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[dfs] fixup: file_mmap and page cache 

Including cache maintenance, potential dereference of null pointer and
the use-after-free issue in page cache

Signed-off-by: shell <smokewood@qq.com>
This commit is contained in:
shell 2023-10-23 17:24:28 +08:00 committed by guo
parent 50bb71e458
commit b40d106bdc
2 changed files with 48 additions and 23 deletions
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26
components/dfs/dfs_v2/src/dfs_file_mmap.c
View File

@ -272,7 +272,7 @@ rt_err_t on_varea_shrink(struct rt_varea *varea, void *new_vaddr, rt_size_t size
rm_start = varea_start + size;
rm_end = varea_start + varea->size;
}
else if (varea_start < (char *)new_vaddr)
else
{
rm_start = varea_start;
rm_end = new_vaddr;
@ -293,6 +293,7 @@ rt_err_t on_varea_expand(struct rt_varea *varea, void *new_vaddr, rt_size_t size
rt_err_t on_varea_split(struct rt_varea *existed, void *unmap_start, rt_size_t unmap_len, struct rt_varea *subset)
{
rt_err_t rc;
struct dfs_file *file = dfs_mem_obj_get_file(existed->mem_obj);
if (file)
@ -307,12 +308,15 @@ rt_err_t on_varea_split(struct rt_varea *existed, void *unmap_start, rt_size_t u
LOG_I("file: %s%s", file->dentry->mnt->fullpath, file->dentry->pathname);
}
unmap_pages(existed, unmap_start, (char *)unmap_start + unmap_len);
rc = unmap_pages(existed, unmap_start, (char *)unmap_start + unmap_len);
if (!rc)
{
rc = unmap_pages(existed, subset->start, (char *)subset->start + subset->size);
if (!rc)
on_varea_open(subset);
}
subset->data = existed->data;
rt_atomic_add(&(file->ref_count), 1);
return RT_EOK;
return rc;
}
else
{
@ -338,8 +342,7 @@ rt_err_t on_varea_merge(struct rt_varea *merge_to, struct rt_varea *merge_from)
}
dfs_aspace_unmap(file, merge_from);
merge_from->data = RT_NULL;
rt_atomic_sub(&(file->ref_count), 1);
on_varea_close(merge_from);
return RT_EOK;
}
@ -406,7 +409,9 @@ int dfs_file_mmap(struct dfs_file *file, struct dfs_mmap2_args *mmap2)
LOG_I("mmap2 args addr: %p length: 0x%x prot: %d flags: 0x%x pgoffset: 0x%x",
mmap2->addr, mmap2->length, mmap2->prot, mmap2->flags, mmap2->pgoffset);
if (file && file->vnode && file->vnode->aspace)
if (file && file->vnode)
{
if (file->vnode->aspace)
{
/* create a va area in user space (lwp) */
rt_varea_t varea = dfs_map_user_varea_data(mmap2, file);
@ -424,10 +429,11 @@ int dfs_file_mmap(struct dfs_file *file, struct dfs_mmap2_args *mmap2)
ret = -ENOMEM;
}
}
else if (file->vnode->aspace == RT_NULL)
else
{
LOG_E("File mapping is not supported, file: %s%s", file->dentry->mnt->fullpath, file->dentry->pathname);
}
}
return ret;
}

19
components/dfs/dfs_v2/src/dfs_pcache.c
View File

@ -6,6 +6,7 @@
* Change Logs:
* Date Author Notes
* 2023-05-05 RTT Implement mnt in dfs v2.0
* 2023-10-23 Shell fix synchronization of data to icache
*/
#include "dfs_pcache.h"
@ -15,6 +16,8 @@
#include <mmu.h>
#include <tlb.h>
#include <rthw.h>
#ifdef RT_USING_PAGECACHE
#define DBG_TAG "dfs.pcache"
@ -1270,6 +1273,21 @@ void *dfs_aspace_mmap(struct dfs_file *file, struct rt_varea *varea, void *vaddr
int err = rt_varea_map_range(varea, vaddr, pg_paddr, page->size);
if (err == RT_EOK)
{
/**
* Note: While the page is mapped into user area, the data writing into the page
* is not guaranteed to be visible for machines with the *weak* memory model and
* those Harvard architecture (especially for those ARM64) cores for their
* out-of-order pipelines of data buffer. Besides if the instruction cache in the
* L1 memory system is a VIPT cache, there are chances to have the alias matching
* entry if we reuse the same page frame and map it into the same virtual address
* of the previous one.
*
* That's why we have to do synchronization and cleanup manually to ensure that
* fetching of the next instruction can see the coherent data with the data cache,
* TLB, MMU, main memory, and all the other observers in the computer system.
*/
rt_hw_cpu_icache_ops(RT_HW_CACHE_INVALIDATE, vaddr, ARCH_PAGE_SIZE);
ret = page->page;
map->varea = varea;
dfs_aspace_lock(aspace);
@ -1358,6 +1376,7 @@ int dfs_aspace_page_unmap(struct dfs_file *file, struct rt_varea *varea, void *v
{
rt_list_t *node, *tmp;
struct dfs_mmap *map;
rt_varea_unmap_page(varea, vaddr);
node = page->mmap_head.next;