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authorBrian Gerst <brgerst@gmail.com>2015-07-29 01:41:19 -0400
committerIngo Molnar <mingo@kernel.org>2015-07-31 13:31:09 +0200
commit5ed92a8ab71f8865ba07811429c988c72299b315 (patch)
tree30e8cd33bd97ca0c0b7a835e11b6ab41657c7356 /arch/x86/include/asm/vm86.h
parent90c6085a248f8f964588617f51329688bcc9f2bc (diff)
x86/vm86: Use the normal pt_regs area for vm86
Change to use the normal pt_regs area to enter and exit vm86 mode. This is done by increasing the padding at the top of the stack to make room for the extra vm86 segment slots in the IRET frame. It then saves the 32-bit regs in the off-stack vm86 data, and copies in the vm86 regs. Exiting back to 32-bit mode does the reverse. This allows removing the hacks to jump directly into the exit asm code due to having to change the stack pointer. Returning normally from the vm86 syscall and the exception handlers allows things like ptrace and auditing to work properly. Signed-off-by: Brian Gerst <brgerst@gmail.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1438148483-11932-5-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/vm86.h')
-rw-r--r--arch/x86/include/asm/vm86.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/include/asm/vm86.h b/arch/x86/include/asm/vm86.h
index 226d6c157ebc..e45386eee17a 100644
--- a/arch/x86/include/asm/vm86.h
+++ b/arch/x86/include/asm/vm86.h
@@ -29,7 +29,7 @@ struct kernel_vm86_regs {
struct vm86 {
struct vm86plus_struct __user *vm86_info;
- struct pt_regs *regs32;
+ struct pt_regs regs32;
unsigned long v86flags;
unsigned long v86mask;
unsigned long saved_sp0;
@@ -46,7 +46,7 @@ struct vm86 {
void handle_vm86_fault(struct kernel_vm86_regs *, long);
int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
-struct pt_regs *save_v86_state(struct kernel_vm86_regs *);
+void save_v86_state(struct kernel_vm86_regs *, int);
struct task_struct;
void release_vm86_irqs(struct task_struct *);
@@ -69,6 +69,8 @@ static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c)
return 0;
}
+static inline void save_v86_state(struct kernel_vm86_regs *a, int b) { }
+
#define free_vm86(t) do { } while(0)
#endif /* CONFIG_VM86 */