Cleanup of the dispatch mechanism. Now syscall returns and the final
request to shutdown valgrind are done with the client request
mechanism too. This is much better than having to check all
call/return addresses.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@57 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/vg_helpers.S b/vg_helpers.S
index 72de134..4d1f8c2 100644
--- a/vg_helpers.S
+++ b/vg_helpers.S
@@ -32,7 +32,46 @@
#include "vg_constants.h"
+/* ------------------ SIMULATED CPU HELPERS ------------------ */
+/* A couple of stubs for returns which we want to catch: signal
+ returns and pthread returns. In the latter case, the thread's
+ return value is in %EAX, so we pass this as the first argument
+ to the request. In both cases we use the user request mechanism.
+ You need to to read the definition of VALGRIND_MAGIC_SEQUENCE
+ in valgrind.h to make sense of this.
+*/
+.global VG_(signalreturn_bogusRA)
+VG_(signalreturn_bogusRA):
+ subl $20, %esp # allocate arg block
+ movl %esp, %edx # %edx == &_zzq_args[0]
+ movl $VG_USERREQ__SIGNAL_RETURNS, 0(%edx) # request
+ movl $0, 4(%edx) # arg1
+ movl $0, 8(%edx) # arg2
+ movl $0, 12(%edx) # arg3
+ movl $0, 16(%edx) # arg4
+ movl %edx, %eax
+ # and now the magic sequence itself:
+ roll $29, %eax
+ roll $3, %eax
+ rorl $27, %eax
+ rorl $5, %eax
+ roll $13, %eax
+ roll $19, %eax
+ # should never get here
+ pushl $signalreturn_bogusRA_panic_msg
+ call VG_(panic)
+
+.data
+signalreturn_bogusRA_panic_msg:
+.ascii "vg_signalreturn_bogusRA: VG_USERREQ__SIGNAL_RETURNS was missed"
+.byte 0
+.text
+
+
+/* ------------------ REAL CPU HELPERS ------------------ */
+/* The rest of this lot run on the real CPU. */
+
/* Various helper routines, for instructions which are just too
darn tedious for the JITter to output code in-line: