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From: Stas Sergeev <stsp@aknet.ru>
To: Andrew Morton <akpm@osdl.org>
Cc: Linux kernel <linux-kernel@vger.kernel.org>
Subject: [patch] kprobes: dont steal interrupts from vm86
Date: Tue, 09 Nov 2004 22:01:46 +0300	[thread overview]
Message-ID: <4191141A.5090202@aknet.ru> (raw)

[-- Attachment #1: Type: text/plain, Size: 319 bytes --]

Hello.

With kprobes enabled, vm86 doesn't feel
good. The problem is that kprobes steal
the interrupts (mainly int3 I think) from
it for no good reason.
The attached patch fixes the problem by
checking the VM flag where it makes sense.

Andrew, can this please be applied?

Signed-off-by: Stas Sergeev <stsp@aknet.ru>


[-- Attachment #2: kprb_vm86.diff --]
[-- Type: text/x-patch, Size: 2468 bytes --]

--- linux-2.6.10-rc1/arch/i386/kernel/traps.c	2004-11-09 12:59:20.000000000 +0300
+++ linux-2.6.10-rc1-kprb/linux/arch/i386/kernel/traps.c	2004-11-09 13:35:18.625427704 +0300
@@ -408,7 +408,8 @@
 #define DO_ERROR(trapnr, signr, str, name) \
 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 { \
-	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+	if (!(regs->eflags & VM_MASK) && \
+		notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
 						== NOTIFY_STOP) \
 		return; \
 	do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
@@ -422,7 +423,8 @@
 	info.si_errno = 0; \
 	info.si_code = sicode; \
 	info.si_addr = (void __user *)siaddr; \
-	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+	if (!(regs->eflags & VM_MASK) && \
+		notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
 						== NOTIFY_STOP) \
 		return; \
 	do_trap(trapnr, signr, str, 0, regs, error_code, &info); \
@@ -431,7 +433,8 @@
 #define DO_VM86_ERROR(trapnr, signr, str, name) \
 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 { \
-	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+	if (!(regs->eflags & VM_MASK) && \
+		notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
 						== NOTIFY_STOP) \
 		return; \
 	do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
@@ -445,7 +448,8 @@
 	info.si_errno = 0; \
 	info.si_code = sicode; \
 	info.si_addr = (void __user *)siaddr; \
-	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+	if (!(regs->eflags & VM_MASK) && \
+		notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
 						== NOTIFY_STOP) \
 		return; \
 	do_trap(trapnr, signr, str, 1, regs, error_code, &info); \
@@ -652,7 +656,8 @@
 #ifdef CONFIG_KPROBES
 asmlinkage int do_int3(struct pt_regs *regs, long error_code)
 {
-	if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
+	if (!(regs->eflags & VM_MASK) &&
+		notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
 			== NOTIFY_STOP)
 		return 1;
 	/* This is an interrupt gate, because kprobes wants interrupts
@@ -693,7 +698,8 @@
 
 	__asm__ __volatile__("movl %%db6,%0" : "=r" (condition));
 
-	if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
+	if (!(regs->eflags & VM_MASK) && 
+		notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
 					SIGTRAP) == NOTIFY_STOP)
 		return;
 	/* It's safe to allow irq's after DR6 has been saved */

             reply	other threads:[~2004-11-09 19:01 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-11-09 19:01 Stas Sergeev [this message]
     [not found] <20041109130407.6d7faf10.akpm@osdl.org>
2004-11-10 10:49 ` [patch] kprobes: dont steal interrupts from vm86 Prasanna S Panchamukhi
2004-11-10 18:53   ` Stas Sergeev
2004-11-17 13:15     ` Prasanna S Panchamukhi
2004-11-18 14:55       ` Stas Sergeev
2004-12-02 19:28       ` Stas Sergeev
2004-12-06 15:28         ` Prasanna S Panchamukhi
2004-12-04 18:09       ` Stas Sergeev
2004-12-07  5:53         ` Prasanna S Panchamukhi
2004-12-07 18:44           ` Stas Sergeev
2004-12-09 12:47             ` Prasanna S Panchamukhi
2004-12-09 19:28               ` Stas Sergeev
2005-01-07 11:37                 ` Prasanna S Panchamukhi
2005-01-07 12:59                   ` Andi Kleen
2005-01-13  8:10                     ` Prasanna S Panchamukhi
2005-01-07 22:44                   ` Stas Sergeev

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