[S390] signal race with restarting system calls

[mirror_ubuntu-zesty-kernel.git] / arch / s390 / kernel / entry.S

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 195387ab7c983ca42496c2f8ca927a4176a05b13..afe3685d30e799b27e4018b4f28ed7a14037342e 100644 (file)
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -43,8 +43,7 @@ SP_R13             =  STACK_FRAME_OVERHEAD + __PT_GPRS + 52
 SP_R14      =  STACK_FRAME_OVERHEAD + __PT_GPRS + 56
 SP_R15      =  STACK_FRAME_OVERHEAD + __PT_GPRS + 60
 SP_ORIG_R2   = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
-SP_ILC      =  STACK_FRAME_OVERHEAD + __PT_ILC
-SP_SVCNR     = STACK_FRAME_OVERHEAD + __PT_SVCNR
+SP_SVC_CODE  = STACK_FRAME_OVERHEAD + __PT_SVC_CODE
 SP_SIZE      = STACK_FRAME_OVERHEAD + __PT_SIZE
 
 _TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
@@ -229,7 +228,7 @@ sysc_saveall:
        SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA
        CREATE_STACK_FRAME __LC_SAVE_AREA
        mvc     SP_PSW(8,%r15),__LC_SVC_OLD_PSW
-       mvc     SP_ILC(4,%r15),__LC_SVC_ILC
+       mvc     SP_SVC_CODE(4,%r15),__LC_SVC_ILC
        l       %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
 sysc_vtime:
        UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER
@@ -239,12 +238,12 @@ sysc_update:
        mvc     __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
 sysc_do_svc:
        xr      %r7,%r7
-       icm     %r7,3,SP_SVCNR(%r15)    # load svc number and test for svc 0
+       icm     %r7,3,SP_SVC_CODE+2(%r15)# load svc number and test for svc 0
        bnz     BASED(sysc_nr_ok)       # svc number > 0
        # svc 0: system call number in %r1
        cl      %r1,BASED(.Lnr_syscalls)
        bnl     BASED(sysc_nr_ok)
-       sth     %r1,SP_SVCNR(%r15)
+       sth     %r1,SP_SVC_CODE+2(%r15)
        lr      %r7,%r1           # copy svc number to %r7
 sysc_nr_ok:
        sll     %r7,2             # svc number *4
@@ -335,10 +334,11 @@ sysc_notify_resume:
 #
 sysc_restart:
        ni      __TI_flags+3(%r12),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
-       l       %r7,SP_R2(%r15)         # load new svc number
-       mvc     SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument
        lm      %r2,%r6,SP_R2(%r15)     # load svc arguments
-       sth     %r7,SP_SVCNR(%r15)
+       xr      %r7,%r7                 # svc 0 returns -ENOSYS
+       clc     SP_SVC_CODE+2(%r15),BASED(.Lnr_syscalls+2)
+       bnl     BASED(sysc_nr_ok)       # invalid svc number -> do svc 0
+       icm     %r7,3,SP_SVC_CODE+2(%r15)# load new svc number
        b       BASED(sysc_nr_ok)       # restart svc
 
 #
@@ -346,7 +346,7 @@ sysc_restart:
 #
 sysc_singlestep:
        ni      __TI_flags+3(%r12),255-_TIF_PER_TRAP # clear TIF_PER_TRAP
-       xc      SP_SVCNR(2,%r15),SP_SVCNR(%r15)         # clear svc number
+       xc      SP_SVC_CODE(4,%r15),SP_SVC_CODE(%r15)   # clear svc code
        la      %r2,SP_PTREGS(%r15)     # address of register-save area
        l       %r1,BASED(.Lhandle_per) # load adr. of per handler
        la      %r14,BASED(sysc_return) # load adr. of system return
@@ -361,7 +361,7 @@ sysc_tracesys:
        la      %r2,SP_PTREGS(%r15)     # load pt_regs
        la      %r3,0
        xr      %r0,%r0
-       icm     %r0,3,SP_SVCNR(%r15)
+       icm     %r0,3,SP_SVC_CODE(%r15)
        st      %r0,SP_R2(%r15)
        basr    %r14,%r1
        cl      %r2,BASED(.Lnr_syscalls)
@@ -454,7 +454,7 @@ ENTRY(pgm_check_handler)
        bnz     BASED(pgm_per)          # got per exception -> special case
        SAVE_ALL_PGM __LC_PGM_OLD_PSW,__LC_SAVE_AREA
        CREATE_STACK_FRAME __LC_SAVE_AREA
-       xc      SP_ILC(4,%r15),SP_ILC(%r15)
+       xc      SP_SVC_CODE(4,%r15),SP_SVC_CODE(%r15)
        mvc     SP_PSW(8,%r15),__LC_PGM_OLD_PSW
        l       %r12,__LC_THREAD_INFO   # load pointer to thread_info struct
        tm      SP_PSW+1(%r15),0x01     # interrupting from user ?
@@ -531,7 +531,7 @@ pgm_svcper:
        SAVE_ALL_PGM __LC_SVC_OLD_PSW,__LC_SAVE_AREA
        CREATE_STACK_FRAME __LC_SAVE_AREA
        mvc     SP_PSW(8,%r15),__LC_SVC_OLD_PSW
-       mvc     SP_ILC(4,%r15),__LC_SVC_ILC
+       mvc     SP_SVC_CODE(4,%r15),__LC_SVC_ILC
        l       %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
@@ -550,7 +550,7 @@ pgm_svcper:
 #
 kernel_per:
        REENABLE_IRQS
-       xc      SP_SVCNR(2,%r15),SP_SVCNR(%r15)
+       xc      SP_SVC_CODE(4,%r15),SP_SVC_CODE(%r15)
        la      %r2,SP_PTREGS(%r15)     # address of register-save area
        l       %r1,BASED(.Lhandle_per) # load adr. of per handler
        basr    %r14,%r1                # branch to do_single_step
@@ -966,7 +966,7 @@ cleanup_system_call:
        st      %r15,12(%r12)
        CREATE_STACK_FRAME __LC_SAVE_AREA
        mvc     SP_PSW(8,%r15),__LC_SVC_OLD_PSW
-       mvc     SP_ILC(4,%r15),__LC_SVC_ILC
+       mvc     SP_SVC_CODE(4,%r15),__LC_SVC_ILC
        mvc     0(4,%r12),__LC_THREAD_INFO
 cleanup_vtime:
        clc     __LC_RETURN_PSW+4(4),BASED(cleanup_system_call_insn+12)