Kernel/riscv64: Implement the signal trampoline

This commit is contained in:
Sönke Holz 2024-03-09 14:25:51 +01:00 committed by Andrew Kaster
parent 66f8d0f031
commit 496a7541a2

View file

@ -458,13 +458,31 @@ void signal_trampoline_dummy()
"asm_signal_trampoline_end: \n" ::[sigreturn_syscall_number] "i"(Syscall::SC_sigreturn),
[offset_to_first_register_slot] "i"(offset_to_first_register_slot));
#elif ARCH(RISCV64)
constexpr static auto offset_to_a0_slot = align_up_to(sizeof(__ucontext) + sizeof(siginfo) + sizeof(FPUState) + 3 * sizeof(FlatPtr), 16);
constexpr static auto offset_to_a0_slot = sizeof(__ucontext) + sizeof(siginfo) + sizeof(FPUState) + 4 * sizeof(FlatPtr);
asm(
".global asm_signal_trampoline\n"
"asm_signal_trampoline:\n"
// stack state: 0, ucontext, signal_info (alignment = 16), fpu_state (alignment = 16), ucontext*, siginfo*, signal, handler
// FIXME: Implement this
// Load the handler address into t0.
"ld t0, 0(sp)\n"
// Store a0 (return value from a syscall) into the register slot, such that we can return the correct value in sys$sigreturn.
"sd a0, %[offset_to_first_register_slot](sp)\n"
// Load the signal number into the first argument.
"ld a0, 8(sp)\n"
// Load a pointer to the signal_info structure into the second argument.
"ld a1, 16(sp)\n"
// Load a pointer to the ucontext into the third argument.
"ld a2, 24(sp)\n"
// Pop the values off the stack.
"addi sp, sp, 32\n"
// Call the signal handler.
"jalr t0\n"
// Call sys$sigreturn.
"li a7, %[sigreturn_syscall_number]\n"
"ecall\n"
// We should never return, so trap if we do return.
"unimp\n"
"\n"