2008-05-27 Roland McGrath <roland@redhat.com>

	* syscall.c [LINUX] (is_negated_errno): New function.
	(get_error) [LINUX]: Use it for all such cases.
	Fixes RH#447587.

diff --git a/syscall.c b/syscall.c
index a2d26d39b7aa2aad3c6b53e7d32998ba87a07d21..428b86860c1a86708305f2b441e0f6e893d309ab 100644 (file)
--- a/syscall.c
+++ b/syscall.c
@@ -1473,6 +1473,23 @@ struct tcb *tcp;
        return 1;
 }
 
+#ifdef LINUX
+/*
+ * Check the syscall return value register value for whether it is
+ * a negated errno code indicating an error, or a success return value.
+ */
+static inline int
+is_negated_errno(unsigned long int val)
+{
+       unsigned long int max = -(long int) nerrnos;
+       if (personality_wordsize[current_personality] < sizeof(val)) {
+               val = (unsigned int) val;
+               max = (unsigned int) max;
+       }
+       return val > max;
+}
+#endif
+
 static int
 get_error(tcp)
 struct tcb *tcp;
@@ -1480,57 +1497,57 @@ struct tcb *tcp;
        int u_error = 0;
 #ifdef LINUX
 #if defined(S390) || defined(S390X)
-               if (gpr2 && (unsigned) -gpr2 < nerrnos) {
-                       tcp->u_rval = -1;
-                       u_error = -gpr2;
-               }
-               else {
-                       tcp->u_rval = gpr2;
-                       u_error = 0;
-               }
+       if (is_negated_errno(gpr2)) {
+               tcp->u_rval = -1;
+               u_error = -gpr2;
+       }
+       else {
+               tcp->u_rval = gpr2;
+               u_error = 0;
+       }
 #else /* !S390 && !S390X */
 #ifdef I386
-               if (eax < 0 && -eax < nerrnos) {
-                       tcp->u_rval = -1;
-                       u_error = -eax;
-               }
-               else {
-                       tcp->u_rval = eax;
-                       u_error = 0;
-               }
+       if (is_negated_errno(eax)) {
+               tcp->u_rval = -1;
+               u_error = -eax;
+       }
+       else {
+               tcp->u_rval = eax;
+               u_error = 0;
+       }
 #else /* !I386 */
 #ifdef X86_64
-               if (rax < 0 && -rax < nerrnos) {
+       if (is_negated_errno(rax)) {
+               tcp->u_rval = -1;
+               u_error = -rax;
+       }
+       else {
+               tcp->u_rval = rax;
+               u_error = 0;
+       }
+#else
+#ifdef IA64
+       if (ia32) {
+               int err;
+
+               err = (int)r8;
+               if (is_negated_errno(err)) {
                        tcp->u_rval = -1;
-                       u_error = -rax;
+                       u_error = -err;
                }
                else {
-                       tcp->u_rval = rax;
+                       tcp->u_rval = err;
                        u_error = 0;
                }
-#else
-#ifdef IA64
-               if (ia32) {
-                       int err;
-
-                       err = (int)r8;
-                       if (err < 0 && -err < nerrnos) {
-                               tcp->u_rval = -1;
-                               u_error = -err;
-                       }
-                       else {
-                               tcp->u_rval = err;
-                               u_error = 0;
-                       }
+       } else {
+               if (r10) {
+                       tcp->u_rval = -1;
+                       u_error = r8;
                } else {
-                       if (r10) {
-                               tcp->u_rval = -1;
-                               u_error = r8;
-                       } else {
-                               tcp->u_rval = r8;
-                               u_error = 0;
-                       }
+                       tcp->u_rval = r8;
+                       u_error = 0;
                }
+       }
 #else /* !IA64 */
 #ifdef MIPS
                if (a3) {
@@ -1542,7 +1559,7 @@ struct tcb *tcp;
                }
 #else
 #ifdef POWERPC
-               if (result && (unsigned long) -result < nerrnos) {
+               if (is_negated_errno(result)) {
                        tcp->u_rval = -1;
                        u_error = -result;
                }
@@ -1552,7 +1569,7 @@ struct tcb *tcp;
                }
 #else /* !POWERPC */
 #ifdef M68K
-               if (d0 && (unsigned) -d0 < nerrnos) {
+               if (is_negated_errno(d0)) {
                        tcp->u_rval = -1;
                        u_error = -d0;
                }
@@ -1562,7 +1579,7 @@ struct tcb *tcp;
                }
 #else /* !M68K */
 #ifdef ARM
-               if (regs.ARM_r0 && (unsigned) -regs.ARM_r0 < nerrnos) {
+               if (is_negated_errno(regs.ARM_r0)) {
                        tcp->u_rval = -1;
                        u_error = -regs.ARM_r0;
                }
@@ -1602,7 +1619,7 @@ struct tcb *tcp;
                }
 #else /* !SPARC64 */
 #ifdef HPPA
-               if (r28 && (unsigned) -r28 < nerrnos) {
+               if (is_negated_errno(r28)) {
                        tcp->u_rval = -1;
                        u_error = -r28;
                }
@@ -1612,19 +1629,19 @@ struct tcb *tcp;
                }
 #else
 #ifdef SH
-               /* interpret R0 as return value or error number */
-               if (r0 && (unsigned) -r0 < nerrnos) {
-                       tcp->u_rval = -1;
-                       u_error = -r0;
-               }
-               else {
-                       tcp->u_rval = r0;
-                       u_error = 0;
-               }
+               /* interpret R0 as return value or error number */
+               if (is_negated_errno(r0)) {
+                       tcp->u_rval = -1;
+                       u_error = -r0;
+               }
+               else {
+                       tcp->u_rval = r0;
+                       u_error = 0;
+               }
 #else
 #ifdef SH64
                 /* interpret result as return value or error number */
-                if (r9 && (unsigned) -r9 < nerrnos) {
+                if (is_negated_errno(r9)) {
                        tcp->u_rval = -1;
                        u_error = -r9;
                 }
@@ -2007,7 +2024,7 @@ struct tcb *tcp;
 
                if (tcp->scno >= 0 && tcp->scno < nsyscalls && sysent[tcp->scno].nargs != -1)
                        nargs = tcp->u_nargs = sysent[tcp->scno].nargs;
-               else 
+               else
                        nargs = tcp->u_nargs = MAX_ARGS;
 
                if (ptrace (PTRACE_GETREGS, pid, NULL, (long) &regs) < 0)