From 98a2a566d91e1f6c3431b0e180c8208a6d0e9e79 Mon Sep 17 00:00:00 2001
From: 4lDO2 <4lDO2@protonmail.com>
Date: Sun, 23 Jun 2024 23:30:34 +0200
Subject: [PATCH] Almost succeed at repeatedly accepting signals.
---
redox-rt/src/arch/x86_64.rs | 26 +++++++++++++++-----------
redox-rt/src/proc.rs | 14 ++++++++------
redox-rt/src/signal.rs | 19 ++++++++++++-------
3 files changed, 35 insertions(+), 24 deletions(-)
diff --git a/redox-rt/src/arch/x86_64.rs b/redox-rt/src/arch/x86_64.rs
index 54a57ae1..7349809f 100644
--- a/redox-rt/src/arch/x86_64.rs
+++ b/redox-rt/src/arch/x86_64.rs
@@ -150,13 +150,13 @@ asmfunction!(__relibc_internal_sigentry: ["
and eax, ecx
and eax, {SIGW1_PENDING_MASK}
bsf eax, eax
- jnz 4f
+ jnz 7f
add eax, 32
2:
// By now we have selected a signal, stored in eax (6-bit). We now need to choose whether or
// not to switch to the alternate signal stack. If SA_ONSTACK is clear for this signal, then
// skip the sigaltstack logic.
- bt fs:[{tcb_sa_off} + {sa_onstack}], edx
+ bt fs:[{tcb_sa_off} + {sa_onstack}], eax
jc 3f
// Otherwise, the altstack is already active. The sigaltstack being disabled, is equivalent
@@ -180,10 +180,10 @@ asmfunction!(__relibc_internal_sigentry: ["
4:
// Now that we have a stack, we can finally start initializing the signal stack!
- push 0 // SS
+ push 0x23 // SS
push fs:[{tcb_sc_off} + {sc_saved_rsp}]
push fs:[{tcb_sc_off} + {sc_saved_rflags}]
- push 0 // CS
+ push 0x2b // CS
push fs:[{tcb_sc_off} + {sc_saved_rip}]
push rdi
@@ -202,7 +202,7 @@ asmfunction!(__relibc_internal_sigentry: ["
push r14
push r15
- push rdx // selected signal
+ push rax // selected signal
sub rsp, 4096 + 24
@@ -214,7 +214,7 @@ asmfunction!(__relibc_internal_sigentry: ["
// TODO: self-modifying?
cmp byte ptr [rip + {supports_xsave}], 0
- je 3f
+ je 6f
mov eax, 0xffffffff
mov edx, eax
@@ -227,8 +227,8 @@ asmfunction!(__relibc_internal_sigentry: ["
mov edx, eax
xrstor [rsp]
- add rsp, 4096 + 24
-2:
+5:
+ add rsp, 4096 + 32
pop r15
pop r14
pop r13
@@ -245,20 +245,24 @@ asmfunction!(__relibc_internal_sigentry: ["
pop rsi
pop rdi
+ iretq
+ /*
pop qword ptr fs:[{tcb_sa_off} + {sa_tmp}]
add rsp, 8
popfq
pop rsp
jmp qword ptr fs:[{tcb_sa_off} + {sa_tmp}]
-3:
+ */
+6:
fxsave64 [rsp]
mov rdi, rsp
call {inner}
fxrstor64 [rsp]
- jmp 2b
-4:
+ jmp 5b
+7:
+ ud2
// Spurious signal
"] <= [
inner = sym inner_c,
diff --git a/redox-rt/src/proc.rs b/redox-rt/src/proc.rs
index 218bf18d..e4564bb7 100644
--- a/redox-rt/src/proc.rs
+++ b/redox-rt/src/proc.rs
@@ -795,6 +795,14 @@ pub fn fork_inner(initial_rsp: *mut usize) -> Result<usize> {
}
}
+ let buf = create_set_addr_space_buf(
+ *new_addr_space_fd,
+ __relibc_internal_fork_ret as usize,
+ initial_rsp as usize,
+ );
+ let _ = syscall::write(*new_addr_space_sel_fd, &buf)?;
+ }
+ {
// Reuse the same sigaltstack and signal entry (all memory will be re-mapped CoW later).
//
// Do this after the address space is cloned, since the kernel will get a shared
@@ -804,12 +812,6 @@ pub fn fork_inner(initial_rsp: *mut usize) -> Result<usize> {
let _ = syscall::write(*new_sighandler_fd, &crate::signal::current_setsighandler_struct())?;
}
- let buf = create_set_addr_space_buf(
- *new_addr_space_fd,
- __relibc_internal_fork_ret as usize,
- initial_rsp as usize,
- );
- let _ = syscall::write(*new_addr_space_sel_fd, &buf)?;
}
copy_env_regs(*cur_pid_fd, *new_pid_fd)?;
}
diff --git a/redox-rt/src/signal.rs b/redox-rt/src/signal.rs
index d90c2c89..2ec1e76c 100644
--- a/redox-rt/src/signal.rs
+++ b/redox-rt/src/signal.rs
@@ -2,7 +2,7 @@ use core::cell::{Cell, UnsafeCell};
use core::ffi::c_int;
use core::sync::atomic::{AtomicU64, Ordering};
-use syscall::{Error, IntRegisters, Result, SetSighandlerData, SigProcControl, Sigcontrol, EINVAL, SIGCHLD, SIGCONT, SIGKILL, SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGURG, SIGW0_NOCLDSTOP_BIT, SIGW0_TSTP_IS_STOP_BIT, SIGW0_TTIN_IS_STOP_BIT, SIGW0_TTOU_IS_STOP_BIT, SIGWINCH};
+use syscall::{Error, IntRegisters, Result, SetSighandlerData, SigProcControl, Sigcontrol, SigcontrolFlags, EINVAL, SIGCHLD, SIGCONT, SIGKILL, SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGURG, SIGW0_NOCLDSTOP_BIT, SIGW0_TSTP_IS_STOP_BIT, SIGW0_TTIN_IS_STOP_BIT, SIGW0_TTOU_IS_STOP_BIT, SIGWINCH};
use crate::{arch::*, Tcb};
use crate::sync::Mutex;
@@ -28,25 +28,30 @@ pub fn sighandler_function() -> usize {
#[repr(C)]
pub struct SigStack {
- sa_handler: usize,
- sig_num: usize,
-
#[cfg(target_arch = "x86_64")]
fx: [u8; 4096],
#[cfg(target_arch = "x86")]
fx: [u8; 512],
- _pad: [usize; 4], // pad to 192 = 3 * 64 bytes
+ _pad: [usize; 3], // pad to 192 = 3 * 64 = 168 + 24 bytes
+ sig_num: usize,
regs: IntRegisters, // 160 bytes currently
}
#[inline(always)]
unsafe fn inner(stack: &mut SigStack) {
+ // TODO: Set procmask based on SA_NODEFER, SA_RESETHAND, and sa_mask.
+
+ // Re-enable signals again.
+ let control_flags = &Tcb::current().unwrap().os_specific.control.control_flags;
+ control_flags.store(control_flags.load(Ordering::Relaxed) & !SigcontrolFlags::INHIBIT_DELIVERY.bits(), Ordering::Release);
+ core::sync::atomic::compiler_fence(Ordering::Acquire);
+
let _ = syscall::write(1, b"INNER SIGNAL HANDLER\n");
- loop {}
+ /*loop {}
let handler: extern "C" fn(c_int) = core::mem::transmute(stack.sa_handler);
- handler(stack.sig_num as c_int)
+ handler(stack.sig_num as c_int)*/
}
#[cfg(not(target_arch = "x86"))]
pub(crate) unsafe extern "C" fn inner_c(stack: usize) {
--
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