Commit 82d6229e authored by Heiko Carstens's avatar Heiko Carstens Committed by Alexander Gordeev
Browse files

s390/uaccess: Merge cmpxchg_user_key() inline assemblies 



The inline assemblies for __cmpxchg_user_key1() and __cmpxchg_user_key2()
are identical. Get rid of the duplication and provide a common helper
function.

Suggested-by: default avatarMete Durlu <meted@linux.ibm.com>
Acked-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent d2b73ce9

arch/s390/lib/uaccess.c

+25 −55
Original line number Diff line number Diff line
@@ -150,20 +150,16 @@ EXPORT_SYMBOL(_copy_to_user_key); 


#define CMPXCHG_USER_KEY_MAX_LOOPS 128



int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval,

				  unsigned char old, unsigned char new, unsigned long key)

static nokprobe_inline int __cmpxchg_user_key_small(unsigned long address, unsigned int *uval,

						    unsigned int old, unsigned int new,

						    unsigned int mask, unsigned long key)

{

	unsigned int prev, shift, mask, _old, _new;

	unsigned long count;

	unsigned int prev;

	bool sacf_flag;

	int rc = 0;



	skey_regions_initialize();

	shift = (3 ^ (address & 3)) << 3;

	address ^= address & 3;

	_old = (unsigned int)old << shift;

	_new = (unsigned int)new << shift;

	mask = ~(0xff << shift);

	sacf_flag = enable_sacf_uaccess();

	asm_inline volatile(

		"20:	spka	0(%[key])\n"
@@ -193,8 +189,8 @@ int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval, 
		: [rc] "+&d" (rc),

		[prev] "=&d" (prev),

		[address] "+Q" (*(int *)address),

		[tmp] "+&d" (_old),

		[new] "+&d" (_new),

		[tmp] "+&d" (old),

		[new] "+&d" (new),

		[mask] "+&d" (mask),

		[count] "=a" (count)

		: [key] "%[count]" (key << 4),
@@ -202,68 +198,42 @@ int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval, 
		[max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)

		: "memory", "cc");

	disable_sacf_uaccess(sacf_flag);

	*uval = prev >> shift;

	*uval = prev;

	if (!count)

		rc = -EAGAIN;

	return rc;

}



int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval,

				  unsigned char old, unsigned char new, unsigned long key)

{

	unsigned int prev, shift, mask, _old, _new;

	int rc;



	shift = (3 ^ (address & 3)) << 3;

	address ^= address & 3;

	_old = (unsigned int)old << shift;

	_new = (unsigned int)new << shift;

	mask = ~(0xff << shift);

	rc = __cmpxchg_user_key_small(address, &prev, _old, _new, mask, key);

	*uval = prev >> shift;

	return rc;

}

EXPORT_SYMBOL(__cmpxchg_user_key1);



int __kprobes __cmpxchg_user_key2(unsigned long address, unsigned short *uval,

				  unsigned short old, unsigned short new, unsigned long key)

{

	unsigned int prev, shift, mask, _old, _new;

	unsigned long count;

	bool sacf_flag;

	int rc = 0;

	int rc;



	skey_regions_initialize();

	shift = (2 ^ (address & 2)) << 3;

	address ^= address & 2;

	_old = (unsigned int)old << shift;

	_new = (unsigned int)new << shift;

	mask = ~(0xffff << shift);

	sacf_flag = enable_sacf_uaccess();

	asm_inline volatile(

		"20:	spka	0(%[key])\n"

		"	sacf	256\n"

		"	llill	%[count],%[max_loops]\n"

		"0:	l	%[prev],%[address]\n"

		"1:	nr	%[prev],%[mask]\n"

		"	xilf	%[mask],0xffffffff\n"

		"	or	%[new],%[prev]\n"

		"	or	%[prev],%[tmp]\n"

		"2:	lr	%[tmp],%[prev]\n"

		"3:	cs	%[prev],%[new],%[address]\n"

		"4:	jnl	5f\n"

		"	xr	%[tmp],%[prev]\n"

		"	xr	%[new],%[tmp]\n"

		"	nr	%[tmp],%[mask]\n"

		"	jnz	5f\n"

		"	brct	%[count],2b\n"

		"5:	sacf	768\n"

		"	spka	%[default_key]\n"

		"21:\n"

		EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])

		EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])

		EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])

		EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])

		SKEY_REGION(20b, 21b)

		: [rc] "+&d" (rc),

		[prev] "=&d" (prev),

		[address] "+Q" (*(int *)address),

		[tmp] "+&d" (_old),

		[new] "+&d" (_new),

		[mask] "+&d" (mask),

		[count] "=a" (count)

		: [key] "%[count]" (key << 4),

		[default_key] "J" (PAGE_DEFAULT_KEY),

		[max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)

		: "memory", "cc");

	disable_sacf_uaccess(sacf_flag);

	rc = __cmpxchg_user_key_small(address, &prev, _old, _new, mask, key);

	*uval = prev >> shift;

	if (!count)

		rc = -EAGAIN;

	return rc;

}

EXPORT_SYMBOL(__cmpxchg_user_key2);