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* Fix the mem driver to not always return invalid argument

Browse Source 
* Cleanup

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23140 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Michael Lotz 2007-12-18 18:48:50 +00:00
parent 35f6af0388
commit 9e0b9fbda5
1 changed files with 50 additions and 59 deletions
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109
src/add-ons/kernel/drivers/misc/mem.c
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@ -2,8 +2,6 @@
* Copyright 2007, Haiku, Inc. All rights reserved.
* Distributed under the terms of the MIT License.
*/
#include <Drivers.h>
#include <KernelExport.h>
#include <string.h>
@ -21,11 +19,11 @@
static status_t mem_open(const char*, uint32, void**);
static status_t mem_close(void*);
static status_t mem_free(void*);
//static status_t mem_control(void*, uint32, void*, size_t);
static status_t mem_read(void*, off_t, void*, size_t*);
static status_t mem_write(void*, off_t, const void*, size_t*);
static area_id mem_map_target(off_t position, size_t len, uint32 protection, void **va);
static area_id mem_map_target(off_t position, size_t length, uint32 protection,
void **virtualAddress);
static const char* mem_name[] = {
DEVICE_NAME,
@ -86,7 +84,6 @@ mem_open(const char* name, uint32 flags, void** cookie)
{
// not really needed.
*cookie = NULL;
return B_OK;
}
@ -104,87 +101,81 @@ mem_free(void* cookie)
return B_OK;
}
/*
status_t
mem_control(void* cookie, uint32 op, void* arg, size_t length)
{
return ENOSYS;
}
*/
status_t
mem_read(void* cookie, off_t position, void* buffer, size_t* numBytes)
{
status_t err;
void *va;
void *virtualAddress;
area_id area;
/* check perms */
err = EPERM;
if (getuid() != 0 && geteuid() != 0)
goto err1;
err = area = mem_map_target(position, *numBytes, B_READ_AREA, &va);
if (err < 0)
goto err1;
memcpy(buffer, va, *numBytes);
/* check permissions */
if (getuid() != 0 && geteuid() != 0) {
*numBytes = 0;
return EPERM;
}
area = mem_map_target(position, *numBytes, B_READ_AREA, &virtualAddress);
if (area < 0) {
*numBytes = 0;
return area;
}
memcpy(buffer, virtualAddress, *numBytes);
delete_area(area);
return B_OK;
err1:
*numBytes = 0;
return err;
}
status_t
mem_write(void* cookie, off_t position, const void* buffer, size_t* numBytes)
{
status_t err;
void *va;
void *virtualAddress;
area_id area;
/* check perms */
err = EPERM;
if (getuid() != 0 && geteuid() != 0)
goto err1;
err = area = mem_map_target(position, *numBytes, B_WRITE_AREA, &va);
if (err < 0)
goto err1;
memcpy(va, buffer, *numBytes);
/* check permissions */
if (getuid() != 0 && geteuid() != 0) {
*numBytes = 0;
return EPERM;
}
area = mem_map_target(position, *numBytes, B_WRITE_AREA, &virtualAddress);
if (area < 0) {
*numBytes = 0;
return area;
}
memcpy(virtualAddress, buffer, *numBytes);
delete_area(area);
return B_OK;
err1:
*numBytes = 0;
return err;
}
area_id
mem_map_target(off_t position, size_t len, uint32 protection, void **va)
mem_map_target(off_t position, size_t length, uint32 protection,
void **virtualAddress)
{
area_id area;
void *paddr;
void *vaddr;
int offset;
void *physicalAddress;
size_t offset;
size_t size;
/* SIZE_MAX actually but 2G should be enough anyway */
if (len > SSIZE_MAX - B_PAGE_SIZE)
if (length > SSIZE_MAX - B_PAGE_SIZE)
return EINVAL;
/* the first page address */
paddr = (void *)(addr_t)(position & ~((off_t)B_PAGE_SIZE - 1));
physicalAddress = (void *)(addr_t)(position & ~((off_t)B_PAGE_SIZE - 1));
/* offset of target into it */
offset = position - (off_t)(addr_t)paddr;
offset = position - (off_t)(addr_t)physicalAddress;
/* size of the whole mapping (page rounded) */
size = (offset + len + B_PAGE_SIZE - 1) & ~((size_t)B_PAGE_SIZE - 1);
area = map_physical_memory("mem_driver_temp",
paddr, size, B_ANY_KERNEL_ADDRESS,
protection, &vaddr);
size = (offset + length + B_PAGE_SIZE - 1) & ~((size_t)B_PAGE_SIZE - 1);
area = map_physical_memory("mem_driver_temp", physicalAddress, size,
B_ANY_KERNEL_ADDRESS, protection, virtualAddress);
if (area < 0)
return area;
*va = vaddr + offset;
return EINVAL;
*virtualAddress += offset;
return area;
}