- fix-broken-vm86-interrupt-signal-handling.patch removed from -mm tree

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The patch titled

     fix broken vm86 interrupt/signal handling

has been removed from the -mm tree.  Its filename is

     fix-broken-vm86-interrupt-signal-handling.patch

This patch was dropped because it was nacked by the maintainer

------------------------------------------------------
Subject: fix broken vm86 interrupt/signal handling
From: "Aleksey Gorelov" <Aleksey_Gorelov@xxxxxxxxxxx>


This patch:

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c3ff8ec31c1249d268cd11390649768a12bec1b9

has broken vm86 interrupt/signal handling in case when vm86 is called from
kernel space.

In this scenario, if signal is pending because of vm86 interrupt,
do_notify_resume/do_signal exits immediately due to user_mode() check,
without processing any signals.  Thus, resume_userspace handler is spinning
in a tight loop with signal pending and TIF_SIGPENDING is set.  Previously
everything worked Ok.

The following patch fixes the issue

Signed-off-by: Aleksey Gorelov <aleksey_gorelov@xxxxxxxxxxx>
Cc: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---

 arch/i386/kernel/entry.S |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff -puN arch/i386/kernel/entry.S~fix-broken-vm86-interrupt-signal-handling arch/i386/kernel/entry.S
--- a/arch/i386/kernel/entry.S~fix-broken-vm86-interrupt-signal-handling
+++ a/arch/i386/kernel/entry.S
@@ -82,6 +82,12 @@ VM_MASK		= 0x00020000
 #define resume_kernel		restore_nocheck
 #endif
 
+#ifdef CONFIG_VM86
+#define resume_userspace_sig	check_userspace
+#else
+#define resume_userspace_sig	resume_userspace
+#endif
+
 #define SAVE_ALL \
 	cld; \
 	pushl %es; \
@@ -143,6 +149,7 @@ ret_from_exception:
 	preempt_stop
 ret_from_intr:
 	GET_THREAD_INFO(%ebp)
+check_userspace:
 	movl EFLAGS(%esp), %eax		# mix EFLAGS and CS
 	movb CS(%esp), %al
 	testl $(VM_MASK | 3), %eax
@@ -323,7 +330,7 @@ work_notifysig:				# deal with pending s
 					# vm86-space
 	xorl %edx, %edx
 	call do_notify_resume
-	jmp resume_userspace
+	jmp resume_userspace_sig
 
 	ALIGN
 work_notifysig_v86:
@@ -334,7 +341,7 @@ work_notifysig_v86:
 	movl %eax, %esp
 	xorl %edx, %edx
 	call do_notify_resume
-	jmp resume_userspace
+	jmp resume_userspace_sig
 #endif
 
 	# perform syscall exit tracing
_

Patches currently in -mm which might be from Aleksey_Gorelov@xxxxxxxxxxx are

fix-broken-vm86-interrupt-signal-handling.patch

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