sim: Make the syscalls use the SyscallReturn suppression mechanism.

This, among other things, prevents them from needing to toggle global
flags in the syscall desc table to control local behavior.

Jira Issue: https://gem5.atlassian.net/browse/GEM5-187

Change-Id: Idcef23766084f10d5205721b54a6768a850f7eb9
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23167
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>

diff --git a/src/sim/syscall_desc.cc b/src/sim/syscall_desc.cc
index 345bfa114996b871ba51ca82526ac05bb730d802..bf378fe20bd999d42aed31ce0846168dd34535fe 100644 (file)
--- a/src/sim/syscall_desc.cc
+++ b/src/sim/syscall_desc.cc
@@ -81,7 +81,7 @@ SyscallDesc::doSyscall(int callnum, ThreadContext *tc, Fault *fault)
     } else
         DPRINTF_SYSCALL(Base, "%s returns %d\n", _name, retval.encodedValue());
 
-    if (!(_flags & SyscallDesc::SuppressReturnValue) && !retval.needsRetry())
+    if (!retval.suppressed() && !retval.needsRetry())
         process->setSyscallReturn(tc, retval);
 }
 

diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index fc6ed62d150410bfbec3b31ac1131fffea8bf1b1..e467b0bff459568e6824dc07a503721a217dfae3 100644 (file)
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -2131,7 +2131,6 @@ template <class OS>
 SyscallReturn
 execveFunc(SyscallDesc *desc, int callnum, ThreadContext *tc)
 {
-    desc->setFlags(0);
     auto p = tc->getProcessPtr();
 
     int index = 0;
@@ -2215,8 +2214,7 @@ execveFunc(SyscallDesc *desc, int callnum, ThreadContext *tc)
     TheISA::PCState pcState = tc->pcState();
     tc->setNPC(pcState.instAddr());
 
-    desc->setFlags(SyscallDesc::SuppressReturnValue);
-    return 0;
+    return SyscallReturn();
 }
 
 /// Target getrusage() function.