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simplify uc_mem_protect() & uc_mem_unmap()

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This commit is contained in:
Nguyen Anh Quynh
2015-09-04 01:02:38 +08:00
parent 8a6fe6dc9d
commit 6ca85a72ed
3 changed files with 84 additions and 79 deletions
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115
uc.c
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@ -32,7 +32,7 @@
#include "qemu/include/hw/boards.h"
static uint8_t *copy_region(uch uc, MemoryRegion *mr);
static bool split_region(uch handle, MemoryRegion *mr, uint64_t address, size_t size, bool do_delete);
static bool split_region(uch handle, MemoryRegion *mr, uint64_t address, size_t size);
UNICORN_EXPORT
unsigned int uc_version(unsigned int *major, unsigned int *minor)
@ -654,8 +654,8 @@ uc_err uc_mem_map(uch handle, uint64_t address, size_t size, uint32_t perms)
return UC_ERR_OK;
}
//create a backup copy of the indicated MemoryRegion
//generally used in prepartion for splitting a MemoryRegion
// Create a backup copy of the indicated MemoryRegion.
// Generally used in prepartion for splitting a MemoryRegion.
static uint8_t *copy_region(uch handle, MemoryRegion *mr)
{
uint8_t *block = (uint8_t *)malloc(int128_get64(mr->size));
@ -666,6 +666,7 @@ static uint8_t *copy_region(uch handle, MemoryRegion *mr)
block = NULL;
}
}
return block;
}
@ -678,18 +679,18 @@ static uint8_t *copy_region(uch handle, MemoryRegion *mr)
This is a static function and callers have already done some preliminary
parameter validation.
*/
//TODO: investigate whether qemu region manipulation functions already offer this capability
static bool split_region(uch handle, MemoryRegion *mr, uint64_t address, size_t size, bool do_delete)
// TODO: investigate whether qemu region manipulation functions already offered
// this capability
static bool split_region(uch handle, MemoryRegion *mr, uint64_t address,
size_t size)
{
uint8_t *backup;
uint32_t perms;
uint64_t begin, end, chunk_end;
size_t l_size, m_size, r_size;
chunk_end = address + size;
if (address <= mr->addr && chunk_end >= mr->end) {
//trivial case, if we are deleting, just unmap
if (do_delete)
return uc_mem_unmap(handle, mr->addr, int128_get64(mr->size)) == UC_ERR_OK;
return true;
}
@ -731,17 +732,17 @@ static bool split_region(uch handle, MemoryRegion *mr, uint64_t address, size_t
r_size = (size_t)(end - chunk_end);
m_size = (size_t)(chunk_end - address);
//If there are error in any of the below operations, things are too far gone
//at that point to recover. Could try to remap orignal region, but these smaller
//allocation just failed so no guarantee that we can recover the original
//allocation at this point
// If there are error in any of the below operations, things are too far gone
// at that point to recover. Could try to remap orignal region, but these smaller
// allocation just failed so no guarantee that we can recover the original
// allocation at this point
if (l_size > 0) {
if (uc_mem_map(handle, begin, l_size, perms) != UC_ERR_OK)
goto error;
if (uc_mem_write(handle, begin, backup, l_size) != UC_ERR_OK)
goto error;
}
if (m_size > 0 && !do_delete) {
if (m_size > 0) {
if (uc_mem_map(handle, address, m_size, perms) != UC_ERR_OK)
goto error;
if (uc_mem_write(handle, address, backup + l_size, m_size) != UC_ERR_OK)
@ -764,6 +765,8 @@ uc_err uc_mem_protect(uch handle, uint64_t address, size_t size, uint32_t perms)
{
struct uc_struct* uc = (struct uc_struct *)handle;
MemoryRegion *mr;
uint64_t addr = address;
size_t count, len;
if (handle == 0)
// invalid handle
@ -789,31 +792,30 @@ uc_err uc_mem_protect(uch handle, uint64_t address, size_t size, uint32_t perms)
if (!check_mem_area(uc, address, size))
return UC_ERR_NOMEM;
//Now we know entire region is mapped, so change permissions
//If request exactly matches a region we don't need to split
mr = memory_mapping(uc, address);
if (address != mr->addr || size != int128_get64(mr->size)) {
//ouch, we are going to need to subdivide blocks
uint64_t addr = address;
size_t count = 0, len;
while(count < size) {
MemoryRegion *mr = memory_mapping(uc, addr);
len = MIN(size - count, mr->end - addr);
if (!split_region(handle, mr, addr, len, false))
return UC_ERR_NOMEM;
count += len;
addr += len;
}
//Grab a pointer to the newly split MemoryRegion
mr = memory_mapping(uc, address);
if (mr == NULL) {
//this should never happern if splitting succeeded
// Now we know entire region is mapped, so change permissions
// We may need to split regions if this area spans adjacent regions
addr = address;
count = 0;
while(count < size) {
mr = memory_mapping(uc, addr);
len = MIN(size - count, mr->end - addr);
if (!split_region(handle, mr, addr, len))
return UC_ERR_NOMEM;
}
count += len;
addr += len;
}
// Now iterate all the regions to set permission
addr = address;
count = 0;
while(count < size) {
mr = memory_mapping(uc, addr);
len = MIN(size - count, mr->end - addr);
mr->perms = perms;
uc->readonly_mem(mr, (perms & UC_PROT_WRITE) == 0);
count += len;
addr += len;
}
//regions exactly matches an existing region just change perms
mr->perms = perms;
uc->readonly_mem(mr, (perms & UC_PROT_WRITE) == 0);
return UC_ERR_OK;
}
@ -824,6 +826,8 @@ uc_err uc_mem_unmap(uch handle, uint64_t address, size_t size)
MemoryRegion *mr;
unsigned int i;
struct uc_struct* uc = (struct uc_struct *)handle;
uint64_t addr;
size_t count, len;
if (handle == 0)
// invalid handle
@ -845,12 +849,25 @@ uc_err uc_mem_unmap(uch handle, uint64_t address, size_t size)
if (!check_mem_area(uc, address, size))
return UC_ERR_NOMEM;
//Now we know entire region is mapped, so begin the delete
//check trivial case first
mr = memory_mapping(uc, address);
if (address == mr->addr && size == int128_get64(mr->size)) {
//regions exactly matches an existing region just unmap it
//this termiantes a possible recursion between this function and split_region
// Now we know entire region is mapped, so change permissions
// We may need to split regions if this area spans adjacent regions
addr = address;
count = 0;
while(count < size) {
mr = memory_mapping(uc, addr);
len = MIN(size - count, mr->end - addr);
if (!split_region(handle, mr, addr, len))
return UC_ERR_NOMEM;
count += len;
addr += len;
}
// Now iterate all the regions to set permission
addr = address;
count = 0;
while(count < size) {
mr = memory_mapping(uc, addr);
len = MIN(size - count, mr->end - addr);
uc->memory_unmap(uc, mr);
for (i = 0; i < uc->mapped_block_count; i++) {
if (uc->mapped_blocks[i] == mr) {
@ -860,18 +877,10 @@ uc_err uc_mem_unmap(uch handle, uint64_t address, size_t size)
break;
}
}
} else {
//ouch, we are going to need to subdivide blocks
size_t count = 0, len;
while(count < size) {
MemoryRegion *mr = memory_mapping(uc, address);
len = MIN(size - count, mr->end - address);
if (!split_region(handle, mr, address, len, true))
return UC_ERR_NOMEM;
count += len;
address += len;
}
count += len;
addr += len;
}
return UC_ERR_OK;
}