2004-02-23 David Mosberger <davidm@hpl.hp.com>

	Committed by Kevin Buettner <kevinb@redhat.com>.

	* ia64-tdep.h (ia64_write_pc, ia64_linux_write_pc): Declare.
	* ia64-tdep.c (ia64_write_pc): Make it a global function.
	(ia64_gdbarch_init): For Linux targets, use ia64_linux_write_pc()
	instead of ia64_write_pc().
	* ia64-linux-tdep.c (regcache.h): Include.
	(ia64_linux_write_pc): New function.

1 files changed, 18 insertions, 0 deletions

diff --git a/gdb/ia64-linux-tdep.c b/gdb/ia64-linux-tdep.c
index 12f0c18c112..c3fa443a365 100644
--- a/gdb/ia64-linux-tdep.c
+++ b/gdb/ia64-linux-tdep.c
@@ -23,6 +23,7 @@
 #include "ia64-tdep.h"
 #include "arch-utils.h"
 #include "gdbcore.h"
+#include "regcache.h"
 
 /* The sigtramp code is in a non-readable (executable-only) region
    of memory called the ``gate page''.  The addresses in question
@@ -94,3 +95,20 @@ ia64_linux_sigcontext_register_address (CORE_ADDR sp, int regno)
 	return 0;
       }
 }
+
+void
+ia64_linux_write_pc (CORE_ADDR pc, ptid_t ptid)
+{
+  ia64_write_pc (pc, ptid);
+
+  /* We must be careful with modifying the instruction-pointer: if we
+     just interrupt a system call, the kernel would ordinarily try to
+     restart it when we resume the inferior, which typically results
+     in SIGSEGV or SIGILL.  We prevent this by clearing r10, which
+     will tell the kernel that r8 does NOT contain a valid error code
+     and hence it will skip system-call restart.
+
+     The clearing of r10 is safe as long as ia64_write_pc() is only
+     called as part of setting up an inferior call.  */
+  write_register_pid (IA64_GR10_REGNUM, 0, ptid);
+}