2009-03-10 21:45:24

by Renzo Davoli

[permalink] [raw]
Subject: [PATCH 1/2] ptrace_vm: ptrace for syscall emulation virtual machines

This patch adds the new PTRACE_VM_SKIPCALL and PTRACE_VM_SKIPEXIT
tags for ptrace's addr parameter.
In this way it is possible to (eventually) get rid of PTRACE_SYSEMU
PTRACE_SYSEMU_SINGLESTEP, while providing not only the same features
but a more general support for Virtual Machines.
Part#1: tracehook based architecture independent support

renzo

Signed-off-by: Renzo Davoli <[email protected]>
---
diff -Naur linux-2.6.29-rc7-umluml/include/linux/ptrace.h linux-2.6.29-rc7-vm1/include/linux/ptrace.h
--- linux-2.6.29-rc7-umluml/include/linux/ptrace.h 2009-03-06 20:26:13.000000000 +0100
+++ linux-2.6.29-rc7-vm1/include/linux/ptrace.h 2009-03-06 20:31:11.000000000 +0100
@@ -46,6 +46,11 @@
#define PTRACE_EVENT_VFORK_DONE 5
#define PTRACE_EVENT_EXIT 6

+/* options for new PTRACE_SYSCALL syntax*/
+#define PTRACE_SYSCALL_SKIPEXIT 0x2
+#define PTRACE_SYSCALL_SKIPCALL 0x6
+#define PTRACE_SYSCALL_MASK 0x00000006
+
#include <asm/ptrace.h>

#ifdef __KERNEL__
@@ -68,6 +73,10 @@
#define PT_TRACE_VFORK_DONE 0x00000100
#define PT_TRACE_EXIT 0x00000200

+#define PT_SYSCALL_SKIPEXIT 0x60000000
+#define PT_SYSCALL_SKIPCALL 0x40000000
+#define PT_SYSCALL_MASK 0x60000000
+
#define PT_TRACE_MASK 0x000003f4

/* single stepping state bits (used on ARM and PA-RISC) */
diff -Naur linux-2.6.29-rc7-umluml/include/linux/tracehook.h linux-2.6.29-rc7-vm1/include/linux/tracehook.h
--- linux-2.6.29-rc7-umluml/include/linux/tracehook.h 2009-03-06 20:26:13.000000000 +0100
+++ linux-2.6.29-rc7-vm1/include/linux/tracehook.h 2009-03-06 20:31:11.000000000 +0100
@@ -112,7 +112,7 @@
struct pt_regs *regs)
{
ptrace_report_syscall(regs);
- return 0;
+ return (task_ptrace(current) & PT_SYSCALL_SKIPCALL)?1:0;
}

/**
@@ -134,7 +134,8 @@
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
- ptrace_report_syscall(regs);
+ if (!(task_ptrace(current) & PT_SYSCALL_SKIPEXIT))
+ ptrace_report_syscall(regs);
}

/**
diff -Naur linux-2.6.29-rc7-umluml/kernel/ptrace.c linux-2.6.29-rc7-vm1/kernel/ptrace.c
--- linux-2.6.29-rc7-umluml/kernel/ptrace.c 2009-03-06 20:26:15.000000000 +0100
+++ linux-2.6.29-rc7-vm1/kernel/ptrace.c 2009-03-06 20:31:11.000000000 +0100
@@ -396,7 +396,7 @@
#define is_sysemu_singlestep(request) 0
#endif

-static int ptrace_resume(struct task_struct *child, long request, long data)
+static int ptrace_resume(struct task_struct *child, long request, long addr, long data)
{
if (!valid_signal(data))
return -EIO;
@@ -425,6 +425,9 @@
else
user_disable_single_step(child);

+ child->ptrace &= ~PT_SYSCALL_MASK;
+ child->ptrace |= (addr & PTRACE_SYSCALL_MASK) << 28;
+
child->exit_code = data;
wake_up_process(child);

@@ -486,12 +489,12 @@
#endif
case PTRACE_SYSCALL:
case PTRACE_CONT:
- return ptrace_resume(child, request, data);
+ return ptrace_resume(child, request, addr, data);

case PTRACE_KILL:
if (child->exit_state) /* already dead */
return 0;
- return ptrace_resume(child, request, SIGKILL);
+ return ptrace_resume(child, request, addr, SIGKILL);

default:
break;


2009-03-11 13:41:19

by Renzo Davoli

[permalink] [raw]
Subject: Re: [PATCH 1/2] ptrace_vm: ptrace for syscall emulation virtual machines

I am re-submitting the two patches. Now they should be (more)
consistent with the Coding Style specifications.

This patch adds the new PTRACE_VM_SKIPCALL and PTRACE_VM_SKIPEXIT
tags for ptrace's addr parameter.
In this way it is possible to (eventually) get rid of PTRACE_SYSEMU
PTRACE_SYSEMU_SINGLESTEP, while providing not only the same features
but a more general support for Virtual Machines.
Part#1: tracehook based architecture independent support

renzo

Signed-off-by: Renzo Davoli <[email protected]>
---
diff -Naur linux-2.6.29-rc7-umluml/include/linux/ptrace.h linux-2.6.29-rc7-vm1/include/linux/ptrace.h
--- linux-2.6.29-rc7-umluml/include/linux/ptrace.h 2009-03-06 20:26:13.000000000 +0100
+++ linux-2.6.29-rc7-vm1/include/linux/ptrace.h 2009-03-06 20:31:11.000000000 +0100
@@ -46,6 +46,11 @@
#define PTRACE_EVENT_VFORK_DONE 5
#define PTRACE_EVENT_EXIT 6

+/* options for new PTRACE_SYSCALL syntax*/
+#define PTRACE_SYSCALL_SKIPEXIT 0x2
+#define PTRACE_SYSCALL_SKIPCALL 0x6
+#define PTRACE_SYSCALL_MASK 0x00000006
+
#include <asm/ptrace.h>

#ifdef __KERNEL__
@@ -68,6 +73,10 @@
#define PT_TRACE_VFORK_DONE 0x00000100
#define PT_TRACE_EXIT 0x00000200

+#define PT_SYSCALL_SKIPEXIT 0x60000000
+#define PT_SYSCALL_SKIPCALL 0x40000000
+#define PT_SYSCALL_MASK 0x60000000
+
#define PT_TRACE_MASK 0x000003f4

/* single stepping state bits (used on ARM and PA-RISC) */
diff -Naur linux-2.6.29-rc7-umluml/include/linux/tracehook.h linux-2.6.29-rc7-vm1/include/linux/tracehook.h
--- linux-2.6.29-rc7-umluml/include/linux/tracehook.h 2009-03-06 20:26:13.000000000 +0100
+++ linux-2.6.29-rc7-vm1/include/linux/tracehook.h 2009-03-06 20:31:11.000000000 +0100
@@ -112,7 +112,7 @@
struct pt_regs *regs)
{
ptrace_report_syscall(regs);
- return 0;
+ return (task_ptrace(current) & PT_SYSCALL_SKIPCALL) ? 1 : 0;
}

/**
@@ -134,7 +134,8 @@
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
- ptrace_report_syscall(regs);
+ if (!(task_ptrace(current) & PT_SYSCALL_SKIPEXIT))
+ ptrace_report_syscall(regs);
}

/**
diff -Naur linux-2.6.29-rc7-umluml/kernel/ptrace.c linux-2.6.29-rc7-vm1/kernel/ptrace.c
--- linux-2.6.29-rc7-umluml/kernel/ptrace.c 2009-03-06 20:26:15.000000000 +0100
+++ linux-2.6.29-rc7-vm1/kernel/ptrace.c 2009-03-06 20:31:11.000000000 +0100
@@ -396,7 +396,7 @@
#define is_sysemu_singlestep(request) 0
#endif

-static int ptrace_resume(struct task_struct *child, long request, long data)
+static int ptrace_resume(struct task_struct *child, long request, long addr, long data)
{
if (!valid_signal(data))
return -EIO;
@@ -425,6 +425,9 @@
else
user_disable_single_step(child);

+ child->ptrace &= ~PT_SYSCALL_MASK;
+ child->ptrace |= (addr & PTRACE_SYSCALL_MASK) << 28;
+
child->exit_code = data;
wake_up_process(child);

@@ -486,12 +489,12 @@
#endif
case PTRACE_SYSCALL:
case PTRACE_CONT:
- return ptrace_resume(child, request, data);
+ return ptrace_resume(child, request, addr, data);

case PTRACE_KILL:
if (child->exit_state) /* already dead */
return 0;
- return ptrace_resume(child, request, SIGKILL);
+ return ptrace_resume(child, request, addr, SIGKILL);

default:
break;

2009-03-16 07:50:56

by Cong Wang

[permalink] [raw]
Subject: Re: [PATCH 1/2] ptrace_vm: ptrace for syscall emulation virtual machines

On Wed, Mar 11, 2009 at 02:41:03PM +0100, Renzo Davoli wrote:
>I am re-submitting the two patches. Now they should be (more)
>consistent with the Coding Style specifications.
>
>This patch adds the new PTRACE_VM_SKIPCALL and PTRACE_VM_SKIPEXIT
>tags for ptrace's addr parameter.
>In this way it is possible to (eventually) get rid of PTRACE_SYSEMU
>PTRACE_SYSEMU_SINGLESTEP, while providing not only the same features
>but a more general support for Virtual Machines.
>Part#1: tracehook based architecture independent support
>
>renzo
>
>Signed-off-by: Renzo Davoli <[email protected]>
>---
>diff -Naur linux-2.6.29-rc7-umluml/include/linux/ptrace.h linux-2.6.29-rc7-vm1/include/linux/ptrace.h
>--- linux-2.6.29-rc7-umluml/include/linux/ptrace.h 2009-03-06 20:26:13.000000000 +0100
>+++ linux-2.6.29-rc7-vm1/include/linux/ptrace.h 2009-03-06 20:31:11.000000000 +0100
>@@ -46,6 +46,11 @@
> #define PTRACE_EVENT_VFORK_DONE 5
> #define PTRACE_EVENT_EXIT 6
>
>+/* options for new PTRACE_SYSCALL syntax*/
>+#define PTRACE_SYSCALL_SKIPEXIT 0x2
>+#define PTRACE_SYSCALL_SKIPCALL 0x6
>+#define PTRACE_SYSCALL_MASK 0x00000006
>+
> #include <asm/ptrace.h>
>
> #ifdef __KERNEL__
>@@ -68,6 +73,10 @@
> #define PT_TRACE_VFORK_DONE 0x00000100
> #define PT_TRACE_EXIT 0x00000200
>
>+#define PT_SYSCALL_SKIPEXIT 0x60000000
>+#define PT_SYSCALL_SKIPCALL 0x40000000
>+#define PT_SYSCALL_MASK 0x60000000
>+
> #define PT_TRACE_MASK 0x000003f4
>
> /* single stepping state bits (used on ARM and PA-RISC) */
>diff -Naur linux-2.6.29-rc7-umluml/include/linux/tracehook.h linux-2.6.29-rc7-vm1/include/linux/tracehook.h
>--- linux-2.6.29-rc7-umluml/include/linux/tracehook.h 2009-03-06 20:26:13.000000000 +0100
>+++ linux-2.6.29-rc7-vm1/include/linux/tracehook.h 2009-03-06 20:31:11.000000000 +0100
>@@ -112,7 +112,7 @@
> struct pt_regs *regs)
> {
> ptrace_report_syscall(regs);
>- return 0;
>+ return (task_ptrace(current) & PT_SYSCALL_SKIPCALL) ? 1 : 0;
> }
>
> /**
>@@ -134,7 +134,8 @@
> */
> static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
> {
>- ptrace_report_syscall(regs);
>+ if (!(task_ptrace(current) & PT_SYSCALL_SKIPEXIT))
>+ ptrace_report_syscall(regs);
> }
>
> /**
>diff -Naur linux-2.6.29-rc7-umluml/kernel/ptrace.c linux-2.6.29-rc7-vm1/kernel/ptrace.c
>--- linux-2.6.29-rc7-umluml/kernel/ptrace.c 2009-03-06 20:26:15.000000000 +0100
>+++ linux-2.6.29-rc7-vm1/kernel/ptrace.c 2009-03-06 20:31:11.000000000 +0100
>@@ -396,7 +396,7 @@
> #define is_sysemu_singlestep(request) 0
> #endif
>
>-static int ptrace_resume(struct task_struct *child, long request, long data)
>+static int ptrace_resume(struct task_struct *child, long request, long addr, long data)

This line is longer than 80-characters, please break it into two lines.


> {
> if (!valid_signal(data))
> return -EIO;
>@@ -425,6 +425,9 @@
> else
> user_disable_single_step(child);
>
>+ child->ptrace &= ~PT_SYSCALL_MASK;
>+ child->ptrace |= (addr & PTRACE_SYSCALL_MASK) << 28;


Please don't use magic numbers, use a macro to define it.


>+
> child->exit_code = data;
> wake_up_process(child);
>
>@@ -486,12 +489,12 @@
> #endif
> case PTRACE_SYSCALL:
> case PTRACE_CONT:
>- return ptrace_resume(child, request, data);
>+ return ptrace_resume(child, request, addr, data);
>
> case PTRACE_KILL:
> if (child->exit_state) /* already dead */
> return 0;
>- return ptrace_resume(child, request, SIGKILL);
>+ return ptrace_resume(child, request, addr, SIGKILL);
>
> default:
> break;

--
Do what you love, f**k the rest! F**k the regulations!

2009-03-24 23:20:13

by Renzo Davoli

[permalink] [raw]
Subject: Re: [PATCH 1/2] ptrace_vm: ptrace for syscall emulation virtual machines

patch #1. Rebased on 2.6.29 and Cong's objections fixed.

renzo

Signed-off-by: Renzo Davoli <[email protected]>
---
diff -Naur linux-2.6.29/include/linux/ptrace.h linux-2.6.29-vm/include/linux/ptrace.h
--- linux-2.6.29/include/linux/ptrace.h 2009-03-24 00:12:14.000000000 +0100
+++ linux-2.6.29-vm/include/linux/ptrace.h 2009-03-24 22:10:23.000000000 +0100
@@ -46,6 +46,11 @@
#define PTRACE_EVENT_VFORK_DONE 5
#define PTRACE_EVENT_EXIT 6

+/* options for new PTRACE_SYSCALL syntax*/
+#define PTRACE_SYSCALL_SKIPEXIT 0x2
+#define PTRACE_SYSCALL_SKIPCALL 0x6
+#define PTRACE_SYSCALL_MASK 0x00000006
+
#include <asm/ptrace.h>

#ifdef __KERNEL__
@@ -68,6 +73,11 @@
#define PT_TRACE_VFORK_DONE 0x00000100
#define PT_TRACE_EXIT 0x00000200

+#define PT_SYSCALL_SKIPEXIT 0x60000000
+#define PT_SYSCALL_SKIPCALL 0x40000000
+#define PT_SYSCALL_MASK 0x60000000
+#define PTRACE2PT_SYSCALL(X) (((X) & PTRACE_SYSCALL_MASK) << 28)
+
#define PT_TRACE_MASK 0x000003f4

/* single stepping state bits (used on ARM and PA-RISC) */
diff -Naur linux-2.6.29/include/linux/tracehook.h linux-2.6.29-vm/include/linux/tracehook.h
--- linux-2.6.29/include/linux/tracehook.h 2009-03-24 00:12:14.000000000 +0100
+++ linux-2.6.29-vm/include/linux/tracehook.h 2009-03-24 22:04:39.000000000 +0100
@@ -112,7 +112,7 @@
struct pt_regs *regs)
{
ptrace_report_syscall(regs);
- return 0;
+ return (task_ptrace(current) & PT_SYSCALL_SKIPCALL) ? 1 : 0;
}

/**
@@ -134,7 +134,8 @@
*/
static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step)
{
- ptrace_report_syscall(regs);
+ if (!(task_ptrace(current) & PT_SYSCALL_SKIPEXIT))
+ ptrace_report_syscall(regs);
}

/**
diff -Naur linux-2.6.29/kernel/ptrace.c linux-2.6.29-vm/kernel/ptrace.c
--- linux-2.6.29/kernel/ptrace.c 2009-03-24 00:12:14.000000000 +0100
+++ linux-2.6.29-vm/kernel/ptrace.c 2009-03-24 22:09:46.000000000 +0100
@@ -396,7 +396,8 @@
#define is_sysemu_singlestep(request) 0
#endif

-static int ptrace_resume(struct task_struct *child, long request, long data)
+static int ptrace_resume(struct task_struct *child, long request,
+ long addr, long data)
{
if (!valid_signal(data))
return -EIO;
@@ -425,6 +426,9 @@
else
user_disable_single_step(child);

+ child->ptrace &= ~PT_SYSCALL_MASK;
+ child->ptrace |= PTRACE2PT_SYSCALL(addr);
+
child->exit_code = data;
wake_up_process(child);

@@ -486,12 +490,12 @@
#endif
case PTRACE_SYSCALL:
case PTRACE_CONT:
- return ptrace_resume(child, request, data);
+ return ptrace_resume(child, request, addr, data);

case PTRACE_KILL:
if (child->exit_state) /* already dead */
return 0;
- return ptrace_resume(child, request, SIGKILL);
+ return ptrace_resume(child, request, addr, SIGKILL);

default:
break;