Reduce code redundancy in syscall_enter()

* syscall.c [LINUX] (syscall_enter): Move tcp->u_nargs initialization
from arch-specific ifdefs to common code.  Always cache tcp->u_nargs in
a local variable and use it in for() loops.
[IA64, AVR32] Rewrite tcp->u_arg[] initialization using a loop.

diff --git a/syscall.c b/syscall.c
index 2af908573a8b541c11cc1b4b214c2203570fc361..a3b5727b35314bffb6f9c6f625ed3bc5662650c4 100644 (file)
--- a/syscall.c
+++ b/syscall.c
@@ -2003,32 +2003,24 @@ static int
 syscall_enter(struct tcb *tcp)
 {
 #ifdef LINUX
-# if defined(S390) || defined(S390X)
-       int i;
+       int i, nargs;
+
        if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               tcp->u_nargs = sysent[tcp->scno].nargs;
+               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
        else
-               tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < tcp->u_nargs; i++) {
+               nargs = tcp->u_nargs = MAX_ARGS;
+
+# if defined(S390) || defined(S390X)
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, i==0 ? PT_ORIGGPR2 : PT_GPR2 + i*sizeof(long), &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(ALPHA)
-       int i;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < tcp->u_nargs; i++) {
-               /* WTA: if scno is out-of-bounds this will bomb. Add range-check
-                * for scno somewhere above here!
-                */
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, REG_A0+i, &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(IA64)
        if (!ia32) {
-               unsigned long *out0, cfm, sof, sol, i;
+               unsigned long *out0, cfm, sof, sol;
                long rbs_end;
                /* be backwards compatible with kernel < 2.4.4... */
 #              ifndef PT_RBS_END
@@ -2044,92 +2036,60 @@ syscall_enter(struct tcb *tcp)
                sol = (cfm >> 7) & 0x7f;
                out0 = ia64_rse_skip_regs((unsigned long *) rbs_end, -sof + sol);
 
-               if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-                       tcp->u_nargs = sysent[tcp->scno].nargs;
-               else
-                       tcp->u_nargs = MAX_ARGS;
-               for (i = 0; i < tcp->u_nargs; ++i) {
+               for (i = 0; i < nargs; ++i) {
                        if (umoven(tcp, (unsigned long) ia64_rse_skip_regs(out0, i),
                                   sizeof(long), (char *) &tcp->u_arg[i]) < 0)
                                return -1;
                }
        } else {
-               int i;
-
-               if (/* EBX = out0 */
-                   upeek(tcp, PT_R11, (long *) &tcp->u_arg[0]) < 0
-                   /* ECX = out1 */
-                   || upeek(tcp, PT_R9,  (long *) &tcp->u_arg[1]) < 0
-                   /* EDX = out2 */
-                   || upeek(tcp, PT_R10, (long *) &tcp->u_arg[2]) < 0
-                   /* ESI = out3 */
-                   || upeek(tcp, PT_R14, (long *) &tcp->u_arg[3]) < 0
-                   /* EDI = out4 */
-                   || upeek(tcp, PT_R15, (long *) &tcp->u_arg[4]) < 0
-                   /* EBP = out5 */
-                   || upeek(tcp, PT_R13, (long *) &tcp->u_arg[5]) < 0)
-                       return -1;
-
-               for (i = 0; i < 6; ++i)
+               static const int argreg[MAX_ARGS] = { PT_R11 /* EBX = out0 */,
+                                                     PT_R9  /* ECX = out1 */,
+                                                     PT_R10 /* EDX = out2 */,
+                                                     PT_R14 /* ESI = out3 */,
+                                                     PT_R15 /* EDI = out4 */,
+                                                     PT_R13 /* EBP = out5 */};
+
+               for (i = 0; i < nargs; ++i) {
+                       if (upeek(tcp, argreg[i], &tcp->u_arg[i]) < 0)
+                               return -1;
                        /* truncate away IVE sign-extension */
                        tcp->u_arg[i] &= 0xffffffff;
-
-               if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-                       tcp->u_nargs = sysent[tcp->scno].nargs;
-               else
-                       tcp->u_nargs = 5;
+               }
        }
 # elif defined(LINUX_MIPSN32) || defined(LINUX_MIPSN64)
        /* N32 and N64 both use up to six registers.  */
        unsigned long long regs[38];
-       int i, nargs;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = MAX_ARGS;
 
        if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, (long) &regs) < 0)
                return -1;
 
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i) {
                tcp->u_arg[i] = regs[REG_A0 + i];
 #  if defined(LINUX_MIPSN32)
                tcp->ext_arg[i] = regs[REG_A0 + i];
 #  endif
        }
 # elif defined(MIPS)
-       long sp;
-       int i, nargs;
-
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = MAX_ARGS;
        if (nargs > 4) {
+               long sp;
+
                if (upeek(tcp, REG_SP, &sp) < 0)
                        return -1;
-               for (i = 0; i < 4; i++) {
+               for (i = 0; i < 4; ++i)
                        if (upeek(tcp, REG_A0 + i, &tcp->u_arg[i]) < 0)
                                return -1;
-               }
-               umoven(tcp, sp+16, (nargs-4) * sizeof(tcp->u_arg[0]),
+               umoven(tcp, sp + 16, (nargs - 4) * sizeof(tcp->u_arg[0]),
                       (char *)(tcp->u_arg + 4));
        } else {
-               for (i = 0; i < nargs; i++) {
+               for (i = 0; i < nargs; ++i)
                        if (upeek(tcp, REG_A0 + i, &tcp->u_arg[i]) < 0)
                                return -1;
-               }
        }
 # elif defined(POWERPC)
 #  ifndef PT_ORIG_R3
 #   define PT_ORIG_R3 34
 #  endif
-       int i, nargs;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i) {
                if (upeek(tcp, (i==0) ?
                        (sizeof(unsigned long) * PT_ORIG_R3) :
                        ((i+PT_R3) * sizeof(unsigned long)),
@@ -2137,151 +2097,81 @@ syscall_enter(struct tcb *tcp)
                        return -1;
        }
 # elif defined(SPARC) || defined(SPARC64)
-       int i;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < tcp->u_nargs; i++)
+       for (i = 0; i < nargs; ++i)
                tcp->u_arg[i] = regs.u_regs[U_REG_O0 + i];
 # elif defined(HPPA)
-       int i, nargs;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, PT_GR26-4*i, &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(ARM)
-       int i;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < tcp->u_nargs; i++)
+       for (i = 0; i < nargs; ++i)
                tcp->u_arg[i] = regs.uregs[i];
 # elif defined(AVR32)
-       tcp->u_nargs = sysent[tcp->scno].nargs;
-       tcp->u_arg[0] = regs.r12;
-       tcp->u_arg[1] = regs.r11;
-       tcp->u_arg[2] = regs.r10;
-       tcp->u_arg[3] = regs.r9;
-       tcp->u_arg[4] = regs.r5;
-       tcp->u_arg[5] = regs.r3;
+       static const unsigned long *argregp[MAX_ARGS] = { &regs.r12,
+                                                         &regs.r11,
+                                                         &regs.r10,
+                                                         &regs.r9,
+                                                         &regs.r5,
+                                                         &regs.r3 };
+       for (i = 0; i < nargs; ++i)
+               tcp->u_arg[i] = *argregp[i];
 # elif defined(BFIN)
-       int i, nargs;
-       static const int argreg[] = { PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5 };
-
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = ARRAY_SIZE(argreg);
+       static const int argreg[MAX_ARGS] = { PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5 };
 
        for (i = 0; i < nargs; ++i)
                if (upeek(tcp, argreg[i], &tcp->u_arg[i]) < 0)
                        return -1;
 # elif defined(SH)
-       int i, nargs;
-       static const int syscall_regs[] = {
-               4 * (REG_REG0+4), 4 * (REG_REG0+5), 4 * (REG_REG0+6), 4 * (REG_REG0+7),
-               4 * (REG_REG0  ), 4 * (REG_REG0+1), 4 * (REG_REG0+2)
+       static const int syscall_regs[MAX_ARGS] = {
+               4 * (REG_REG0+4), 4 * (REG_REG0+5), 4 * (REG_REG0+6),
+               4 * (REG_REG0+7), 4 * (REG_REG0  ), 4 * (REG_REG0+1)
        };
 
-       nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, syscall_regs[i], &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(SH64)
        int i;
        /* Registers used by SH5 Linux system calls for parameters */
-       static const int syscall_regs[] = { 2, 3, 4, 5, 6, 7 };
+       static const int syscall_regs[MAX_ARGS] = { 2, 3, 4, 5, 6, 7 };
 
-       /*
-        * TODO: should also check that the number of arguments encoded
-        *       in the trap number matches the number strace expects.
-        */
-       /*
-       assert(sysent[tcp->scno].nargs < ARRAY_SIZE(syscall_regs));
-        */
-
-       nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, REG_GENERAL(syscall_regs[i]), &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(X86_64)
-       int i, nargs;
        static const int argreg[SUPPORTED_PERSONALITIES][MAX_ARGS] = {
                { 8 * RDI, 8 * RSI, 8 * RDX, 8 * R10, 8 * R8 , 8 * R9  }, /* x86-64 ABI */
                { 8 * RBX, 8 * RCX, 8 * RDX, 8 * RSI, 8 * RDI, 8 * RBP }  /* i386 ABI */
        };
 
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, argreg[current_personality][i], &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(MICROBLAZE)
-       int i, nargs;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = 0;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, (5 + i) * 4, &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(CRISV10) || defined(CRISV32)
-       int i, nargs;
-       static const int crisregs[] = {
+       static const int crisregs[MAX_ARGS] = {
                4*PT_ORIG_R10, 4*PT_R11, 4*PT_R12,
                4*PT_R13     , 4*PT_MOF, 4*PT_SRP
        };
 
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = 0;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, crisregs[i], &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(TILE)
-       int i, nargs;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < nargs; ++i) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, PTREGS_OFFSET_REG(i), &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # elif defined(M68K)
-       int i, nargs;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, (i < 5 ? i : i + 2)*4, &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # else /* Other architecture (like i386) (32bits specific) */
-       int i, nargs;
-       if (tcp->scno >= 0 && tcp->scno < nsyscalls)
-               nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-       else
-               nargs = tcp->u_nargs = MAX_ARGS;
-       for (i = 0; i < nargs; i++) {
+       for (i = 0; i < nargs; ++i)
                if (upeek(tcp, i*4, &tcp->u_arg[i]) < 0)
                        return -1;
-       }
 # endif
 #endif /* LINUX */
 #ifdef SUNOS4