Commit 83ace270 authored by Michael Holzheu's avatar Michael Holzheu Committed by Martin Schwidefsky
Browse files

[S390] replace diag10() with diag10_range() function 



Currently the diag10() function can only release one page. For exploiters
that have to call diag10 on a contiguous memory region this is suboptimal.
This patch replaces the diag10() function with diag10_range() that is
able to release multiple pages. In addition to that the new function now
allows to release memory with addresses higher than 2047 MiB. This was
due to a restriction of the diagnose implementation under z/VM prior to
release 5.2.

Signed-off-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 91d37808

arch/s390/include/asm/diag.h

+15 −2
Original line number Diff line number Diff line
@@ -9,9 +9,22 @@ 
#define _ASM_S390_DIAG_H



/*

 * Diagnose 10: Release pages

 * Diagnose 10: Release page range

 */

extern void diag10(unsigned long addr);

static inline void diag10_range(unsigned long start_pfn, unsigned long num_pfn)

{

	unsigned long start_addr, end_addr;



	start_addr = start_pfn << PAGE_SHIFT;

	end_addr = (start_pfn + num_pfn - 1) << PAGE_SHIFT;



	asm volatile(

		"0:	diag	%0,%1,0x10\n"

		"1:\n"

		EX_TABLE(0b, 1b)

		EX_TABLE(1b, 1b)

		: : "a" (start_addr), "a" (end_addr));

}



/*

 * Diagnose 14: Input spool file manipulation

arch/s390/kernel/diag.c

+0 −21
Original line number Diff line number Diff line
@@ -8,27 +8,6 @@ 
#include <linux/module.h>

#include <asm/diag.h>



/*

 * Diagnose 10: Release pages

 */

void diag10(unsigned long addr)

{

	if (addr >= 0x7ff00000)

		return;

	asm volatile(

#ifdef CONFIG_64BIT

		"	sam31\n"

		"	diag	%0,%0,0x10\n"

		"0:	sam64\n"

#else

		"	diag	%0,%0,0x10\n"

		"0:\n"

#endif

		EX_TABLE(0b, 0b)

		: : "a" (addr));

}

EXPORT_SYMBOL(diag10);



/*

 * Diagnose 14: Input spool file manipulation

 */

arch/s390/mm/cmm.c

+1 −1
Original line number Diff line number Diff line
@@ -91,7 +91,7 @@ static long cmm_alloc_pages(long nr, long *counter, 
			} else

				free_page((unsigned long) npa);

		}

		diag10(addr);

		diag10_range(addr >> PAGE_SHIFT, 1);

		pa->pages[pa->index++] = addr;

		(*counter)++;

		spin_unlock(&cmm_lock);

CRA Git | Maintained and supported by SUSTech CRA and CCSE