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fs/mmap: Clarify MAP_PRIVATE dependency on CONFIG_FS_RAMMAP

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This commit is contained in:
Gustavo Henrique Nihei 2021-03-15 16:35:30 -03:00 committed by Xiang Xiao
parent 4cde8dab5a
commit 00d9f81919
1 changed files with 24 additions and 7 deletions
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31
fs/mmap/fs_mmap.c
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@ -112,7 +112,7 @@ FAR void *mmap(FAR void *start, size_t length, int prot, int flags,
int fd, off_t offset) int fd, off_t offset)
{ {
FAR void *addr; FAR void *addr;
int ret = -1; int ret;
/* Since only a tiny subset of mmap() functionality, we have to verify many /* Since only a tiny subset of mmap() functionality, we have to verify many
* things. * things.
@ -132,6 +132,16 @@ FAR void *mmap(FAR void *start, size_t length, int prot, int flags,
goto errout; goto errout;
} }
#ifndef CONFIG_FS_RAMMAP
if ((flags & MAP_PRIVATE) != 0)
{
ferr("ERROR: MAP_PRIVATE is not supported without file mapping"
"emulation\n");
ret = -ENOSYS;
goto errout;
}
#endif /* CONFIG_FS_RAMMAP */
/* A length of 0 is invalid. */ /* A length of 0 is invalid. */
if (length == 0) if (length == 0)
@ -140,7 +150,7 @@ FAR void *mmap(FAR void *start, size_t length, int prot, int flags,
ret = -EINVAL; ret = -EINVAL;
goto errout; goto errout;
} }
#endif #endif /* CONFIG_DEBUG_FEATURES */
/* Check if we are just be asked to allocate memory, i.e., MAP_ANONYMOUS /* Check if we are just be asked to allocate memory, i.e., MAP_ANONYMOUS
* set meaning that the memory is not backed up from a file. The file * set meaning that the memory is not backed up from a file. The file
@ -169,17 +179,24 @@ FAR void *mmap(FAR void *start, size_t length, int prot, int flags,
return alloc; return alloc;
} }
if ((flags & MAP_PRIVATE) != 0)
{
#ifdef CONFIG_FS_RAMMAP
/* Allocate memory and copy the file into memory. We would, of course,
* do much better in the KERNEL build using the MMU.
*/
return rammap(fd, length, offset);
#endif
}
/* Perform the ioctl to get the base address of the file in 'mapped' /* Perform the ioctl to get the base address of the file in 'mapped'
* in memory. (casting to uintptr_t first eliminates complaints on some * in memory. (casting to uintptr_t first eliminates complaints on some
* architectures where the sizeof long is different from the size of * architectures where the sizeof long is different from the size of
* a pointer). * a pointer).
*/ */
if ((flags & MAP_PRIVATE) == 0) ret = nx_ioctl(fd, FIOC_MMAP, (unsigned long)((uintptr_t)&addr));
{
ret = nx_ioctl(fd, FIOC_MMAP, (unsigned long)((uintptr_t)&addr));
}
if (ret < 0) if (ret < 0)
{ {
/* Not directly mappable, probably because the underlying media does /* Not directly mappable, probably because the underlying media does