[S390] add breaking event address for user space

Copy the last breaking event address from the lowcore to a new
field in the thread_struct on each system entry. Add a new
ptrace request PTRACE_GET_LAST_BREAK and a new utrace regset
REGSET_LAST_BREAK to query the last breaking event.

This is useful for debugging wild branches in user space code.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index fef9b33..e2c218d 100644 (file)
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -328,8 +328,8 @@ struct pt_regs
        psw_t psw;
        unsigned long gprs[NUM_GPRS];
        unsigned long orig_gpr2;
-       unsigned short svcnr;
        unsigned short ilc;
+       unsigned short svcnr;
 };
 #endif
 
@@ -436,6 +436,7 @@ typedef struct
 #define PTRACE_PEEKDATA_AREA         0x5003
 #define PTRACE_POKETEXT_AREA         0x5004
 #define PTRACE_POKEDATA_AREA         0x5005
+#define PTRACE_GET_LAST_BREAK        0x5006
 
 /*
  * PT_PROT definition is loosely based on hppa bsd definition in

diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 34f0873..be3d3f9 100644 (file)
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -50,6 +50,7 @@ struct thread_info {
        struct restart_block    restart_block;
        __u64                   user_timer;
        __u64                   system_timer;
+       unsigned long           last_break;     /* last breaking-event-address. */
 };
 
 /*

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 44a4336..d9b490a 100644 (file)
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -39,6 +39,7 @@ int main(void)
        DEFINE(__TI_precount, offsetof(struct thread_info, preempt_count));
        DEFINE(__TI_user_timer, offsetof(struct thread_info, user_timer));
        DEFINE(__TI_system_timer, offsetof(struct thread_info, system_timer));
+       DEFINE(__TI_last_break, offsetof(struct thread_info, last_break));
        BLANK();
        DEFINE(__PT_ARGS, offsetof(struct pt_regs, args));
        DEFINE(__PT_PSW, offsetof(struct pt_regs, psw));

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 0e2b162..d5e3e60 100644 (file)
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -180,9 +180,9 @@ STACK_SIZE  = 1 << STACK_SHIFT
        s       %r15,BASED(.Lc_spsize)  # make room for registers & psw
        mvc     SP_PSW(8,%r15),0(%r12)  # move user PSW to stack
        st      %r2,SP_ORIG_R2(%r15)    # store original content of gpr 2
-       icm     %r12,3,__LC_SVC_ILC
+       icm     %r12,12,__LC_SVC_ILC
        stm     %r0,%r11,SP_R0(%r15)    # store gprs %r0-%r11 to kernel stack
-       st      %r12,SP_SVCNR(%r15)
+       st      %r12,SP_ILC(%r15)
        mvc     SP_R12(16,%r15),\savearea # move %r12-%r15 to stack
        la      %r12,0
        st      %r12,__SF_BACKCHAIN(%r15)       # clear back chain

diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 829b759..178d925 100644 (file)
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -126,31 +126,35 @@ _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
  *    R15 - kernel stack pointer
  */
 
-       .macro  SAVE_ALL_BASE savearea
-       stmg    %r12,%r15,\savearea
-       larl    %r13,system_call
-       .endm
-
        .macro  SAVE_ALL_SVC psworg,savearea
-       la      %r12,\psworg
+       stmg    %r11,%r15,\savearea
        lg      %r15,__LC_KERNEL_STACK  # problem state -> load ksp
+       aghi    %r15,-SP_SIZE           # make room for registers & psw
+       lg      %r11,__LC_LAST_BREAK
        .endm
 
-       .macro  SAVE_ALL_SYNC psworg,savearea
-       la      %r12,\psworg
+       .macro  SAVE_ALL_PGM psworg,savearea
+       stmg    %r11,%r15,\savearea
        tm      \psworg+1,0x01          # test problem state bit
-       jz      2f                      # skip stack setup save
-       lg      %r15,__LC_KERNEL_STACK  # problem state -> load ksp
 #ifdef CONFIG_CHECK_STACK
-       j       3f
-2:     tml     %r15,STACK_SIZE - CONFIG_STACK_GUARD
-       jz      stack_overflow
-3:
+       jnz     1f
+       tml     %r15,STACK_SIZE - CONFIG_STACK_GUARD
+       jnz     2f
+       la      %r12,\psworg
+       j       stack_overflow
+#else
+       jz      2f
 #endif
-2:
+1:     lg      %r15,__LC_KERNEL_STACK  # problem state -> load ksp
+2:     aghi    %r15,-SP_SIZE           # make room for registers & psw
+       larl    %r13,system_call
+       lg      %r11,__LC_LAST_BREAK
        .endm
 
        .macro  SAVE_ALL_ASYNC psworg,savearea
+       stmg    %r11,%r15,\savearea
+       larl    %r13,system_call
+       lg      %r11,__LC_LAST_BREAK
        la      %r12,\psworg
        tm      \psworg+1,0x01          # test problem state bit
        jnz     1f                      # from user -> load kernel stack
@@ -164,27 +168,23 @@ _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
 0:     lg      %r14,__LC_ASYNC_STACK   # are we already on the async. stack ?
        slgr    %r14,%r15
        srag    %r14,%r14,STACK_SHIFT
-       jz      2f
-1:     lg      %r15,__LC_ASYNC_STACK   # load async stack
 #ifdef CONFIG_CHECK_STACK
-       j       3f
-2:     tml     %r15,STACK_SIZE - CONFIG_STACK_GUARD
-       jz      stack_overflow
-3:
+       jnz     1f
+       tml     %r15,STACK_SIZE - CONFIG_STACK_GUARD
+       jnz     2f
+       j       stack_overflow
+#else
+       jz      2f
 #endif
-2:
+1:     lg      %r15,__LC_ASYNC_STACK   # load async stack
+2:     aghi    %r15,-SP_SIZE           # make room for registers & psw
        .endm
 
-       .macro  CREATE_STACK_FRAME psworg,savearea
-       aghi    %r15,-SP_SIZE           # make room for registers & psw
-       mvc     SP_PSW(16,%r15),0(%r12) # move user PSW to stack
+       .macro  CREATE_STACK_FRAME savearea
+       xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
        stg     %r2,SP_ORIG_R2(%r15)    # store original content of gpr 2
-       icm     %r12,3,__LC_SVC_ILC
-       stmg    %r0,%r11,SP_R0(%r15)    # store gprs %r0-%r11 to kernel stack
-       st      %r12,SP_SVCNR(%r15)
-       mvc     SP_R12(32,%r15),\savearea # move %r12-%r15 to stack
-       la      %r12,0
-       stg     %r12,__SF_BACKCHAIN(%r15)
+       mvc     SP_R11(40,%r15),\savearea # move %r11-%r15 to stack
+       stmg    %r0,%r10,SP_R0(%r15)    # store gprs %r0-%r10 to kernel stack
        .endm
 
        .macro  RESTORE_ALL psworg,sync
@@ -200,6 +200,13 @@ _TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
        lpswe   \psworg                 # back to caller
        .endm
 
+       .macro  LAST_BREAK
+       srag    %r10,%r11,23
+       jz      0f
+       stg     %r11,__TI_last_break(%r12)
+0:
+       .endm
+
 /*
  * Scheduler resume function, called by switch_to
  *  gpr2 = (task_struct *) prev
@@ -245,37 +252,38 @@ __critical_start:
 system_call:
        stpt    __LC_SYNC_ENTER_TIMER
 sysc_saveall:
-       SAVE_ALL_BASE __LC_SAVE_AREA
        SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
-       CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
-       llgh    %r7,__LC_SVC_INT_CODE   # get svc number from lowcore
+       CREATE_STACK_FRAME __LC_SAVE_AREA
+       mvc     SP_PSW(16,%r15),__LC_SVC_OLD_PSW
+       mvc     SP_ILC(4,%r15),__LC_SVC_ILC
+       stg     %r7,SP_ARGS(%r15)
+       lg      %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
 sysc_vtime:
        UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
 sysc_stime:
        UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 sysc_update:
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+       LAST_BREAK
 sysc_do_svc:
-       lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
-       ltgr    %r7,%r7         # test for svc 0
+       llgh    %r7,SP_SVCNR(%r15)
+       slag    %r7,%r7,2       # shift and test for svc 0
        jnz     sysc_nr_ok
        # svc 0: system call number in %r1
-       cl      %r1,BASED(.Lnr_syscalls)
+       llgfr   %r1,%r1         # clear high word in r1
+       cghi    %r1,NR_syscalls
        jnl     sysc_nr_ok
-       lgfr    %r7,%r1         # clear high word in r1
+       sth     %r1,SP_SVCNR(%r15)
+       slag    %r7,%r1,2       # shift and test for svc 0
 sysc_nr_ok:
-       mvc     SP_ARGS(8,%r15),SP_R7(%r15)
-sysc_do_restart:
-       sth     %r7,SP_SVCNR(%r15)
-       sllg    %r7,%r7,2       # svc number * 4
        larl    %r10,sys_call_table
 #ifdef CONFIG_COMPAT
-       tm      __TI_flags+5(%r9),(_TIF_31BIT>>16)  # running in 31 bit mode ?
+       tm      __TI_flags+5(%r12),(_TIF_31BIT>>16)  # running in 31 bit mode ?
        jno     sysc_noemu
        larl    %r10,sys_call_table_emu  # use 31 bit emulation system calls
 sysc_noemu:
 #endif
-       tm      __TI_flags+6(%r9),_TIF_SYSCALL
+       tm      __TI_flags+6(%r12),_TIF_SYSCALL
        lgf     %r8,0(%r7,%r10) # load address of system call routine
        jnz     sysc_tracesys
        basr    %r14,%r8        # call sys_xxxx
@@ -284,7 +292,7 @@ sysc_noemu:
 sysc_return:
        LOCKDEP_SYS_EXIT
 sysc_tif:
-       tm      __TI_flags+7(%r9),_TIF_WORK_SVC
+       tm      __TI_flags+7(%r12),_TIF_WORK_SVC
        jnz     sysc_work       # there is work to do (signals etc.)
 sysc_restore:
        RESTORE_ALL __LC_RETURN_PSW,1
@@ -301,17 +309,17 @@ sysc_work:
 # One of the work bits is on. Find out which one.
 #
 sysc_work_tif:
-       tm      __TI_flags+7(%r9),_TIF_MCCK_PENDING
+       tm      __TI_flags+7(%r12),_TIF_MCCK_PENDING
        jo      sysc_mcck_pending
-       tm      __TI_flags+7(%r9),_TIF_NEED_RESCHED
+       tm      __TI_flags+7(%r12),_TIF_NEED_RESCHED
        jo      sysc_reschedule
-       tm      __TI_flags+7(%r9),_TIF_SIGPENDING
+       tm      __TI_flags+7(%r12),_TIF_SIGPENDING
        jo      sysc_sigpending
-       tm      __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
+       tm      __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
        jo      sysc_notify_resume
-       tm      __TI_flags+7(%r9),_TIF_RESTART_SVC
+       tm      __TI_flags+7(%r12),_TIF_RESTART_SVC
        jo      sysc_restart
-       tm      __TI_flags+7(%r9),_TIF_SINGLE_STEP
+       tm      __TI_flags+7(%r12),_TIF_SINGLE_STEP
        jo      sysc_singlestep
        j       sysc_return             # beware of critical section cleanup
 
@@ -333,12 +341,12 @@ sysc_mcck_pending:
 # _TIF_SIGPENDING is set, call do_signal
 #
 sysc_sigpending:
-       ni      __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
+       ni      __TI_flags+7(%r12),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
        la      %r2,SP_PTREGS(%r15)     # load pt_regs
        brasl   %r14,do_signal          # call do_signal
-       tm      __TI_flags+7(%r9),_TIF_RESTART_SVC
+       tm      __TI_flags+7(%r12),_TIF_RESTART_SVC
        jo      sysc_restart
-       tm      __TI_flags+7(%r9),_TIF_SINGLE_STEP
+       tm      __TI_flags+7(%r12),_TIF_SINGLE_STEP
        jo      sysc_singlestep
        j       sysc_return
 
@@ -354,17 +362,19 @@ sysc_notify_resume:
 # _TIF_RESTART_SVC is set, set up registers and restart svc
 #
 sysc_restart:
-       ni      __TI_flags+7(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
+       ni      __TI_flags+7(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
        lg      %r7,SP_R2(%r15)         # load new svc number
        mvc     SP_R2(8,%r15),SP_ORIG_R2(%r15) # restore first argument
        lmg     %r2,%r6,SP_R2(%r15)     # load svc arguments
-       j       sysc_do_restart         # restart svc
+       sth     %r7,SP_SVCNR(%r15)
+       slag    %r7,%r7,2
+       j       sysc_nr_ok              # restart svc
 
 #
 # _TIF_SINGLE_STEP is set, call do_single_step
 #
 sysc_singlestep:
-       ni      __TI_flags+7(%r9),255-_TIF_SINGLE_STEP  # clear TIF_SINGLE_STEP
+       ni      __TI_flags+7(%r12),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
        xc      SP_SVCNR(2,%r15),SP_SVCNR(%r15)         # clear svc number
        la      %r2,SP_PTREGS(%r15)     # address of register-save area
        larl    %r14,sysc_return        # load adr. of system return
@@ -377,8 +387,8 @@ sysc_singlestep:
 sysc_tracesys:
        la      %r2,SP_PTREGS(%r15)     # load pt_regs
        la      %r3,0
-       srl     %r7,2
-       stg     %r7,SP_R2(%r15)
+       llgh    %r0,SP_SVCNR(%r15)
+       stg     %r0,SP_R2(%r15)
        brasl   %r14,do_syscall_trace_enter
        lghi    %r0,NR_syscalls
        clgr    %r0,%r2
@@ -391,7 +401,7 @@ sysc_tracego:
        basr    %r14,%r8                # call sys_xxx
        stg     %r2,SP_R2(%r15)         # store return value
 sysc_tracenogo:
-       tm      __TI_flags+6(%r9),_TIF_SYSCALL
+       tm      __TI_flags+6(%r12),_TIF_SYSCALL
        jz      sysc_return
        la      %r2,SP_PTREGS(%r15)     # load pt_regs
        larl    %r14,sysc_return        # return point is sysc_return
@@ -403,7 +413,7 @@ sysc_tracenogo:
        .globl  ret_from_fork
 ret_from_fork:
        lg      %r13,__LC_SVC_NEW_PSW+8
-       lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
+       lg      %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
        tm      SP_PSW+1(%r15),0x01     # forking a kernel thread ?
        jo      0f
        stg     %r15,SP_R15(%r15)       # store stack pointer for new kthread
@@ -437,8 +447,8 @@ kernel_execve:
        lg      %r15,__LC_KERNEL_STACK  # load ksp
        aghi    %r15,-SP_SIZE           # make room for registers & psw
        lg      %r13,__LC_SVC_NEW_PSW+8
-       lg      %r9,__LC_THREAD_INFO
        mvc     SP_PTREGS(__PT_SIZE,%r15),0(%r12)       # copy pt_regs
+       lg      %r12,__LC_THREAD_INFO
        xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 #      TRACE_IRQS_ON
        stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
@@ -465,21 +475,23 @@ pgm_check_handler:
  * for LPSW?).
  */
        stpt    __LC_SYNC_ENTER_TIMER
-       SAVE_ALL_BASE __LC_SAVE_AREA
        tm      __LC_PGM_INT_CODE+1,0x80 # check whether we got a per exception
        jnz     pgm_per                  # got per exception -> special case
-       SAVE_ALL_SYNC __LC_PGM_OLD_PSW,__LC_SAVE_AREA
-       CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
+       SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
+       CREATE_STACK_FRAME __LC_SAVE_AREA
+       xc      SP_ILC(4,%r15),SP_ILC(%r15)
+       mvc     SP_PSW(16,%r15),__LC_PGM_OLD_PSW
+       lg      %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
        tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
        jz      pgm_no_vtime
        UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
        UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+       LAST_BREAK
 pgm_no_vtime:
        HANDLE_SIE_INTERCEPT
        TRACE_IRQS_CHECK_OFF
-       lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
-       mvc     SP_ARGS(8,%r15),__LC_LAST_BREAK
+       stg     %r11,SP_ARGS(%r15)
        lgf     %r3,__LC_PGM_ILC        # load program interruption code
        lghi    %r8,0x7f
        ngr     %r8,%r3
@@ -503,31 +515,32 @@ pgm_per:
        clc     __LC_PGM_OLD_PSW(16),__LC_SVC_NEW_PSW
        je      pgm_svcper
 # no interesting special case, ignore PER event
-       lmg     %r12,%r15,__LC_SAVE_AREA
        lpswe   __LC_PGM_OLD_PSW
 
 #
 # Normal per exception
 #
 pgm_per_std:
-       SAVE_ALL_SYNC __LC_PGM_OLD_PSW,__LC_SAVE_AREA
-       CREATE_STACK_FRAME __LC_PGM_OLD_PSW,__LC_SAVE_AREA
+       SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
+       CREATE_STACK_FRAME __LC_SAVE_AREA
+       mvc     SP_PSW(16,%r15),__LC_PGM_OLD_PSW
+       lg      %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
        tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
        jz      pgm_no_vtime2
        UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
        UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
+       LAST_BREAK
 pgm_no_vtime2:
        HANDLE_SIE_INTERCEPT
        TRACE_IRQS_CHECK_OFF
-       lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
-       lg      %r1,__TI_task(%r9)
+       lg      %r1,__TI_task(%r12)
        tm      SP_PSW+1(%r15),0x01     # kernel per event ?
        jz      kernel_per
        mvc     __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
        mvc     __THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
        mvc     __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
-       oi      __TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+       oi      __TI_flags+7(%r12),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
        lgf     %r3,__LC_PGM_ILC        # load program interruption code
        lghi    %r8,0x7f
        ngr     %r8,%r3                 # clear per-event-bit and ilc
@@ -538,19 +551,21 @@ pgm_no_vtime2:
 # it was a single stepped SVC that is causing all the trouble
 #
 pgm_svcper:
-       SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
-       CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
+       SAVE_ALL_PGM __LC_SVC_OLD_PSW,__LC_SAVE_AREA
+       CREATE_STACK_FRAME __LC_SAVE_AREA
+       mvc     SP_PSW(16,%r15),__LC_SVC_OLD_PSW
+       mvc     SP_ILC(4,%r15),__LC_SVC_ILC
+       lg      %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
        UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
        UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
-       llgh    %r7,__LC_SVC_INT_CODE   # get svc number from lowcore
-       lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
+       LAST_BREAK
        TRACE_IRQS_OFF
-       lg      %r8,__TI_task(%r9)
+       lg      %r8,__TI_task(%r12)
        mvc     __THREAD_per+__PER_atmid(2,%r8),__LC_PER_ATMID
        mvc     __THREAD_per+__PER_address(8,%r8),__LC_PER_ADDRESS
        mvc     __THREAD_per+__PER_access_id(1,%r8),__LC_PER_ACCESS_ID
-       oi      __TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
+       oi      __TI_flags+7(%r12),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
        TRACE_IRQS_ON
        stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
        lmg     %r2,%r6,SP_R2(%r15)     # load svc arguments
@@ -572,16 +587,17 @@ kernel_per:
 io_int_handler:
        stck    __LC_INT_CLOCK
        stpt    __LC_ASYNC_ENTER_TIMER
-       SAVE_ALL_BASE __LC_SAVE_AREA+32
-       SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+32
-       CREATE_STACK_FRAME __LC_IO_OLD_PSW,__LC_SAVE_AREA+32
+       SAVE_ALL_ASYNC __LC_IO_OLD_PSW,__LC_SAVE_AREA+40
+       CREATE_STACK_FRAME __LC_SAVE_AREA+40
+       mvc     SP_PSW(16,%r15),0(%r12) # move user PSW to stack
+       lg      %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
        tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
        jz      io_no_vtime
        UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
        UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+       LAST_BREAK
 io_no_vtime:
-       lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
        HANDLE_SIE_INTERCEPT
        TRACE_IRQS_OFF
        la      %r2,SP_PTREGS(%r15)     # address of register-save area
@@ -590,7 +606,7 @@ io_return:
        LOCKDEP_SYS_EXIT
        TRACE_IRQS_ON
 io_tif:
-       tm      __TI_flags+7(%r9),_TIF_WORK_INT
+       tm      __TI_flags+7(%r12),_TIF_WORK_INT
        jnz     io_work                 # there is work to do (signals etc.)
 io_restore:
        RESTORE_ALL __LC_RETURN_PSW,0
@@ -610,7 +626,7 @@ io_work:
        jo      io_work_user            # yes -> do resched & signal
 #ifdef CONFIG_PREEMPT
        # check for preemptive scheduling
-       icm     %r0,15,__TI_precount(%r9)
+       icm     %r0,15,__TI_precount(%r12)
        jnz     io_restore              # preemption is disabled
        tm      __TI_flags+7(%r12),_TIF_NEED_RESCHED
        jno     io_restore
@@ -645,13 +661,13 @@ io_work_user:
 #             and _TIF_MCCK_PENDING
 #
 io_work_tif:
-       tm      __TI_flags+7(%r9),_TIF_MCCK_PENDING
+       tm      __TI_flags+7(%r12),_TIF_MCCK_PENDING
        jo      io_mcck_pending
-       tm      __TI_flags+7(%r9),_TIF_NEED_RESCHED
+       tm      __TI_flags+7(%r12),_TIF_NEED_RESCHED
        jo      io_reschedule
-       tm      __TI_flags+7(%r9),_TIF_SIGPENDING
+       tm      __TI_flags+7(%r12),_TIF_SIGPENDING
        jo      io_sigpending
-       tm      __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
+       tm      __TI_flags+7(%r12),_TIF_NOTIFY_RESUME
        jo      io_notify_resume
        j       io_return               # beware of critical section cleanup
 
@@ -706,16 +722,17 @@ io_notify_resume:
 ext_int_handler:
        stck    __LC_INT_CLOCK
        stpt    __LC_ASYNC_ENTER_TIMER
-       SAVE_ALL_BASE __LC_SAVE_AREA+32
-       SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+32
-       CREATE_STACK_FRAME __LC_EXT_OLD_PSW,__LC_SAVE_AREA+32
+       SAVE_ALL_ASYNC __LC_EXT_OLD_PSW,__LC_SAVE_AREA+40
+       CREATE_STACK_FRAME __LC_SAVE_AREA+40
+       mvc     SP_PSW(16,%r15),0(%r12) # move user PSW to stack
+       lg      %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
        tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
        jz      ext_no_vtime
        UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER
        UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER
+       LAST_BREAK
 ext_no_vtime:
-       lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
        HANDLE_SIE_INTERCEPT
        TRACE_IRQS_OFF
        la      %r2,SP_PTREGS(%r15)     # address of register-save area
@@ -734,7 +751,9 @@ 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
-       SAVE_ALL_BASE __LC_SAVE_AREA+64
+       stmg    %r11,%r15,__LC_SAVE_AREA+80
+       larl    %r13,system_call
+       lg      %r11,__LC_LAST_BREAK
        la      %r12,__LC_MCK_OLD_PSW
        tm      __LC_MCCK_CODE,0x80     # system damage?
        jo      mcck_int_main           # yes -> rest of mcck code invalid
@@ -769,7 +788,10 @@ mcck_int_main:
        srag    %r14,%r14,PAGE_SHIFT
        jz      0f
        lg      %r15,__LC_PANIC_STACK   # load panic stack
-0:     CREATE_STACK_FRAME __LC_MCK_OLD_PSW,__LC_SAVE_AREA+64
+0:     aghi    %r15,-SP_SIZE           # make room for registers & psw
+       CREATE_STACK_FRAME __LC_SAVE_AREA+80
+       mvc     SP_PSW(16,%r15),0(%r12)
+       lg      %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
        tm      __LC_MCCK_CODE+2,0x08   # mwp of old psw valid?
        jno     mcck_no_vtime           # no -> no timer update
        tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
@@ -777,8 +799,8 @@ mcck_int_main:
        UPDATE_VTIME __LC_EXIT_TIMER,__LC_MCCK_ENTER_TIMER,__LC_USER_TIMER
        UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_MCCK_ENTER_TIMER
+       LAST_BREAK
 mcck_no_vtime:
-       lg      %r9,__LC_THREAD_INFO    # load pointer to thread_info struct
        la      %r2,SP_PTREGS(%r15)     # load pt_regs
        brasl   %r14,s390_do_machine_check
        tm      SP_PSW+1(%r15),0x01     # returning to user ?
@@ -789,7 +811,7 @@ mcck_no_vtime:
        xc      __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) # clear back chain
        lgr     %r15,%r1
        stosm   __SF_EMPTY(%r15),0x04   # turn dat on
-       tm      __TI_flags+7(%r9),_TIF_MCCK_PENDING
+       tm      __TI_flags+7(%r12),_TIF_MCCK_PENDING
        jno     mcck_return
        HANDLE_SIE_INTERCEPT
        TRACE_IRQS_OFF
@@ -803,6 +825,7 @@ mcck_return:
        jno     0f
        stpt    __LC_EXIT_TIMER
 0:     lpswe   __LC_RETURN_MCCK_PSW    # back to caller
+mcck_done:
 
 /*
  * Restart interruption handler, kick starter for additional CPUs
@@ -858,14 +881,14 @@ stack_overflow:
        lg      %r15,__LC_PANIC_STACK   # change to panic stack
        aghi    %r15,-SP_SIZE
        mvc     SP_PSW(16,%r15),0(%r12) # move user PSW to stack
-       stmg    %r0,%r11,SP_R0(%r15)    # store gprs %r0-%r11 to kernel stack
+       stmg    %r0,%r10,SP_R0(%r15)    # store gprs %r0-%r10 to kernel stack
        la      %r1,__LC_SAVE_AREA
        chi     %r12,__LC_SVC_OLD_PSW
        je      0f
        chi     %r12,__LC_PGM_OLD_PSW
        je      0f
-       la      %r1,__LC_SAVE_AREA+32
-0:     mvc     SP_R12(32,%r15),0(%r1)  # move %r12-%r15 to stack
+       la      %r1,__LC_SAVE_AREA+40
+0:     mvc     SP_R11(40,%r15),0(%r1)  # move %r11-%r15 to stack
        mvc     SP_ARGS(8,%r15),__LC_LAST_BREAK
        xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # clear back chain
        la      %r2,SP_PTREGS(%r15)     # load pt_regs
@@ -920,21 +943,23 @@ cleanup_system_call:
        je      0f
        mvc     __LC_SYNC_ENTER_TIMER(8),__LC_ASYNC_ENTER_TIMER
 0:     cghi    %r12,__LC_MCK_OLD_PSW
-       la      %r12,__LC_SAVE_AREA+64
+       la      %r12,__LC_SAVE_AREA+80
        je      0f
-       la      %r12,__LC_SAVE_AREA+32
+       la      %r12,__LC_SAVE_AREA+40
 0:     clc     __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+16)
        jhe     cleanup_vtime
        clc     __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn)
        jh      0f
-       mvc     __LC_SAVE_AREA(32),0(%r12)
-0:     stg     %r13,8(%r12)
-       stg     %r12,__LC_SAVE_AREA+96  # argh
-       SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
-       CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA
-       lg      %r12,__LC_SAVE_AREA+96  # argh
-       stg     %r15,24(%r12)
-       llgh    %r7,__LC_SVC_INT_CODE
+       mvc     __LC_SAVE_AREA(40),0(%r12)
+0:     lg      %r15,__LC_KERNEL_STACK  # problem state -> load ksp
+       aghi    %r15,-SP_SIZE           # make room for registers & psw
+       stg     %r15,32(%r12)
+       stg     %r11,0(%r12)
+       CREATE_STACK_FRAME __LC_SAVE_AREA
+       mvc     SP_PSW(16,%r15),__LC_SVC_OLD_PSW
+       mvc     SP_ILC(4,%r15),__LC_SVC_ILC
+       stg     %r7,SP_ARGS(%r15)
+       mvc     8(8,%r12),__LC_THREAD_INFO
 cleanup_vtime:
        clc     __LC_RETURN_PSW+8(8),BASED(cleanup_system_call_insn+24)
        jhe     cleanup_stime
@@ -945,7 +970,11 @@ cleanup_stime:
        UPDATE_VTIME __LC_LAST_UPDATE_TIMER,__LC_EXIT_TIMER,__LC_SYSTEM_TIMER
 cleanup_update:
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
-       mvc     __LC_RETURN_PSW+8(8),BASED(cleanup_table_system_call+8)
+       srag    %r12,%r11,23
+       lg      %r12,__LC_THREAD_INFO
+       jz      0f
+       stg     %r11,__TI_last_break(%r12)
+0:     mvc     __LC_RETURN_PSW+8(8),BASED(cleanup_table_system_call+8)
        la      %r12,__LC_RETURN_PSW
        br      %r14
 cleanup_system_call_insn:
@@ -972,11 +1001,11 @@ cleanup_sysc_restore:
        mvc     __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
 0:     mvc     __LC_RETURN_PSW(16),SP_PSW(%r15)
        cghi    %r12,__LC_MCK_OLD_PSW
-       la      %r12,__LC_SAVE_AREA+64
+       la      %r12,__LC_SAVE_AREA+80
        je      1f
-       la      %r12,__LC_SAVE_AREA+32
-1:     mvc     0(32,%r12),SP_R12(%r15)
-       lmg     %r0,%r11,SP_R0(%r15)
+       la      %r12,__LC_SAVE_AREA+40
+1:     mvc     0(40,%r12),SP_R11(%r15)
+       lmg     %r0,%r10,SP_R0(%r15)
        lg      %r15,SP_R15(%r15)
 2:     la      %r12,__LC_RETURN_PSW
        br      %r14
@@ -997,8 +1026,8 @@ cleanup_io_restore:
        jhe     0f
        mvc     __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
 0:     mvc     __LC_RETURN_PSW(16),SP_PSW(%r15)
-       mvc     __LC_SAVE_AREA+64(32),SP_R12(%r15)
-       lmg     %r0,%r11,SP_R0(%r15)
+       mvc     __LC_SAVE_AREA+80(40),SP_R11(%r15)
+       lmg     %r0,%r10,SP_R0(%r15)
        lg      %r15,SP_R15(%r15)
 1:     la      %r12,__LC_RETURN_PSW
        br      %r14
@@ -1010,13 +1039,6 @@ cleanup_io_restore_insn:
  * Integer constants
  */
                .align  4
-.Lconst:
-.Lnr_syscalls: .long   NR_syscalls
-.L0x0130:      .short  0x130
-.L0x0140:      .short  0x140
-.L0x0150:      .short  0x150
-.L0x0160:      .short  0x160
-.L0x0170:      .short  0x170
 .Lcritical_start:
                .quad   __critical_start
 .Lcritical_end:

diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 9f654da..83339d3 100644 (file)
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -57,6 +57,7 @@
 enum s390_regset {
        REGSET_GENERAL,
        REGSET_FP,
+       REGSET_LAST_BREAK,
        REGSET_GENERAL_EXTENDED,
 };
 
@@ -381,6 +382,10 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                        copied += sizeof(unsigned long);
                }
                return 0;
+       case PTRACE_GET_LAST_BREAK:
+               put_user(task_thread_info(child)->last_break,
+                        (unsigned long __user *) data);
+               return 0;
        default:
                /* Removing high order bit from addr (only for 31 bit). */
                addr &= PSW_ADDR_INSN;
@@ -633,6 +638,10 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
                        copied += sizeof(unsigned int);
                }
                return 0;
+       case PTRACE_GET_LAST_BREAK:
+               put_user(task_thread_info(child)->last_break,
+                        (unsigned int __user *) data);
+               return 0;
        }
        return compat_ptrace_request(child, request, addr, data);
 }
@@ -797,6 +806,28 @@ static int s390_fpregs_set(struct task_struct *target,
        return rc;
 }
 
+#ifdef CONFIG_64BIT
+
+static int s390_last_break_get(struct task_struct *target,
+                              const struct user_regset *regset,
+                              unsigned int pos, unsigned int count,
+                              void *kbuf, void __user *ubuf)
+{
+       if (count > 0) {
+               if (kbuf) {
+                       unsigned long *k = kbuf;
+                       *k = task_thread_info(target)->last_break;
+               } else {
+                       unsigned long  __user *u = ubuf;
+                       if (__put_user(task_thread_info(target)->last_break, u))
+                               return -EFAULT;
+               }
+       }
+       return 0;
+}
+
+#endif
+
 static const struct user_regset s390_regsets[] = {
        [REGSET_GENERAL] = {
                .core_note_type = NT_PRSTATUS,
@@ -814,6 +845,15 @@ static const struct user_regset s390_regsets[] = {
                .get = s390_fpregs_get,
                .set = s390_fpregs_set,
        },
+#ifdef CONFIG_64BIT
+       [REGSET_LAST_BREAK] = {
+               .core_note_type = NT_S390_LAST_BREAK,
+               .n = 1,
+               .size = sizeof(long),
+               .align = sizeof(long),
+               .get = s390_last_break_get,
+       },
+#endif
 };
 
 static const struct user_regset_view user_s390_view = {
@@ -948,6 +988,27 @@ static int s390_compat_regs_high_set(struct task_struct *target,
        return rc;
 }
 
+static int s390_compat_last_break_get(struct task_struct *target,
+                                     const struct user_regset *regset,
+                                     unsigned int pos, unsigned int count,
+                                     void *kbuf, void __user *ubuf)
+{
+       compat_ulong_t last_break;
+
+       if (count > 0) {
+               last_break = task_thread_info(target)->last_break;
+               if (kbuf) {
+                       unsigned long *k = kbuf;
+                       *k = last_break;
+               } else {
+                       unsigned long  __user *u = ubuf;
+                       if (__put_user(last_break, u))
+                               return -EFAULT;
+               }
+       }
+       return 0;
+}
+
 static const struct user_regset s390_compat_regsets[] = {
        [REGSET_GENERAL] = {
                .core_note_type = NT_PRSTATUS,
@@ -965,6 +1026,13 @@ static const struct user_regset s390_compat_regsets[] = {
                .get = s390_fpregs_get,
                .set = s390_fpregs_set,
        },
+       [REGSET_LAST_BREAK] = {
+               .core_note_type = NT_S390_LAST_BREAK,
+               .n = 1,
+               .size = sizeof(long),
+               .align = sizeof(long),
+               .get = s390_compat_last_break_get,
+       },
        [REGSET_GENERAL_EXTENDED] = {
                .core_note_type = NT_S390_HIGH_GPRS,
                .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),

diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 6289945..ee7ac8b 100644 (file)
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -313,6 +313,7 @@ static int setup_frame(int sig, struct k_sigaction *ka,
           To avoid breaking binary compatibility, they are passed as args. */
        regs->gprs[4] = current->thread.trap_no;
        regs->gprs[5] = current->thread.prot_addr;
+       regs->gprs[6] = task_thread_info(current)->last_break;
 
        /* Place signal number on stack to allow backtrace from handler.  */
        if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
@@ -376,6 +377,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
        regs->gprs[2] = map_signal(sig);
        regs->gprs[3] = (unsigned long) &frame->info;
        regs->gprs[4] = (unsigned long) &frame->uc;
+       regs->gprs[5] = task_thread_info(current)->last_break;
        return 0;
 
 give_sigsegv:

diff --git a/include/linux/elf.h b/include/linux/elf.h
index 5978584..4d60801 100644 (file)
--- a/include/linux/elf.h
+++ b/include/linux/elf.h
@@ -394,6 +394,7 @@ typedef struct elf64_shdr {
 #define NT_S390_TODPREG        0x303           /* s390 TOD programmable register */
 #define NT_S390_CTRS   0x304           /* s390 control registers */
 #define NT_S390_PREFIX 0x305           /* s390 prefix register */
+#define NT_S390_LAST_BREAK     0x306   /* s390 breaking event address */
 
 
 /* Note header in a PT_NOTE section */