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Simplify memory manager code

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Justine Tunney 2024-12-28 17:08:18 -08:00
parent 379cd77078
commit aca4214ff6
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GPG key ID: BE714B4575D6E328
11 changed files with 442 additions and 325 deletions
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34
libc/intrin/sig.c
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@ -588,6 +588,22 @@ textwindows static void __sig_unmaskable(struct SignalFrame *sf) {
DescribeBacktrace(
(struct StackFrame *)sf->ctx.uc_mcontext.gregs[REG_RBP]));
// kills process if the user did not specify a handler for this signal
// we also don't allow unmaskable signals to be ignored by the program
if (sf->rva == (intptr_t)SIG_DFL || //
sf->rva == (intptr_t)SIG_IGN)
__sig_death(sf->si.si_signo, "uncaught ");
// we kill the process if this thread's signal mask blocks this signal
// then we block some extra signals while executing the signal handler
struct CosmoTib *tib = __get_tls();
sigset_t blocksigs = __sighandmask[sf->si.si_signo];
if (!(sf->flags & SA_NODEFER))
blocksigs |= 1ull << (sf->si.si_signo - 1);
sf->ctx.uc_sigmask = atomic_fetch_or(&tib->tib_sigmask, blocksigs);
if (sf->ctx.uc_sigmask & (1ull << (sf->si.si_signo - 1)))
__sig_death(sf->si.si_signo, "masked ");
// this will restore the guard page if the user is using a sigaltstack
if (sf->si.si_errno == kNtStatusGuardPageViolation)
__sig_reguard(sf->si.si_addr);
@ -620,22 +636,6 @@ __msabi HAIRY static unsigned __sig_crash(struct NtExceptionPointers *ep) {
if (flags & SA_RESETHAND)
__sighandrvas[sig] = (int32_t)(intptr_t)SIG_DFL;
// kills process if the user did not specify a handler for this signal
// we also don't allow unmaskable signals to be ignored by the program
if (rva == (intptr_t)SIG_DFL || //
rva == (intptr_t)SIG_IGN)
__sig_death(sig, "uncaught ");
// we kill the process if this thread's signal mask blocks this signal
// then we block some extra signals while executing the signal handler
struct CosmoTib *tib = __get_tls();
sigset_t blocksigs = __sighandmask[sig];
if (!(flags & SA_NODEFER))
blocksigs |= 1ull << (sig - 1);
sigset_t oldsigmask = atomic_fetch_or(&tib->tib_sigmask, blocksigs);
if (oldsigmask & (1ull << (sig - 1)))
__sig_death(sig, "masked ");
// we don't know if it is safe for signal handlers to longjmp() out of
// win32 vectored exception handlers so let's copy the machine context
// and tell win32 to restore control to __sig_unmaskable() which shall
@ -643,6 +643,7 @@ __msabi HAIRY static unsigned __sig_crash(struct NtExceptionPointers *ep) {
// was caused by stack overflow, then we're literally executing inside
// the guard page so this code can't use more than 4096 bytes of stack
uintptr_t sp;
struct CosmoTib *tib = __get_tls();
if (__sig_should_use_altstack(flags, tib)) {
sp = (uintptr_t)tib->tib_sigstack_addr + tib->tib_sigstack_size;
} else {
@ -654,7 +655,6 @@ __msabi HAIRY static unsigned __sig_crash(struct NtExceptionPointers *ep) {
struct SignalFrame *sf = (struct SignalFrame *)sp;
__repstosb(sf, 0, sizeof(*sf));
__sig_translate(&sf->ctx, ep->ContextRecord);
sf->ctx.uc_sigmask = oldsigmask;
sf->rva = rva;
sf->flags = flags;
sf->si.si_code = sic;