Add state argument to change_syscall and fix SPARC

Add a state argument to change_syscall() so that SPARC can modify that
instead of read-modify-writing the whole register set.  This function is
always called within an arg_setup/arg_finish_change sequence which on
certain architectures like SPARC will also be doing a read-modify-write.
This prevents the second write (from arg_finish_change) from undoing the
effects of the change_syscall call.

* util.c (change_syscall): Move below definition of arg_setup_state.
Add state argument.
[SPARC || SPARC64] Change to set state->u_regs[U_REG_G1] rather than
read-modify-writing it with PTRACE_GETREGS and PTRACE_SETREGS.
(setbpt, clearbpt): Pass state argument to change_syscall.

Signed-off-by: James Hogan <james.hogan@imgtec.com>

diff --git a/util.c b/util.c
index 8254677f29732fc6a01a7d9e69e0e70ab760c8ed..a4393887308c24ac4ca637fe6615a4f04f337591 100644 (file)
--- a/util.c
+++ b/util.c
@@ -1151,116 +1151,6 @@ printcall(struct tcb *tcp)
 # define CLONE_VM        0x00000100
 #endif
 
-static int
-change_syscall(struct tcb *tcp, int new)
-{
-#if defined(I386)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_EAX * 4), new) < 0)
-               return -1;
-       return 0;
-#elif defined(X86_64) || defined(X32)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_RAX * 8), new) < 0)
-               return -1;
-       return 0;
-#elif defined(POWERPC)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid,
-                  (char*)(sizeof(unsigned long)*PT_R0), new) < 0)
-               return -1;
-       return 0;
-#elif defined(S390) || defined(S390X)
-       /* s390 linux after 2.4.7 has a hook in entry.S to allow this */
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR2), new) < 0)
-               return -1;
-       return 0;
-#elif defined(M68K)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_ORIG_D0), new) < 0)
-               return -1;
-       return 0;
-#elif defined(SPARC) || defined(SPARC64)
-       struct pt_regs regs;
-       if (ptrace(PTRACE_GETREGS, tcp->pid, (char*)&regs, 0) < 0)
-               return -1;
-       regs.u_regs[U_REG_G1] = new;
-       if (ptrace(PTRACE_SETREGS, tcp->pid, (char*)&regs, 0) < 0)
-               return -1;
-       return 0;
-#elif defined(MIPS)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_V0), new) < 0)
-               return -1;
-       return 0;
-#elif defined(ALPHA)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_A3), new) < 0)
-               return -1;
-       return 0;
-#elif defined(AVR32)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_R8), new) < 0)
-               return -1;
-       return 0;
-#elif defined(BFIN)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_P0), new) < 0)
-               return -1;
-       return 0;
-#elif defined(IA64)
-       if (ia32) {
-               switch (new) {
-               case 2:
-                       break;  /* x86 SYS_fork */
-               case SYS_clone:
-                       new = 120;
-                       break;
-               default:
-                       fprintf(stderr, "%s: unexpected syscall %d\n",
-                               __FUNCTION__, new);
-                       return -1;
-               }
-               if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R1), new) < 0)
-                       return -1;
-       } else if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R15), new) < 0)
-               return -1;
-       return 0;
-#elif defined(HPPA)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GR20), new) < 0)
-               return -1;
-       return 0;
-#elif defined(SH)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*(REG_REG0+3)), new) < 0)
-               return -1;
-       return 0;
-#elif defined(SH64)
-       /* Top half of reg encodes the no. of args n as 0x1n.
-          Assume 0 args as kernel never actually checks... */
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_SYSCALL),
-                               0x100000 | new) < 0)
-               return -1;
-       return 0;
-#elif defined(CRISV10) || defined(CRISV32)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_R9), new) < 0)
-               return -1;
-       return 0;
-#elif defined(ARM)
-       /* Some kernels support this, some (pre-2.6.16 or so) don't.  */
-# ifndef PTRACE_SET_SYSCALL
-#  define PTRACE_SET_SYSCALL 23
-# endif
-       if (ptrace(PTRACE_SET_SYSCALL, tcp->pid, 0, new & 0xffff) != 0)
-               return -1;
-       return 0;
-#elif defined(TILE)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid,
-                  (char*)PTREGS_OFFSET_REG(0),
-                  new) != 0)
-               return -1;
-       return 0;
-#elif defined(MICROBLAZE)
-       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR(0)), new) < 0)
-               return -1;
-       return 0;
-#else
-#warning Do not know how to handle change_syscall for this architecture
-#endif /* architecture */
-       return -1;
-}
-
 #ifdef IA64
 
 typedef unsigned long *arg_setup_state;
@@ -1458,6 +1348,111 @@ set_arg1(struct tcb *tcp, void *cookie, long val)
 # define arg1_index 1
 #endif
 
+static int
+change_syscall(struct tcb *tcp, arg_setup_state *state, int new)
+{
+#if defined(I386)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_EAX * 4), new) < 0)
+               return -1;
+       return 0;
+#elif defined(X86_64) || defined(X32)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_RAX * 8), new) < 0)
+               return -1;
+       return 0;
+#elif defined(POWERPC)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid,
+                  (char*)(sizeof(unsigned long)*PT_R0), new) < 0)
+               return -1;
+       return 0;
+#elif defined(S390) || defined(S390X)
+       /* s390 linux after 2.4.7 has a hook in entry.S to allow this */
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR2), new) < 0)
+               return -1;
+       return 0;
+#elif defined(M68K)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_ORIG_D0), new) < 0)
+               return -1;
+       return 0;
+#elif defined(SPARC) || defined(SPARC64)
+       state->u_regs[U_REG_G1] = new;
+       return 0;
+#elif defined(MIPS)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_V0), new) < 0)
+               return -1;
+       return 0;
+#elif defined(ALPHA)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_A3), new) < 0)
+               return -1;
+       return 0;
+#elif defined(AVR32)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_R8), new) < 0)
+               return -1;
+       return 0;
+#elif defined(BFIN)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_P0), new) < 0)
+               return -1;
+       return 0;
+#elif defined(IA64)
+       if (ia32) {
+               switch (new) {
+               case 2:
+                       break;  /* x86 SYS_fork */
+               case SYS_clone:
+                       new = 120;
+                       break;
+               default:
+                       fprintf(stderr, "%s: unexpected syscall %d\n",
+                               __FUNCTION__, new);
+                       return -1;
+               }
+               if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R1), new) < 0)
+                       return -1;
+       } else if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R15), new) < 0)
+               return -1;
+       return 0;
+#elif defined(HPPA)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GR20), new) < 0)
+               return -1;
+       return 0;
+#elif defined(SH)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*(REG_REG0+3)), new) < 0)
+               return -1;
+       return 0;
+#elif defined(SH64)
+       /* Top half of reg encodes the no. of args n as 0x1n.
+          Assume 0 args as kernel never actually checks... */
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_SYSCALL),
+                               0x100000 | new) < 0)
+               return -1;
+       return 0;
+#elif defined(CRISV10) || defined(CRISV32)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_R9), new) < 0)
+               return -1;
+       return 0;
+#elif defined(ARM)
+       /* Some kernels support this, some (pre-2.6.16 or so) don't.  */
+# ifndef PTRACE_SET_SYSCALL
+#  define PTRACE_SET_SYSCALL 23
+# endif
+       if (ptrace(PTRACE_SET_SYSCALL, tcp->pid, 0, new & 0xffff) != 0)
+               return -1;
+       return 0;
+#elif defined(TILE)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid,
+                  (char*)PTREGS_OFFSET_REG(0),
+                  new) != 0)
+               return -1;
+       return 0;
+#elif defined(MICROBLAZE)
+       if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR(0)), new) < 0)
+               return -1;
+       return 0;
+#else
+#warning Do not know how to handle change_syscall for this architecture
+#endif /* architecture */
+       return -1;
+}
+
 int
 setbpt(struct tcb *tcp)
 {
@@ -1488,7 +1483,8 @@ setbpt(struct tcb *tcp)
                if (arg_setup(tcp, &state) < 0
                    || get_arg0(tcp, &state, &tcp->inst[0]) < 0
                    || get_arg1(tcp, &state, &tcp->inst[1]) < 0
-                   || change_syscall(tcp, clone_scno[current_personality]) < 0
+                   || change_syscall(tcp, &state,
+                                     clone_scno[current_personality]) < 0
                    || set_arg0(tcp, &state, CLONE_PTRACE|SIGCHLD) < 0
                    || set_arg1(tcp, &state, 0) < 0
                    || arg_finish_change(tcp, &state) < 0)
@@ -1531,7 +1527,7 @@ clearbpt(struct tcb *tcp)
 {
        arg_setup_state state;
        if (arg_setup(tcp, &state) < 0
-           || change_syscall(tcp, tcp->scno) < 0
+           || change_syscall(tcp, &state, tcp->scno) < 0
            || restore_arg0(tcp, &state, tcp->inst[0]) < 0
            || restore_arg1(tcp, &state, tcp->inst[1]) < 0
            || arg_finish_change(tcp, &state))