i386: convert hardware exception 7 to an interrupt gate

Handle no coprocessor exception with interrupt initially off.

device_not_available in entry_32.S calls either math_state_restore
or math_emulate. This patch adds an extra indirection to be
able to re-enable interrupts explicitly in traps_32.c

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 13 deletions

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 109792bc7cf..5a885855fc8 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -760,20 +760,9 @@ ENTRY(device_not_available)
         RING0_INT_FRAME
         pushl $-1                       # mark this as an int
         CFI_ADJUST_CFA_OFFSET 4
-        SAVE_ALL
-        GET_CR0_INTO_EAX
-        testl $0x4, %eax                # EM (math emulation bit)
-        jne device_not_available_emulate
-        preempt_stop(CLBR_ANY)
-        call math_state_restore
-        jmp ret_from_exception
-device_not_available_emulate:
-        pushl $0                        # temporary storage for ORIG_EIP
+        pushl $do_device_not_available
         CFI_ADJUST_CFA_OFFSET 4
-        call math_emulate
-        addl $4, %esp
-        CFI_ADJUST_CFA_OFFSET -4
-        jmp ret_from_exception
+        jmp error_code
         CFI_ENDPROC
 END(device_not_available)