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Søren Sandmann Pedersen
2004-11-04 15:25:39 +00:00
parent e16af9c730
commit 1fa465fb26
4 changed files with 101 additions and 24 deletions
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80
sysprof-module.c
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@ -7,14 +7,13 @@
#include <asm/atomic.h>
#include <linux/kernel.h> /* Needed for KERN_ALERT */
#include <linux/module.h> /* Needed by all modules */
#ifdef KERNEL24
# include <linux/tqueue.h>
#endif
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <asm/uaccess.h>
#include <linux/poll.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include "sysprof-module.h"
@ -79,13 +78,76 @@ init_userspace_reader (userspace_reader *reader,
reader->page = NULL;
}
/* Access another process' address space.
* Source/target buffer must be kernel space,
* Do not walk the page table directly, use get_user_pages
*/
static int x_access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write)
{
struct mm_struct *mm;
struct vm_area_struct *vma;
struct page *page;
void *old_buf = buf;
mm = tsk->mm;
if (!mm)
return 0;
down_read(&mm->mmap_sem);
/* ignore errors, just check how much was sucessfully transfered */
while (len) {
int bytes, ret, offset;
void *maddr;
ret = get_user_pages(tsk, mm, addr, 1,
write, 1, &page, &vma);
if (ret <= 0)
break;
bytes = len;
offset = addr & (PAGE_SIZE-1);
if (bytes > PAGE_SIZE-offset)
bytes = PAGE_SIZE-offset;
flush_cache_page(vma, addr);
maddr = kmap(page);
if (write) {
copy_to_user_page(vma, page, addr,
maddr + offset, buf, bytes);
set_page_dirty_lock(page);
} else {
copy_from_user_page(vma, page, addr,
buf, maddr + offset, bytes);
}
kunmap(page);
page_cache_release(page);
len -= bytes;
buf += bytes;
addr += bytes;
}
up_read(&mm->mmap_sem);
return buf - old_buf;
}
static int
read_user_space (userspace_reader *reader,
unsigned long address,
unsigned long *result)
{
#if 0
unsigned long user_page = (address & PAGE_MASK);
int res;
#endif
return x_access_process_vm(reader->task, address, result, 4, 0);
}
#if 0
struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
if (user_page == 0)
return 0;
@ -93,19 +155,24 @@ read_user_space (userspace_reader *reader,
if (!reader->user_page || user_page != reader->user_page) {
int found;
struct page *page;
pte_t pte;
found = get_user_pages (reader->task, reader->task->mm, user_page,
1, 0, 0, &page, NULL);
found = get_user_pages (reader->task, reader->task->mm,
user_page, 1, 0, 0, &page, NULL);
if (!found)
return 0;
if (!pte_present (page))
return 0;
if (reader->user_page)
kunmap (reader->page);
reader->user_page = user_page;
reader->kernel_page = (unsigned long)kmap (page);
reader->user_page = user_page;
reader->page = page;
}
if (get_user (res, (int *)(reader->kernel_page + (address - user_page))) != 0)
@ -115,6 +182,7 @@ read_user_space (userspace_reader *reader,
return 1;
}
#endif
static void
done_userspace_reader (userspace_reader *reader)