mirrors/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-12-27 11:06:41 -05:00
Code Issues Packages Projects Releases Wiki Activity

s390/uaccess: Merge cmpxchg_user_key() inline assemblies

Browse Source 
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: Mete Durlu <meted@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Heiko Carstens
2025-06-25 13:25:28 +02:00
committed by Alexander Gordeev
parent d2b73ce90a
commit 82d6229e7e
1 changed files with 25 additions and 55 deletions
Download Patch File Download Diff File Expand all files Collapse all files

80
arch/s390/lib/uaccess.c
View File

@@ -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);