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Commit 94754ecd authored by John David Anglin's avatar John David Anglin Committed by Greg Kroah-Hartman
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parisc: fix SMP races when updating PTE and TLB entries in entry.S 

commit f0a18819 upstream.

Currently, race conditions exist in the handling of TLB interruptions in
entry.S.  In particular, dirty bit updates can be lost if an accessed
interruption occurs just after the dirty bit interruption on a different
cpu.  Lost dirty bit updates result in user pages not being flushed and
general system instability.  This change adds lock and unlock macros to
synchronize all PTE and TLB updates done in entry.S.  As a result,
userspace stability is significantly improved.
Signed-off-by: default avatarJohn David Anglin  <dave.anglin@bell.net>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cdc9fd49
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Showing with 83 additions and 72 deletions
arch/parisc/kernel/entry.S
View file @ 94754ecd
...@@ -444,9 +444,41 @@ ...@@ -444,9 +444,41 @@
L2_ptep \pgd,\pte,\index,\va,\fault L2_ptep \pgd,\pte,\index,\va,\fault
.endm .endm
/* Acquire pa_dbit_lock lock. */
.macro dbit_lock spc,tmp,tmp1
#ifdef CONFIG_SMP
cmpib,COND(=),n 0,\spc,2f
load32 PA(pa_dbit_lock),\tmp
1: LDCW 0(\tmp),\tmp1
cmpib,COND(=) 0,\tmp1,1b
nop
2:
#endif
.endm
/* Release pa_dbit_lock lock without reloading lock address. */
.macro dbit_unlock0 spc,tmp
#ifdef CONFIG_SMP
or,COND(=) %r0,\spc,%r0
stw \spc,0(\tmp)
#endif
.endm
/* Release pa_dbit_lock lock. */
.macro dbit_unlock1 spc,tmp
#ifdef CONFIG_SMP
load32 PA(pa_dbit_lock),\tmp
dbit_unlock0 \spc,\tmp
#endif
.endm
/* Set the _PAGE_ACCESSED bit of the PTE. Be clever and /* Set the _PAGE_ACCESSED bit of the PTE. Be clever and
* don't needlessly dirty the cache line if it was already set */ * don't needlessly dirty the cache line if it was already set */
.macro update_ptep ptep,pte,tmp,tmp1 .macro update_ptep spc,ptep,pte,tmp,tmp1
#ifdef CONFIG_SMP
or,COND(=) %r0,\spc,%r0
LDREG 0(\ptep),\pte
#endif
ldi _PAGE_ACCESSED,\tmp1 ldi _PAGE_ACCESSED,\tmp1
or \tmp1,\pte,\tmp or \tmp1,\pte,\tmp
and,COND(<>) \tmp1,\pte,%r0 and,COND(<>) \tmp1,\pte,%r0
...@@ -455,7 +487,11 @@ ...@@ -455,7 +487,11 @@
/* Set the dirty bit (and accessed bit). No need to be /* Set the dirty bit (and accessed bit). No need to be
* clever, this is only used from the dirty fault */ * clever, this is only used from the dirty fault */
.macro update_dirty ptep,pte,tmp .macro update_dirty spc,ptep,pte,tmp
#ifdef CONFIG_SMP
or,COND(=) %r0,\spc,%r0
LDREG 0(\ptep),\pte
#endif
ldi _PAGE_ACCESSED|_PAGE_DIRTY,\tmp ldi _PAGE_ACCESSED|_PAGE_DIRTY,\tmp
or \tmp,\pte,\pte or \tmp,\pte,\pte
STREG \pte,0(\ptep) STREG \pte,0(\ptep)
...@@ -1103,11 +1139,13 @@ dtlb_miss_20w: ...@@ -1103,11 +1139,13 @@ dtlb_miss_20w:
L3_ptep ptp,pte,t0,va,dtlb_check_alias_20w L3_ptep ptp,pte,t0,va,dtlb_check_alias_20w
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
idtlbt pte,prot idtlbt pte,prot
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1127,11 +1165,13 @@ nadtlb_miss_20w: ...@@ -1127,11 +1165,13 @@ nadtlb_miss_20w:
L3_ptep ptp,pte,t0,va,nadtlb_check_alias_20w L3_ptep ptp,pte,t0,va,nadtlb_check_alias_20w
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
idtlbt pte,prot idtlbt pte,prot
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1153,7 +1193,8 @@ dtlb_miss_11: ...@@ -1153,7 +1193,8 @@ dtlb_miss_11:
L2_ptep ptp,pte,t0,va,dtlb_check_alias_11 L2_ptep ptp,pte,t0,va,dtlb_check_alias_11
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb_11 spc,pte,prot make_insert_tlb_11 spc,pte,prot
...@@ -1164,6 +1205,7 @@ dtlb_miss_11: ...@@ -1164,6 +1205,7 @@ dtlb_miss_11:
idtlbp prot,(%sr1,va) idtlbp prot,(%sr1,va)
mtsp t0, %sr1 /* Restore sr1 */ mtsp t0, %sr1 /* Restore sr1 */
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1184,7 +1226,8 @@ nadtlb_miss_11: ...@@ -1184,7 +1226,8 @@ nadtlb_miss_11:
L2_ptep ptp,pte,t0,va,nadtlb_check_alias_11 L2_ptep ptp,pte,t0,va,nadtlb_check_alias_11
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb_11 spc,pte,prot make_insert_tlb_11 spc,pte,prot
...@@ -1196,6 +1239,7 @@ nadtlb_miss_11: ...@@ -1196,6 +1239,7 @@ nadtlb_miss_11:
idtlbp prot,(%sr1,va) idtlbp prot,(%sr1,va)
mtsp t0, %sr1 /* Restore sr1 */ mtsp t0, %sr1 /* Restore sr1 */
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1216,13 +1260,15 @@ dtlb_miss_20: ...@@ -1216,13 +1260,15 @@ dtlb_miss_20:
L2_ptep ptp,pte,t0,va,dtlb_check_alias_20 L2_ptep ptp,pte,t0,va,dtlb_check_alias_20
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
f_extend pte,t0 f_extend pte,t0
idtlbt pte,prot idtlbt pte,prot
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1242,13 +1288,15 @@ nadtlb_miss_20: ...@@ -1242,13 +1288,15 @@ nadtlb_miss_20:
L2_ptep ptp,pte,t0,va,nadtlb_check_alias_20 L2_ptep ptp,pte,t0,va,nadtlb_check_alias_20
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
f_extend pte,t0 f_extend pte,t0
idtlbt pte,prot idtlbt pte,prot
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1349,11 +1397,13 @@ itlb_miss_20w: ...@@ -1349,11 +1397,13 @@ itlb_miss_20w:
L3_ptep ptp,pte,t0,va,itlb_fault L3_ptep ptp,pte,t0,va,itlb_fault
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
iitlbt pte,prot iitlbt pte,prot
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1371,11 +1421,13 @@ naitlb_miss_20w: ...@@ -1371,11 +1421,13 @@ naitlb_miss_20w:
L3_ptep ptp,pte,t0,va,naitlb_check_alias_20w L3_ptep ptp,pte,t0,va,naitlb_check_alias_20w
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
iitlbt pte,prot iitlbt pte,prot
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1397,7 +1449,8 @@ itlb_miss_11: ...@@ -1397,7 +1449,8 @@ itlb_miss_11:
L2_ptep ptp,pte,t0,va,itlb_fault L2_ptep ptp,pte,t0,va,itlb_fault
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb_11 spc,pte,prot make_insert_tlb_11 spc,pte,prot
...@@ -1408,6 +1461,7 @@ itlb_miss_11: ...@@ -1408,6 +1461,7 @@ itlb_miss_11:
iitlbp prot,(%sr1,va) iitlbp prot,(%sr1,va)
mtsp t0, %sr1 /* Restore sr1 */ mtsp t0, %sr1 /* Restore sr1 */
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1419,7 +1473,8 @@ naitlb_miss_11: ...@@ -1419,7 +1473,8 @@ naitlb_miss_11:
L2_ptep ptp,pte,t0,va,naitlb_check_alias_11 L2_ptep ptp,pte,t0,va,naitlb_check_alias_11
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb_11 spc,pte,prot make_insert_tlb_11 spc,pte,prot
...@@ -1430,6 +1485,7 @@ naitlb_miss_11: ...@@ -1430,6 +1485,7 @@ naitlb_miss_11:
iitlbp prot,(%sr1,va) iitlbp prot,(%sr1,va)
mtsp t0, %sr1 /* Restore sr1 */ mtsp t0, %sr1 /* Restore sr1 */
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1451,13 +1507,15 @@ itlb_miss_20: ...@@ -1451,13 +1507,15 @@ itlb_miss_20:
L2_ptep ptp,pte,t0,va,itlb_fault L2_ptep ptp,pte,t0,va,itlb_fault
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
f_extend pte,t0 f_extend pte,t0
iitlbt pte,prot iitlbt pte,prot
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1469,13 +1527,15 @@ naitlb_miss_20: ...@@ -1469,13 +1527,15 @@ naitlb_miss_20:
L2_ptep ptp,pte,t0,va,naitlb_check_alias_20 L2_ptep ptp,pte,t0,va,naitlb_check_alias_20
update_ptep ptp,pte,t0,t1 dbit_lock spc,t0,t1
update_ptep spc,ptp,pte,t0,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
f_extend pte,t0 f_extend pte,t0
iitlbt pte,prot iitlbt pte,prot
dbit_unlock1 spc,t0
rfir rfir
nop nop
...@@ -1499,29 +1559,13 @@ dbit_trap_20w: ...@@ -1499,29 +1559,13 @@ dbit_trap_20w:
L3_ptep ptp,pte,t0,va,dbit_fault L3_ptep ptp,pte,t0,va,dbit_fault
#ifdef CONFIG_SMP dbit_lock spc,t0,t1
cmpib,COND(=),n 0,spc,dbit_nolock_20w update_dirty spc,ptp,pte,t1
load32 PA(pa_dbit_lock),t0
dbit_spin_20w:
LDCW 0(t0),t1
cmpib,COND(=) 0,t1,dbit_spin_20w
nop
dbit_nolock_20w:
#endif
update_dirty ptp,pte,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
idtlbt pte,prot idtlbt pte,prot
#ifdef CONFIG_SMP dbit_unlock0 spc,t0
cmpib,COND(=),n 0,spc,dbit_nounlock_20w
ldi 1,t1
stw t1,0(t0)
dbit_nounlock_20w:
#endif
rfir rfir
nop nop
...@@ -1535,18 +1579,8 @@ dbit_trap_11: ...@@ -1535,18 +1579,8 @@ dbit_trap_11:
L2_ptep ptp,pte,t0,va,dbit_fault L2_ptep ptp,pte,t0,va,dbit_fault
#ifdef CONFIG_SMP dbit_lock spc,t0,t1
cmpib,COND(=),n 0,spc,dbit_nolock_11 update_dirty spc,ptp,pte,t1
load32 PA(pa_dbit_lock),t0
dbit_spin_11:
LDCW 0(t0),t1
cmpib,= 0,t1,dbit_spin_11
nop
dbit_nolock_11:
#endif
update_dirty ptp,pte,t1
make_insert_tlb_11 spc,pte,prot make_insert_tlb_11 spc,pte,prot
...@@ -1557,13 +1591,7 @@ dbit_nolock_11: ...@@ -1557,13 +1591,7 @@ dbit_nolock_11:
idtlbp prot,(%sr1,va) idtlbp prot,(%sr1,va)
mtsp t1, %sr1 /* Restore sr1 */ mtsp t1, %sr1 /* Restore sr1 */
#ifdef CONFIG_SMP dbit_unlock0 spc,t0
cmpib,COND(=),n 0,spc,dbit_nounlock_11
ldi 1,t1
stw t1,0(t0)
dbit_nounlock_11:
#endif
rfir rfir
nop nop
...@@ -1575,32 +1603,15 @@ dbit_trap_20: ...@@ -1575,32 +1603,15 @@ dbit_trap_20:
L2_ptep ptp,pte,t0,va,dbit_fault L2_ptep ptp,pte,t0,va,dbit_fault
#ifdef CONFIG_SMP dbit_lock spc,t0,t1
cmpib,COND(=),n 0,spc,dbit_nolock_20 update_dirty spc,ptp,pte,t1
load32 PA(pa_dbit_lock),t0
dbit_spin_20:
LDCW 0(t0),t1
cmpib,= 0,t1,dbit_spin_20
nop
dbit_nolock_20:
#endif
update_dirty ptp,pte,t1
make_insert_tlb spc,pte,prot make_insert_tlb spc,pte,prot
f_extend pte,t1 f_extend pte,t1
idtlbt pte,prot idtlbt pte,prot
dbit_unlock0 spc,t0
#ifdef CONFIG_SMP
cmpib,COND(=),n 0,spc,dbit_nounlock_20
ldi 1,t1
stw t1,0(t0)
dbit_nounlock_20:
#endif
rfir rfir
nop nop
......
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