2002-11-09 Heiko Carstens <heiko.carstens@de.ibm.com>

        Bugfix for s390/s390x:
        * syscall.c: Fixed scno derivation for s390/s390x.

diff --git a/ChangeLog b/ChangeLog
index 09a12c928c8268bb94d1a4cf829de5de2f11201b..19da216e736be0421ce655fc63ef4dd0fd42ba8c 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2002-11-09  Heiko Carstens <heiko.carstens@de.ibm.com>
+
+       Bugfix for s390/s390x:
+       * syscall.c: Fixed scno derivation for s390/s390x.
+
 2002-11-06  Michal Ludvig  <mludvig@suse.cz>
 
        Merged patch from Steven J. Hill <sjhill@realitydiluted.com>
@@ -6,7 +11,7 @@
 2002-11-06  Michal Ludvig  <mludvig@suse.cz>
 
        From Marty Leisner <leisner@rochester.rr.com>, 
-       rewritten my mludvig:
+       rewritten by mludvig:
        * strace.c (not_failing_only): New.
        (usage): Added -z switch description.
        (main): Added -z switch parsing to not_failing_only variable.

diff --git a/syscall.c b/syscall.c
index 1f98de012d4e33c115e9703c2e0026d38439077b..19802ccfdd4506dae14c233d35da9e529c98d916 100644 (file)
--- a/syscall.c
+++ b/syscall.c
@@ -683,6 +683,7 @@ struct tcb *tcp;
 #elif defined(S390) || defined(S390X)
        static long gpr2;
        static long pc;
+       static long syscall_mode;
 #elif defined(HPPA)
        static long r28;
 #elif defined(SH)
@@ -707,12 +708,83 @@ struct tcb *tcp;
 
 #ifdef LINUX
 #if defined(S390) || defined(S390X)
-       if (upeek(pid,PT_PSWADDR,&pc) < 0)
+       if (upeek(pid, PT_GPR2, &syscall_mode) < 0)
                return -1;
-       scno = ptrace(PTRACE_PEEKTEXT, pid, (char *)(pc-sizeof(long)),0);
-       if (errno)
-               return -1;
-       scno&=0xFF;
+       if (syscall_mode != -ENOSYS){
+               /*
+                * Since kernel version 2.5.44 the scno gets passed in gpr2.
+                */
+               scno = syscall_mode;
+       }
+       else {
+               /*
+                * Old style of "passing" the scno via the SVC instruction.
+                */
+
+               long opcode, offset_reg, tmp;
+               void * svc_addr;
+               int gpr_offset[16] = {PT_GPR0,  PT_GPR1,  PT_ORIGGPR2, PT_GPR3,
+                                     PT_GPR4,  PT_GPR5,  PT_GPR6,     PT_GPR7,
+                                     PT_GPR8,  PT_GPR9,  PT_GPR10,    PT_GPR11,
+                                     PT_GPR12, PT_GPR13, PT_GPR14,    PT_GPR15};
+         
+               if (upeek(pid, PT_PSWADDR, &pc) < 0)
+                       return -1;
+               opcode = ptrace(PTRACE_PEEKTEXT, pid, (char *)(pc-sizeof(long)), 0);
+               if (errno)
+                       return -1;
+
+               /*
+                *  We have to check if the SVC got executed directly or via an
+                *  EXECUTE instruction. In case of EXECUTE it is necessary to do
+                *  instruction decoding to derive the system call number.
+                *  Unfortunately the opcode sizes of EXECUTE and SVC are differently,
+                *  so that this doesn't work if a SVC opcode is part of an EXECUTE
+                *  opcode. Since there is no way to find out the opcode size this
+                *  is the best we can do...
+                */
+
+               if ((opcode & 0xff00) == 0x0a00) {
+                       /* SVC opcode */
+                       scno = opcode & 0xff;
+               } 
+               else {
+                       /* SVC got executed by EXECUTE instruction */
+
+                       /*
+                        *  Do instruction decoding of EXECUTE. If you really want to
+                        *  understand this, read the Principles of Operations.
+                        */
+                       svc_addr = (void *) (opcode & 0xfff);
+
+                       tmp = 0;
+                       offset_reg = (opcode & 0x000f0000) >> 16;
+                       if (offset_reg && (upeek(pid, gpr_offset[offset_reg], &tmp) < 0))
+                               return -1;
+                       svc_addr += tmp;
+
+                       tmp = 0;
+                       offset_reg = (opcode & 0x0000f000) >> 12;
+                       if (offset_reg && (upeek(pid, gpr_offset[offset_reg], &tmp) < 0))
+                               return -1;
+                       svc_addr += tmp;
+
+                       scno = ptrace(PTRACE_PEEKTEXT, pid, svc_addr, 0);
+                       if (errno)
+                               return -1;
+#if defined(S390X)
+                       scno >>= 48;
+#else
+                       scno >>= 16;
+#endif
+                       tmp = 0;
+                       offset_reg = (opcode & 0x00f00000) >> 20;
+                       if (offset_reg && (upeek(pid, gpr_offset[offset_reg], &tmp) < 0))
+                               return -1;
+
+                       scno = (scno | tmp) & 0xff;
+               }
+       }
 #elif defined (POWERPC)
        if (upeek(pid, 4*PT_R0, &scno) < 0)
                return -1;
@@ -1102,7 +1174,9 @@ struct tcb *tcp;
 #elif defined (S390) || defined (S390X)
        if (upeek(pid, PT_GPR2, &gpr2) < 0)
                return -1;
-       if (gpr2 != -ENOSYS && !(tcp->flags & TCB_INSYSCALL)) {
+       if (syscall_mode != -ENOSYS)
+               syscall_mode = tcp->scno;
+       if (gpr2 != syscall_mode && !(tcp->flags & TCB_INSYSCALL)) {
                if (debug)
                        fprintf(stderr, "stray syscall exit: gpr2 = %ld\n", gpr2);
                return 0;