565f13088f
Change the kernel to add features to vircopy and safecopies so that
transparent copy fixing won't happen to avoid deadlocks, and such copies
fail with EFAULT.
Transparently making copying work from filesystems (as normally done by
the kernel & VM when copying fails because of missing/readonly memory)
is problematic as it can happen that, for file-mapped ranges, that that
same filesystem that is blocked on the copy request is needed to satisfy
the memory range, leading to deadlock. Dito for VFS itself, if done with
a blocking call.
This change makes the copying done from a filesystem fail in such cases
with EFAULT by VFS adding the CPF_TRY flag to the grants. If a FS call
fails with EFAULT, VFS will then request the range to be made available
to VM after the FS is unblocked, allowing it to be used to satisfy the
range if need be in another VFS thread.
Similarly, for datacopies that VFS itself does, it uses the failable
vircopy variant and callers use a wrapper that talk to VM if necessary
to get the copy to work.
. kernel: add CPF_TRY flag to safecopies
. kernel: only request writable ranges to VM for the
target buffer when copying fails
. do copying in VFS TRY-first
. some fixes in VM to build SANITYCHECK mode
. add regression test for the cases where
- a FS system call needs memory mapped in a process that the
FS itself must map.
- such a range covers more than one file-mapped region.
. add 'try' mode to vircopy, physcopy
. add flags field to copy kernel call messages
. if CP_FLAG_TRY is set, do not transparently try
to fix memory ranges
. for use by VFS when accessing user buffers to avoid
deadlock
. remove some obsolete backwards compatability assignments
. VFS: let thread scheduling work for VM requests too
Allows VFS to make calls to VM while suspending and resuming
the currently running thread. Does currently not work for the
main thread.
. VM: add fix memory range call for use by VFS
Change-Id: I295794269cea51a3163519a9cfe5901301d90b32
92 lines
3.4 KiB
C
92 lines
3.4 KiB
C
/* Prototypes and definitions for VM interface. */
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#ifndef _MINIX_VM_H
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#define _MINIX_VM_H
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#include <sys/types.h>
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#include <minix/endpoint.h>
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int vm_exit(endpoint_t ep);
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int vm_fork(endpoint_t ep, int slotno, endpoint_t *child_ep);
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int vm_willexit(endpoint_t ep);
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int vm_adddma(endpoint_t proc_e, phys_bytes start, phys_bytes size);
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int vm_deldma(endpoint_t proc_e, phys_bytes start, phys_bytes size);
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int vm_getdma(endpoint_t *procp, phys_bytes *basep, phys_bytes *sizep);
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void *vm_map_phys(endpoint_t who, void *physaddr, size_t len);
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int vm_unmap_phys(endpoint_t who, void *vaddr, size_t len);
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int vm_notify_sig(endpoint_t ep, endpoint_t ipc_ep);
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int vm_set_priv(endpoint_t ep, void *buf, int sys_proc);
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int vm_update(endpoint_t src_e, endpoint_t dst_e);
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int vm_memctl(endpoint_t ep, int req);
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int vm_query_exit(endpoint_t *endpt);
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int vm_watch_exit(endpoint_t ep);
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int vm_forgetblock(u64_t id);
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void vm_forgetblocks(void);
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int minix_vfs_mmap(endpoint_t who, off_t offset, size_t len,
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dev_t dev, ino_t ino, int fd, u32_t vaddr, u16_t clearend, u16_t
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flags);
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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, off_t offset);
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int minix_vfs_mmap(endpoint_t who, off_t offset, size_t len,
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dev_t dev, ino_t ino, int fd, u32_t vaddr, u16_t clearend,
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u16_t flags);
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/* minix vfs mmap flags */
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#define MVM_WRITABLE 0x8000
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/* VM kernel request types. */
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#define VMPTYPE_NONE 0
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#define VMPTYPE_CHECK 1
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struct vm_stats_info {
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unsigned int vsi_pagesize; /* page size */
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unsigned long vsi_total; /* total number of memory pages */
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unsigned long vsi_free; /* number of free pages */
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unsigned long vsi_largest; /* largest number of consecutive free pages */
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unsigned long vsi_cached; /* number of pages cached for file systems */
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};
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struct vm_usage_info {
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vir_bytes vui_total; /* total amount of process memory */
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vir_bytes vui_common; /* part of memory mapped in more than once */
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vir_bytes vui_shared; /* shared (non-COW) part of common memory */
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};
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struct vm_region_info {
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vir_bytes vri_addr; /* base address of region */
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vir_bytes vri_length; /* length of region */
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int vri_prot; /* protection flags (PROT_) */
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int vri_flags; /* memory flags (subset of MAP_) */
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};
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#define MAX_VRI_COUNT 64 /* max. number of regions provided at once */
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int vm_info_stats(struct vm_stats_info *vfi);
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int vm_info_usage(endpoint_t who, struct vm_usage_info *vui);
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int vm_info_region(endpoint_t who, struct vm_region_info *vri, int
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count, vir_bytes *next);
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int vm_procctl_clear(endpoint_t ep);
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int vm_procctl_handlemem(endpoint_t ep, vir_bytes m1, vir_bytes m2, int wr);
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int vm_set_cacheblock(void *block, dev_t dev, off_t dev_offset,
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ino_t ino, off_t ino_offset, u32_t *flags, int blocksize);
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void *vm_map_cacheblock(dev_t dev, off_t dev_offset,
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ino_t ino, off_t ino_offset, u32_t *flags, int blocksize);
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int vm_clear_cache(dev_t dev);
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/* flags for vm cache functions */
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#define VMMC_FLAGS_LOCKED 0x01 /* someone is updating the flags; don't read/write */
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#define VMMC_DIRTY 0x02 /* dirty buffer and it may not be evicted */
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#define VMMC_EVICTED 0x04 /* VM has evicted the buffer and it's invalid */
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#define VMMC_BLOCK_LOCKED 0x08 /* client is using it and it may not be evicted */
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/* special inode number for vm cache functions */
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#define VMC_NO_INODE 0 /* to reference a disk block, no associated file */
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#endif /* _MINIX_VM_H */
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