size_t size)
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{
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message m;
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int r;
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m.VMRE_D = d;
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m.VMRE_S = s;
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m.VMRE_DA = (char *) da;
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m.VMRE_SA = (char *) sa;
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m.VMRE_SIZE = size;
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r = _syscall(VM_PROC_NR, VM_REMAP, &m);
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if (r != OK)
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return MAP_FAILED;
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return (void *) m.VMRE_RETA;
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}
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void *vm_remap_ro(endpoint_t d,
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endpoint_t s,
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void *da,
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void *sa,
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size_t size)
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{
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message m;
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int r;
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m.VMRE_D = d;
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m.VMRE_S = s;
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m.VMRE_DA = (char *) da;
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m.VMRE_SA = (char *) sa;
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m.VMRE_SIZE = size;
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r = _syscall(VM_PROC_NR, VM_REMAP_RO, &m);
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if (r != OK)
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return MAP_FAILED;
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return (void *) m.VMRE_RETA;
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}
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int vm_unmap(endpoint_t endpt, void *addr)
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{
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message m;
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m.VMUN_ENDPT = endpt;
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m.VMUN_ADDR = (long) addr;
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return _syscall(VM_PROC_NR, VM_SHM_UNMAP, &m);
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}
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unsigned long vm_getphys(endpoint_t endpt, void *addr)
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{
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message m;
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int r;
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m.VMPHYS_ENDPT = endpt;
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m.VMPHYS_ADDR = (long) addr;
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r = _syscall(VM_PROC_NR, VM_GETPHYS, &m);
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if (r != OK)
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return 0;
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return m.VMPHYS_RETA;
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}
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u8_t vm_getrefcount(endpoint_t endpt, void *addr)
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{
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message m;
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int r;
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m.VMREFCNT_ENDPT = endpt;
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m.VMREFCNT_ADDR = (long) addr;
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r = _syscall(VM_PROC_NR, VM_GETREF, &m);
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if (r != OK)
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return (u8_t) -1;
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return (u8_t) m.VMREFCNT_RETC;
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}
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