test: add more cases for sigTest

src/sigTest.c

@@ -473,3 +473,156 @@ KTEST(sigConsumePendingDefaultDispositionReturnsTerminate)
     KT_EQU(t, regs.rax, before.rax);
     KT_EQU(t, thread->sigHandlerDepth, 0u);
 
+    KT_TRUE(t, threadDiscard(id));
+}
+
+KTEST(sigConsumePendingSigTstpDefaultDispositionReturnsStopOutcome)
+{
+    uint32 id = threadCreate("sigConsumeTstp", noopThreadEntry);
+    KT_NE(t, id, threadInvalidId);
+    Thread* thread = threadAt(id);
+    Registers regs = makeUserRegs();
+    Registers before = regs;
+    int signum = -1;
+
+    /* SIGTSTP's real-world default disposition is Stop, not Terminate --
+       the catchable half of job control (see sigDefaultIsStop, signal.c).
+       sigStop itself never reaches here at all (sigRaise bypasses this
+       whole scan for it, see sigRaiseSigStopDelegatesToThreadStopAndBypassesPending
+       above), so this is the ONLY way sigOutcomeStop is ever produced. */
+    sigRaise(id, sigTstp);
+    KT_EQ(t, sigConsumePending(thread, &regs, &signum), sigOutcomeStop);
+    KT_EQ(t, signum, sigTstp);
+    KT_FALSE(t, thread->sigPending & (1ull << sigTstp));
+
+    /* Reported, not carried out, here -- isr.c's deliverPendingSignals is
+       the one that actually calls threadStop, the same contract
+       sigOutcomeTerminate already has with threadExit. */
+    KT_EQU(t, regs.rip, before.rip);
+    KT_EQU(t, regs.rax, before.rax);
+    KT_EQU(t, thread->sigHandlerDepth, 0u);
+    KT_EQ(t, thread->state, threadRunnable);
+
+    KT_TRUE(t, threadDiscard(id));
+}
+
+KTEST(sigConsumePendingSigTstpWithHandlerRunsHandlerInsteadOfStopping)
+{
+    uint32 id = threadCreate("sigConsumeTstpCaught", noopThreadEntry);
+    KT_NE(t, id, threadInvalidId);
+    Thread* thread = threadAt(id);
+    Registers regs = makeUserRegs();
+    int signum = -1;
+
+    /* Unlike SIGSTOP, SIGTSTP is fully catchable: an installed handler
+       overrides the default Stop disposition, exactly like any other
+       catchable signal overriding a default Terminate. */
+    uint64 handlerAddr = 0x4000A000ull;
+    sigSetHandler(thread, sigTstp, handlerAddr, 0, 0);
+    sigRaise(id, sigTstp);
+
+    KT_EQ(t, sigConsumePending(thread, &regs, &signum), sigOutcomeHandler);
+    KT_EQ(t, signum, sigTstp);
+    KT_EQU(t, regs.rax, handlerAddr);
+    KT_EQU(t, regs.rip, sigTrampolineVirtualAddr);
+    KT_EQU(t, thread->sigHandlerDepth, 1u);
+
+    KT_TRUE(t, threadDiscard(id));
+}
+
+KTEST(sigConsumePendingSaMaskDefersDifferentSignalUntilHandlerReturns)
+{
+    uint32 id = threadCreate("sigSaMaskTarget", noopThreadEntry);
+    KT_NE(t, id, threadInvalidId);
+    Thread* thread = threadAt(id);
+    Registers regs = makeUserRegs();
+    int signum = -1;
+
+    /* sigUsr1's sa_mask explicitly includes sigHup -- unlike the nesting
+       test below (mask 0), THIS is what should keep sigHup from
+       interrupting sigUsr1's handler at all. */
+    uint64 usr1Handler = 0x40009000ull;
+    uint64 hupHandler = 0x4000C000ull;
+    sigSetHandler(thread, sigUsr1, usr1Handler, (1ull << sigHup), 0);
+    sigSetHandler(thread, sigHup, hupHandler, 0, 0);
+
+    sigRaise(id, sigUsr1);
+    KT_EQ(t, sigConsumePending(thread, &regs, &signum), sigOutcomeHandler);
+    KT_EQ(t, signum, sigUsr1);
+    KT_TRUE(t, thread->sigBlocked & (1ull << sigHup));
+
+    /* sigHup arrives while sigUsr1's handler is active -- masked by its
+       sa_mask, so it must stay pending, NOT nest, unlike an unmasked
+       signal would (see the nesting test below). */
+    sigRaise(id, sigHup);
+    int deferredSignum = -1;
+    KT_EQ(t, sigConsumePending(thread, &regs, &deferredSignum), sigOutcomeNone);
+    KT_EQ(t, deferredSignum, -1);
+    KT_TRUE(t, thread->sigPending & (1ull << sigHup));
+    KT_EQU(t, thread->sigHandlerDepth, 1u);
+
+    /* Once sigUsr1's handler returns, its sa_mask's grip on sigHup ends
+       with it (sigBlocked restored to what it was before) -- the deferred
+       signal is finally deliverable, as its own TOP-LEVEL handler, not a
+       nested one. */
+    KT_TRUE(t, sigOnSigReturn(thread, &regs));
+    KT_FALSE(t, thread->sigBlocked & (1ull << sigHup));
+
+    int finalSignum = -1;
+    KT_EQ(t, sigConsumePending(thread, &regs, &finalSignum), sigOutcomeHandler);
+    KT_EQ(t, finalSignum, sigHup);
+    KT_EQU(t, regs.rax, hupHandler);
+    KT_EQU(t, thread->sigHandlerDepth, 1u);
+
+    KT_TRUE(t, threadDiscard(id));
+}
+
+/* Default (sigFlagNoDefer NOT set) half of the contrast: a signal raised
+   again against ITSELF while its own handler is still active must stay
+   merely pending, not nest -- sigConsumePendingCustomHandlerRewritesTrapframeAndPushesContext
+   above already asserts sigUsr1's own bit lands in sigBlocked once its
+   handler starts; this test is the direct behavioral consequence of that
+   bit actually being there, driven the same way
+   sigConsumePendingSaMaskDefersDifferentSignalUntilHandlerReturns drives
+   sa_mask's deferral. */
+KTEST(sigConsumePendingDefersSameSignalRaisedAgainWhileItsOwnHandlerIsActive)
+{
+    uint32 id = threadCreate("sigNoDeferOffTarget", noopThreadEntry);
+    KT_NE(t, id, threadInvalidId);
+    Thread* thread = threadAt(id);
+    Registers regs = makeUserRegs();
+    int signum = -1;
+
+    uint64 handlerAddr = 0x40009000ull;
+    sigSetHandler(thread, sigUsr1, handlerAddr, 0, 0);
+    sigRaise(id, sigUsr1);
+
+    KT_EQ(t, sigConsumePending(thread, &regs, &signum), sigOutcomeHandler);
+    KT_EQ(t, signum, sigUsr1);
+    KT_TRUE(t, thread->sigBlocked & (1ull << sigUsr1));
+    KT_EQU(t, thread->sigHandlerDepth, 1u);
+
+    /* Same signum, raised again while its own handler is still active --
+       self-blocked (no sigFlagNoDefer), so this must stay pending, not
+       enter a second, nested instance of the same handler. */
+    sigRaise(id, sigUsr1);
+    int deferredSignum = -1;
+    KT_EQ(t, sigConsumePending(thread, &regs, &deferredSignum), sigOutcomeNone);
+    KT_EQ(t, deferredSignum, -1);
+    KT_TRUE(t, thread->sigPending & (1ull << sigUsr1));
+    KT_EQU(t, thread->sigHandlerDepth, 1u);
+
+    /* Once the (only) active handler returns, its self-block lifts and the
+       deferred re-raise is finally deliverable -- as a fresh TOP-LEVEL
+       invocation (depth back to 1, not 2), never having nested at all. */
+    KT_TRUE(t, sigOnSigReturn(thread, &regs));
+    KT_FALSE(t, thread->sigBlocked & (1ull << sigUsr1));
+
+    int finalSignum = -1;
+    KT_EQ(t, sigConsumePending(thread, &regs, &finalSignum), sigOutcomeHandler);
+    KT_EQ(t, finalSignum, sigUsr1);
+    KT_EQU(t, thread->sigHandlerDepth, 1u);
+
+    KT_TRUE(t, threadDiscard(id));
+}
+