From 35c9485701acf5cdd3bd2b14ab9ad3656518478c Mon Sep 17 00:00:00 2001
From: 4lDO2 <4lDO2@protonmail.com>
Date: Sat, 20 Jul 2024 13:01:30 +0200
Subject: [PATCH] WIP: Implement process signals for i686 trampoline.
---
redox-rt/src/arch/i686.rs | 47 ++++++++++++++++++++++++++++++++-------
redox-rt/src/signal.rs | 2 +-
2 files changed, 40 insertions(+), 9 deletions(-)
diff --git a/redox-rt/src/arch/i686.rs b/redox-rt/src/arch/i686.rs
index 4866571a..681f1a9e 100644
--- a/redox-rt/src/arch/i686.rs
+++ b/redox-rt/src/arch/i686.rs
@@ -19,7 +19,9 @@ pub struct SigArea {
pub tmp_eip: usize,
pub tmp_esp: usize,
pub tmp_eax: usize,
+ pub tmp_ecx: usize,
pub tmp_edx: usize,
+ pub pctl: usize, // TODO: reference pctl directly
pub disable_signals_depth: u64,
pub last_sig_was_restart: bool,
}
@@ -129,22 +131,47 @@ asmfunction!(__relibc_internal_sigentry: ["
mov gs:[{tcb_sa_off} + {sa_tmp_esp}], esp
mov gs:[{tcb_sa_off} + {sa_tmp_eax}], eax
mov gs:[{tcb_sa_off} + {sa_tmp_edx}], edx
+ mov gs:[{tcb_sa_off} + {sa_tmp_ecx}], ecx
+1:
+ // Read standard signal word - first for this thread
+ mov edx, gs:[{tcb_sc_off} + {sc_word} + 4]
+ mov eax, gs:[{tcb_sc_off} + {sc_word}]
+ and eax, edx
+ bsf eax, eax
+ jnz 9f
- // Read pending half of first signal. This can be done nonatomically wrt the mask bits, since
- // only this thread is allowed to modify the latter.
+ mov ecx, gs:[{tcb_sa_off} + {sa_pctl}]
- // Read first signal word
- mov eax, gs:[{tcb_sc_off} + {sc_word}]
- and eax, gs:[{tcb_sc_off} + {sc_word} + 4]
+ // Read standard signal word - for the process
+ mov eax, [ecx + {pctl_word}]
+ and eax, edx
+ jz 3f
bsf eax, eax
- jnz 2f
- // Read second signal word
+ // Try clearing the pending bit, otherwise retry if another thread did that first
+ lock btr [ecx + {pctl_word}], eax
+ jc 1b
+ jmp 2f
+3:
+ // Read realtime thread and process signal word together
+ mov edx, [ecx + {pctl_word} + 4]
mov eax, gs:[{tcb_sc_off} + {sc_word} + 8]
+ or eax, edx
and eax, gs:[{tcb_sc_off} + {sc_word} + 12]
+ jz 7f // spurious signal
bsf eax, eax
- jz 7f
+
+ bt edx, eax
+ jc 8f
+
+ lock btr [ecx + {pctl_word} + 4], eax
+ jc 1b
+ add eax, 32
+ jmp 2f
+8:
add eax, 32
+9:
+ add eax, 64
2:
and esp, -{STACK_ALIGN}
@@ -212,15 +239,18 @@ __relibc_internal_sigentry_crit_second:
sa_tmp_eip = const offset_of!(SigArea, tmp_eip),
sa_tmp_esp = const offset_of!(SigArea, tmp_esp),
sa_tmp_eax = const offset_of!(SigArea, tmp_eax),
+ sa_tmp_ecx = const offset_of!(SigArea, tmp_ecx),
sa_tmp_edx = const offset_of!(SigArea, tmp_edx),
sa_altstack_top = const offset_of!(SigArea, altstack_top),
sa_altstack_bottom = const offset_of!(SigArea, altstack_bottom),
+ sa_pctl = const offset_of!(SigArea, pctl),
sc_saved_eflags = const offset_of!(Sigcontrol, saved_archdep_reg),
sc_saved_eip = const offset_of!(Sigcontrol, saved_ip),
sc_word = const offset_of!(Sigcontrol, word),
tcb_sa_off = const offset_of!(crate::Tcb, os_specific) + offset_of!(RtSigarea, arch),
tcb_sc_off = const offset_of!(crate::Tcb, os_specific) + offset_of!(RtSigarea, control),
pctl_off_actions = const offset_of!(SigProcControl, actions),
+ pctl_word = const offset_of!(SigProcControl, actions),
pctl = sym PROC_CONTROL_STRUCT,
STACK_ALIGN = const 16,
]);
@@ -256,6 +286,7 @@ pub unsafe fn arch_pre(stack: &mut SigStack, area: &mut SigArea) {
stack.regs.eip = area.tmp_eip;
}
}
+#[no_mangle]
pub unsafe fn manually_enter_trampoline() {
let c = &crate::Tcb::current().unwrap().os_specific.control;
c.control_flags.store(
diff --git a/redox-rt/src/signal.rs b/redox-rt/src/signal.rs
index b07bda6b..dcc0592a 100644
--- a/redox-rt/src/signal.rs
+++ b/redox-rt/src/signal.rs
@@ -481,7 +481,7 @@ pub fn setup_sighandler(tcb: &RtTcb) {
arch.altstack_top = usize::MAX;
arch.altstack_bottom = 0;
// TODO
- #[cfg(target_arch = "aarch64")]
+ #[cfg(any(target_arch = "i686", target_arch = "aarch64"))]
{
arch.pctl = core::ptr::addr_of!(PROC_CONTROL_STRUCT) as usize;
}
--
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