kernel: fix overlapping interrupt / regular stacks

4 files changed, 11 insertions, 9 deletions

diff --git a/src/kernel/arch/i386/boot.s b/src/kernel/arch/i386/boot.s
index 24c076f..743c6d6 100644
--- a/src/kernel/arch/i386/boot.s
+++ b/src/kernel/arch/i386/boot.s
@@ -2,7 +2,7 @@
 .global _start
 .type _start, @function
 _start:
-	mov $_bss_end, %esp // the stack is at the top of bss
+	mov $_stack_top, %esp
 	call sysenter_setup
 	push %ebx // address of the Multiboot struct
 	call kmain_early
diff --git a/src/kernel/arch/i386/gdt/gdt.c b/src/kernel/arch/i386/gdt/gdt.c
index f016caa..3662bf6 100644
--- a/src/kernel/arch/i386/gdt/gdt.c
+++ b/src/kernel/arch/i386/gdt/gdt.c
@@ -4,7 +4,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-extern char _isr_stack_top;
+extern char _isr_mini_stack;
 
 struct gdt_entry {
 	uint64_t limit_low  : 16;
@@ -83,7 +83,7 @@ static void gdt_prepare(void) {
 	// tss
 	memset(&TSS, 0, sizeof(TSS));
 	TSS.ss0 = SEG_r0data << 3; // kernel data segment
-	TSS.esp0 = (uintptr_t) &_isr_stack_top;
+	TSS.esp0 = (uintptr_t) &_isr_mini_stack;
 
 	GDT[SEG_TSS] = (struct gdt_entry) {
 		.limit_low  = sizeof(TSS),
diff --git a/src/kernel/arch/i386/interrupts/isr_stub.s b/src/kernel/arch/i386/interrupts/isr_stub.s
index 9a903f6..c09d4b2 100644
--- a/src/kernel/arch/i386/interrupts/isr_stub.s
+++ b/src/kernel/arch/i386/interrupts/isr_stub.s
@@ -23,11 +23,11 @@ _isr_stage2:
 	mov %ebx, %cr0
 
 	mov %esp, %ebp
-	mov $_bss_end, %esp // switch to kernel stack
+	mov $_isr_big_stack, %esp
 	push %eax // push the vector nr
 	call isr_stage3
 
-	mov %ebp, %esp // switch back to isr_stack
+	mov %ebp, %esp
 	pop %eax // restore old cr0
 	mov %eax, %cr0
 
@@ -35,8 +35,7 @@ _isr_stage2:
 	iret
 
 .align 8
-_ist_stack_btm:
 // TODO overflow check
 .skip 64 // seems to be enough
-.global _isr_stack_top
-_isr_stack_top:
+.global _isr_mini_stack
+_isr_mini_stack:
diff --git a/src/kernel/linker.ld b/src/kernel/linker.ld
index 84945b1..371f2d7 100644
--- a/src/kernel/linker.ld
+++ b/src/kernel/linker.ld
@@ -30,8 +30,11 @@ SECTIONS
 		*(COMMON)
 		*(.bss)
 
-		_stack_bottom = .;
 		. += 16K;
+		_isr_big_stack = .;
+
+		. += 16K;
+		_stack_top = .;
 	}
 	_bss_end = (. + 0xFFF) & ~0xFFF; /* aligned to 4K */
 }