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Commit 4d3b0664 authored by Michael Holzheu's avatar Michael Holzheu Committed by Martin Schwidefsky
Browse files

s390: Allow vmalloc target buffers for copy_from_oldmem() 



Currently copy_from_oldmem() is not able to copy to virtual memory.
When using kexec pre-allocated ELF header, copy_from_oldmem()
is used to copy the ELF notes information to vmalloc buffers.

So fix this and use the new function copy_from_realmem() that allows
copying also to vmalloc memory.

Signed-off-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 22bfda66

arch/s390/kernel/crash_dump.c

+20 −22
Original line number Diff line number Diff line
@@ -40,28 +40,26 @@ static inline void *load_real_addr(void *addr) 
}



/*

 * Copy up to one page to vmalloc or real memory

 * Copy real to virtual or real memory

 */

static ssize_t copy_page_real(void *buf, void *src, size_t csize)

static int copy_from_realmem(void *dest, void *src, size_t count)

{

	size_t size;

	unsigned long size;

	int rc;



	if (is_vmalloc_addr(buf)) {

		BUG_ON(csize >= PAGE_SIZE);

		/* If buf is not page aligned, copy first part */

		size = min(roundup(__pa(buf), PAGE_SIZE) - __pa(buf), csize);

		if (size) {

			if (memcpy_real(load_real_addr(buf), src, size))

	if (!count)

		return 0;

	if (!is_vmalloc_or_module_addr(dest))

		return memcpy_real(dest, src, count);

	do {

		size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK));

		if (memcpy_real(load_real_addr(dest), src, size))

			return -EFAULT;

			buf += size;

		count -= size;

		dest += size;

		src += size;

		}

		/* Copy second part */

		size = csize - size;

		return (size) ? memcpy_real(load_real_addr(buf), src, size) : 0;

	} else {

		return memcpy_real(buf, src, csize);

	}

	} while (count);

	return 0;

}



/*
@@ -114,7 +112,7 @@ static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize, 
		rc = copy_to_user_real((void __force __user *) buf,

				       (void *) src, csize);

	else

		rc = copy_page_real(buf, (void *) src, csize);

		rc = copy_from_realmem(buf, (void *) src, csize);

	return (rc == 0) ? rc : csize;

}
@@ -210,7 +208,7 @@ int copy_from_oldmem(void *dest, void *src, size_t count) 
	if (OLDMEM_BASE) {

		if ((unsigned long) src < OLDMEM_SIZE) {

			copied = min(count, OLDMEM_SIZE - (unsigned long) src);

			rc = memcpy_real(dest, src + OLDMEM_BASE, copied);

			rc = copy_from_realmem(dest, src + OLDMEM_BASE, copied);

			if (rc)

				return rc;

		}
@@ -223,7 +221,7 @@ int copy_from_oldmem(void *dest, void *src, size_t count) 
				return rc;

		}

	}

	return memcpy_real(dest + copied, src + copied, count - copied);

	return copy_from_realmem(dest + copied, src + copied, count - copied);

}



/*