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Commit 73d7c33e authored by KAMEZAWA Hiroyuki's avatar KAMEZAWA Hiroyuki Committed by Linus Torvalds
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kcore: /proc/kcore should use vread 



/proc/kcore has its own routine to access vmallc area.  It can be replaced
with vread().  And by this, /proc/kcore can do safe access to vmalloc
area.

Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Mike Smith <scgtrp@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d0107eb0

fs/proc/kcore.c

+2 −33
Original line number Diff line number Diff line
@@ -328,43 +328,12 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) 
				return -EFAULT;

		} else if (is_vmalloc_addr((void *)start)) {

			char * elf_buf;

			struct vm_struct *m;

			unsigned long curstart = start;

			unsigned long cursize = tsz;



			elf_buf = kzalloc(tsz, GFP_KERNEL);

			if (!elf_buf)

				return -ENOMEM;



			read_lock(&vmlist_lock);

			for (m=vmlist; m && cursize; m=m->next) {

				unsigned long vmstart;

				unsigned long vmsize;

				unsigned long msize = m->size - PAGE_SIZE;



				if (((unsigned long)m->addr + msize) < 

								curstart)

					continue;

				if ((unsigned long)m->addr > (curstart + 

								cursize))

					break;

				vmstart = (curstart < (unsigned long)m->addr ? 

					(unsigned long)m->addr : curstart);

				if (((unsigned long)m->addr + msize) > 

							(curstart + cursize))

					vmsize = curstart + cursize - vmstart;

				else

					vmsize = (unsigned long)m->addr + 

							msize - vmstart;

				curstart = vmstart + vmsize;

				cursize -= vmsize;

				/* don't dump ioremap'd stuff! (TA) */

				if (m->flags & VM_IOREMAP)

					continue;

				memcpy(elf_buf + (vmstart - start),

					(char *)vmstart, vmsize);

			}

			read_unlock(&vmlist_lock);

			vread(elf_buf, (char *)start, tsz);

			/* we have to zero-fill user buffer even if no read */

			if (copy_to_user(buffer, elf_buf, tsz)) {

				kfree(elf_buf);

				return -EFAULT;