From f7d9f4e21eec20533461127b3d5aa1b5bf9a619b Mon Sep 17 00:00:00 2001
From: 4lDO2 <4lDO2@protonmail.com>
Date: Sat, 20 Jul 2024 19:41:04 +0200
Subject: [PATCH] Fix infinite loop & spurious signals for i686.
---
redox-rt/src/arch/i686.rs | 26 +++++++++++++++++++++++---
1 file changed, 23 insertions(+), 3 deletions(-)
diff --git a/redox-rt/src/arch/i686.rs b/redox-rt/src/arch/i686.rs
index be0d9240..2efd8931 100644
--- a/redox-rt/src/arch/i686.rs
+++ b/redox-rt/src/arch/i686.rs
@@ -155,7 +155,7 @@ asmfunction!(__relibc_internal_sigentry: ["
// Try clearing the pending bit, otherwise retry if another thread did that first
lock btr [ecx + {pctl_word}], eax
- jc 1b
+ jnc 1b
jmp 2f
3:
// Read realtime thread and process signal word together
@@ -170,7 +170,7 @@ asmfunction!(__relibc_internal_sigentry: ["
jc 8f
lock btr [ecx + {pctl_word} + 4], eax
- jc 1b
+ jnc 1b
add eax, 32
jmp 2f
8:
@@ -238,7 +238,23 @@ __relibc_internal_sigentry_crit_first:
__relibc_internal_sigentry_crit_second:
jmp dword ptr gs:[{tcb_sa_off} + {sa_tmp_eip}]
7:
- ud2
+ mov eax, gs:[0]
+ lea esp, [eax + {tcb_sc_off} + {sc_saved_eflags}]
+ popfd
+
+ mov esp, gs:[{tcb_sa_off} + {sa_tmp_esp}]
+
+ mov eax, gs:[{tcb_sc_off} + {sc_saved_eip}]
+ mov gs:[{tcb_sa_off} + {sa_tmp_eip}], eax
+
+ mov eax, gs:[{tcb_sa_off} + {sa_tmp_eax}]
+ mov ecx, gs:[{tcb_sa_off} + {sa_tmp_ecx}]
+ mov edx, gs:[{tcb_sa_off} + {sa_tmp_edx}]
+
+ and dword ptr gs:[{tcb_sc_off} + {sc_control}], ~1
+ .globl __relibc_internal_sigentry_crit_third
+__relibc_internal_sigentry_crit_third:
+ jmp dword ptr gs:[{tcb_sa_off} + {sa_tmp_eip}]
"] <= [
inner = sym inner_fastcall,
sa_tmp_eip = const offset_of!(SigArea, tmp_eip),
@@ -249,6 +265,7 @@ __relibc_internal_sigentry_crit_second:
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_control = const offset_of!(Sigcontrol, control_flags),
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),
@@ -281,6 +298,7 @@ asmfunction!(__relibc_internal_rlct_clone_ret -> usize: ["
extern "C" {
fn __relibc_internal_sigentry_crit_first();
fn __relibc_internal_sigentry_crit_second();
+ fn __relibc_internal_sigentry_crit_third();
}
pub unsafe fn arch_pre(stack: &mut SigStack, area: &mut SigArea) {
if stack.regs.eip == __relibc_internal_sigentry_crit_first as usize {
@@ -289,6 +307,8 @@ pub unsafe fn arch_pre(stack: &mut SigStack, area: &mut SigArea) {
stack.regs.eip = stack_ptr.sub(1).read();
} else if stack.regs.eip == __relibc_internal_sigentry_crit_second as usize {
stack.regs.eip = area.tmp_eip;
+ } else if stack.regs.eip == __relibc_internal_sigentry_crit_third as usize {
+ stack.regs.eip = area.tmp_eip;
}
}
#[no_mangle]
--
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