Module Name: src
Committed By: nonaka
Date: Fri Feb 24 12:24:25 UTC 2017
Modified Files:
src/sys/arch/i386/stand/efiboot/bootia32: startprog32.S
Log Message:
efiboot: Don't access old stack after copying a kernel.
It's possible that the old stack is overwritten by the kernel.
To generate a diff of this commit:
cvs rdiff -u -r1.1 -r1.2 \
src/sys/arch/i386/stand/efiboot/bootia32/startprog32.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/i386/stand/efiboot/bootia32/startprog32.S
diff -u src/sys/arch/i386/stand/efiboot/bootia32/startprog32.S:1.1 src/sys/arch/i386/stand/efiboot/bootia32/startprog32.S:1.2
--- src/sys/arch/i386/stand/efiboot/bootia32/startprog32.S:1.1 Tue Feb 21 10:53:37 2017
+++ src/sys/arch/i386/stand/efiboot/bootia32/startprog32.S Fri Feb 24 12:24:25 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: startprog32.S,v 1.1 2017/02/21 10:53:37 nonaka Exp $ */
+/* $NetBSD: startprog32.S,v 1.2 2017/02/24 12:24:25 nonaka Exp $ */
/* NetBSD: startprog.S,v 1.4 2016/12/04 08:21:08 maxv Exp */
/*
@@ -91,6 +91,9 @@ start:
cli
+ movl 8(%ebp), %ebx /* %ebx: entry address */
+ movl 36(%ebp), %edx /* %edx: loaded start address */
+
/* Prepare a new stack */
movl 20(%ebp), %eax /* stack */
subl $4, %eax
@@ -108,12 +111,12 @@ start:
rep
movsl /* copy %ds:(%esi) -> %es:(%edi) */
cld
- mov %edi, %edx /* %edx: new stack pointer */
+ mov %edi, %esp /* set new stack pointer */
/* Copy kernel */
- movl 24(%esp), %edi /* dest */
- movl 28(%esp), %esi /* src */
- movl 32(%esp), %ecx /* size */
+ movl 24(%ebp), %edi /* dest */
+ movl 28(%ebp), %esi /* src */
+ movl 32(%ebp), %ecx /* size */
#if defined(NO_OVERLAP)
movl %ecx, %eax
#else
@@ -179,20 +182,17 @@ start:
.Lcopy_done:
cld /* LynxOS depends on it */
- movl 8(%ebp), %esi /* %esi: entry address */
- movl 36(%ebp), %edi /* %edi: loaded start address */
-
/* Prepare jump address */
- lea (start32a - start)(%edi), %eax
- movl %eax, (start32r - start)(%edi)
+ lea (start32a - start)(%edx), %eax
+ movl %eax, (start32r - start)(%edx)
/* Setup GDT */
- lea (gdt - start)(%edi), %eax
- movl %eax, (gdtrr - start)(%edi)
- lgdt (gdtr - start)(%edi)
+ lea (gdt - start)(%edx), %eax
+ movl %eax, (gdtrr - start)(%edx)
+ lgdt (gdtr - start)(%edx)
/* Jump to set %cs */
- ljmp *(start32r - start)(%edi)
+ ljmp *(start32r - start)(%edx)
.align 4
start32a:
@@ -203,7 +203,8 @@ start32a:
movw %ax, %gs
movw %ax, %ss
- movl %edx, %esp
+ /* Already set new stack pointer */
+ movl %esp, %ebp
/* Disable Paging in CR0 */
movl %cr0, %eax
@@ -220,8 +221,8 @@ start32a:
.align 4
start32b:
xor %eax, %eax
- movl %esi, (start32r - start)(%edi)
- ljmp *(start32r - start)(%edi)
+ movl %ebx, (start32r - start)(%edx)
+ ljmp *(start32r - start)(%edx)
.align 16
start32r:
