Commit 34525e1f authored by Martin Schwidefsky's avatar Martin Schwidefsky

s390: store breaking event address only for program checks

The principles of operations specifies that the breaking event address
is stored to the address 0x110 in the prefix page only for program checks.
The last branch in user space is lost as soon as a branch in kernel space
is executed after e.g. an svc. This makes it impossible to accurately
maintain the breaking event address for a user space process.

Simplify the code, just copy the current breaking event address from
0x110 to the task structure for program checks from user space.
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 3b1bea01
......@@ -103,8 +103,7 @@ _PIF_WORK = (_PIF_PER_TRAP)
CHECK_STACK 1<<STACK_SHIFT,\savearea
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j 3f
1: LAST_BREAK %r14
UPDATE_VTIME %r14,%r15,\timer
1: UPDATE_VTIME %r14,%r15,\timer
2: lg %r15,__LC_ASYNC_STACK # load async stack
3: la %r11,STACK_FRAME_OVERHEAD(%r15)
.endm
......@@ -121,18 +120,6 @@ _PIF_WORK = (_PIF_PER_TRAP)
mvc __LC_LAST_UPDATE_TIMER(8),\enter_timer
.endm
.macro LAST_BREAK scratch
srag \scratch,%r10,23
#ifdef CONFIG_HAVE_MARCH_Z990_FEATURES
jz .+10
stg %r10,__TASK_thread+__THREAD_last_break(%r12)
#else
jz .+14
lghi \scratch,__TASK_thread
stg %r10,__THREAD_last_break(\scratch,%r12)
#endif
.endm
.macro REENABLE_IRQS
stg %r8,__LC_RETURN_PSW
ni __LC_RETURN_PSW,0xbf
......@@ -278,15 +265,14 @@ ENTRY(system_call)
stpt __LC_SYNC_ENTER_TIMER
.Lsysc_stmg:
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_CURRENT
lghi %r13,__TASK_thread
lghi %r14,_PIF_SYSCALL
.Lsysc_per:
lg %r15,__LC_KERNEL_STACK
la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
LAST_BREAK %r13
.Lsysc_vtime:
UPDATE_VTIME %r10,%r13,__LC_SYNC_ENTER_TIMER
UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW
......@@ -294,12 +280,7 @@ ENTRY(system_call)
stg %r14,__PT_FLAGS(%r11)
.Lsysc_do_svc:
# load address of system call table
#ifdef CONFIG_HAVE_MARCH_Z990_FEATURES
lg %r10,__TASK_thread+__THREAD_sysc_table(%r12)
#else
lghi %r13,__TASK_thread
lg %r10,__THREAD_sysc_table(%r13,%r12)
#endif
llgh %r8,__PT_INT_CODE+2(%r11)
slag %r8,%r8,2 # shift and test for svc 0
jnz .Lsysc_nr_ok
......@@ -508,8 +489,7 @@ ENTRY(pgm_check_handler)
1: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j 3f
2: LAST_BREAK %r14
UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
2: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
lg %r15,__LC_KERNEL_STACK
lgr %r14,%r12
aghi %r14,__TASK_thread # pointer to thread_struct
......@@ -518,6 +498,7 @@ ENTRY(pgm_check_handler)
jz 3f
mvc __THREAD_trap_tdb(256,%r14),0(%r13)
3: la %r11,STACK_FRAME_OVERHEAD(%r15)
stg %r10,__THREAD_last_break(%r14)
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
stmg %r8,%r9,__PT_PSW(%r11)
......@@ -576,7 +557,6 @@ ENTRY(io_int_handler)
STCK __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_CURRENT
larl %r13,cleanup_critical
lmg %r8,%r9,__LC_IO_OLD_PSW
......@@ -750,7 +730,6 @@ ENTRY(ext_int_handler)
STCK __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_CURRENT
larl %r13,cleanup_critical
lmg %r8,%r9,__LC_EXT_OLD_PSW
......@@ -893,7 +872,6 @@ ENTRY(mcck_int_handler)
la %r1,4095 # revalidate r1
spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # revalidate cpu timer
lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# revalidate gprs
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_CURRENT
larl %r13,cleanup_critical
lmg %r8,%r9,__LC_MCK_OLD_PSW
......@@ -1088,9 +1066,10 @@ cleanup_critical:
0: # check if base register setup + TIF bit load has been done
clg %r9,BASED(.Lcleanup_system_call_insn+16)
jhe 0f
# set up saved registers r10 and r12
stg %r10,16(%r11) # r10 last break
stg %r12,32(%r11) # r12 task struct pointer
# set up saved register r12 task struct pointer
stg %r12,32(%r11)
# set up saved register r13 __TASK_thread offset
mvc 40(8,%r11),BASED(.Lcleanup_system_call_const)
0: # check if the user time update has been done
clg %r9,BASED(.Lcleanup_system_call_insn+24)
jh 0f
......@@ -1107,14 +1086,7 @@ cleanup_critical:
stg %r15,__LC_SYSTEM_TIMER
0: # update accounting time stamp
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
# do LAST_BREAK
lg %r9,16(%r11)
srag %r9,%r9,23
jz 0f
lgr %r9,%r12
aghi %r9,__TASK_thread
mvc __THREAD_last_break(8,%r9),16(%r11)
0: # set up saved register r11
# set up saved register r11
lg %r15,__LC_KERNEL_STACK
la %r9,STACK_FRAME_OVERHEAD(%r15)
stg %r9,24(%r11) # r11 pt_regs pointer
......@@ -1136,6 +1108,8 @@ cleanup_critical:
.quad .Lsysc_per
.quad .Lsysc_vtime+36
.quad .Lsysc_vtime+42
.Lcleanup_system_call_const:
.quad __TASK_thread
.Lcleanup_sysc_tif:
larl %r9,.Lsysc_tif
......
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