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Commit 191a2fa0 authored by Michael Holzheu's avatar Michael Holzheu Committed by Martin Schwidefsky
Browse files

s390/kdump: Allow copy_oldmem_page() copy to virtual memory 



The kdump mmap patch series (git commit 83086978) changed the
requirements for copy_oldmem_page(). Now this function is used for copying
to virtual memory.

So implement vmalloc support for the s390 version of copy_oldmem_page().

Signed-off-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 5a74953f

arch/s390/kernel/crash_dump.c

+47 −4
Original line number Diff line number Diff line
@@ -21,6 +21,48 @@ 
#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))

#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))





/*

 * Return physical address for virtual address

 */

static inline void *load_real_addr(void *addr)

{

	unsigned long real_addr;



	asm volatile(

		   "	lra     %0,0(%1)\n"

		   "	jz	0f\n"

		   "	la	%0,0\n"

		   "0:"

		   : "=a" (real_addr) : "a" (addr) : "cc");

	return (void *)real_addr;

}



/*

 * Copy up to one page to vmalloc or real memory

 */

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

{

	size_t size;



	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))

				return -EFAULT;

			buf += 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);

	}

}



/*

 * Copy one page from "oldmem"

 *
@@ -32,6 +74,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, 
			 size_t csize, unsigned long offset, int userbuf)

{

	unsigned long src;

	int rc;



	if (!csize)

		return 0;
@@ -43,11 +86,11 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, 
		 src < OLDMEM_BASE + OLDMEM_SIZE)

		src -= OLDMEM_BASE;

	if (userbuf)

		copy_to_user_real((void __force __user *) buf, (void *) src,

				  csize);

		rc = copy_to_user_real((void __force __user *) buf,

				       (void *) src, csize);

	else

		memcpy_real(buf, (void *) src, csize);

	return csize;

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

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

}



/*