[PATCH 4/12] UML - S390 preparation, peekusr/pokeusr defined by subarch

From: Jeff Dike
Date: Fri May 06 2005 - 17:58:02 EST

From: Bodo Stroesser <bstroesser@xxxxxxxxxxxxxxxxxxx>

s390 needs to change some parts of arch/um/kernel/ptrace.c.
Thus, the code regarding PEEKUSER and POKEUSER are shifted
to arch/um/sys-<subarch>/ptrace.c.
Also s390 debug registers need to be updated, when
singlestepping is switched on / off. Thus, setting/resetting
of singlestepping is centralized in the new function
set_singlestep(), which also inserts the macro
SUBARCH_SET_SINGLESTEP(mode), if defined.
Finally, s390 has the "ieee_instruction_pointer" in its
registers, which also is allowed to be read via
ptrace( PTRACE_PEEKUSER, getpid(), PT_IEEE_IP, 0);
To implement this feature, sys_ptrace inserts the macro
SUBARCH_PTRACE_SPECIAL, if defined.

Signed-off-by: Bodo Stroesser <bstroesser@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxx>

Index: linux-2.6.12-rc3-mm/arch/um/kernel/ptrace.c
===================================================================
--- linux-2.6.12-rc3-mm.orig/arch/um/kernel/ptrace.c 2005-05-06 14:36:28.000000000 -0400
+++ linux-2.6.12-rc3-mm/arch/um/kernel/ptrace.c 2005-05-06 14:44:04.000000000 -0400
@@ -19,15 +19,30 @@
#include "skas_ptrace.h"
#include "sysdep/ptrace.h"

+static inline void set_singlestepping(struct task_struct *child, int on)
+{
+ if (on)
+ child->ptrace |= PT_DTRACE;
+ else
+ child->ptrace &= ~PT_DTRACE;
+ child->thread.singlestep_syscall = 0;
+
+#ifdef SUBARCH_SET_SINGLESTEPPING
+ SUBARCH_SET_SINGLESTEPPING(child, on)
+#endif
+ }
+
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
- child->ptrace &= ~PT_DTRACE;
- child->thread.singlestep_syscall = 0;
+ set_singlestepping(child,0);
}

+extern int peek_user(struct task_struct * child, long addr, long data);
+extern int poke_user(struct task_struct * child, long addr, long data);
+
long sys_ptrace(long request, long pid, long addr, long data)
{
struct task_struct *child;
@@ -67,6 +82,10 @@
goto out_tsk;
}

+#ifdef SUBACH_PTRACE_SPECIAL
+ SUBARCH_PTRACE_SPECIAL(child,request,addr,data)
+#endif
+
ret = ptrace_check_attach(child, request == PTRACE_KILL);
if (ret < 0)
goto out_tsk;
@@ -87,28 +106,9 @@
}

/* read the word at location addr in the USER area. */
- case PTRACE_PEEKUSR: {
- unsigned long tmp;
-
- ret = -EIO;
- if ((addr & 3) || addr < 0)
- break;
-
- tmp = 0; /* Default return condition */
- if(addr < MAX_REG_OFFSET){
- tmp = getreg(child, addr);
- }
-#if defined(CONFIG_UML_X86) && !defined(CONFIG_64BIT)
- else if((addr >= offsetof(struct user, u_debugreg[0])) &&
- (addr <= offsetof(struct user, u_debugreg[7]))){
- addr -= offsetof(struct user, u_debugreg[0]);
- addr = addr >> 2;
- tmp = child->thread.arch.debugregs[addr];
- }
-#endif
- ret = put_user(tmp, (unsigned long __user *) data);
- break;
- }
+ case PTRACE_PEEKUSR:
+ ret = peek_user(child, addr, data);
+ break;

/* when I and D space are separate, this will have to be fixed. */
case PTRACE_POKETEXT: /* write the word at location addr. */
@@ -121,26 +121,8 @@
break;

case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
- ret = -EIO;
- if ((addr & 3) || addr < 0)
- break;
-
- if (addr < MAX_REG_OFFSET) {
- ret = putreg(child, addr, data);
- break;
- }
-#if defined(CONFIG_UML_X86) && !defined(CONFIG_64BIT)
- else if((addr >= offsetof(struct user, u_debugreg[0])) &&
- (addr <= offsetof(struct user, u_debugreg[7]))){
- addr -= offsetof(struct user, u_debugreg[0]);
- addr = addr >> 2;
- if((addr == 4) || (addr == 5)) break;
- child->thread.arch.debugregs[addr] = data;
- ret = 0;
- }
-#endif
-
- break;
+ ret = poke_user(child, addr, data);
+ break;

case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: { /* restart after signal. */
@@ -148,8 +130,7 @@
if (!valid_signal(data))
break;

- child->ptrace &= ~PT_DTRACE;
- child->thread.singlestep_syscall = 0;
+ set_singlestepping(child, 0);
if (request == PTRACE_SYSCALL) {
set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}
@@ -172,8 +153,7 @@
if (child->exit_state == EXIT_ZOMBIE) /* already dead */
break;

- child->ptrace &= ~PT_DTRACE;
- child->thread.singlestep_syscall = 0;
+ set_singlestepping(child, 0);
child->exit_code = SIGKILL;
wake_up_process(child);
break;
@@ -184,8 +164,7 @@
if (!valid_signal(data))
break;
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
- child->ptrace |= PT_DTRACE;
- child->thread.singlestep_syscall = 0;
+ set_singlestepping(child, 1);
child->exit_code = data;
/* give it a chance to run. */
wake_up_process(child);
Index: linux-2.6.12-rc3-mm/arch/um/sys-i386/ptrace.c
===================================================================
--- linux-2.6.12-rc3-mm.orig/arch/um/sys-i386/ptrace.c 2005-05-06 14:36:28.000000000 -0400
+++ linux-2.6.12-rc3-mm/arch/um/sys-i386/ptrace.c 2005-05-06 14:44:45.000000000 -0400
@@ -73,6 +73,25 @@
return 0;
}

+int poke_user(struct task_struct *child, long addr, long data)
+{
+ if ((addr & 3) || addr < 0)
+ return -EIO;
+
+ if (addr < MAX_REG_OFFSET)
+ return putreg(child, addr, data);
+
+ else if((addr >= offsetof(struct user, u_debugreg[0])) &&
+ (addr <= offsetof(struct user, u_debugreg[7]))){
+ addr -= offsetof(struct user, u_debugreg[0]);
+ addr = addr >> 2;
+ if((addr == 4) || (addr == 5)) return -EIO;
+ child->thread.arch.debugregs[addr] = data;
+ return 0;
+ }
+ return -EIO;
+}
+
unsigned long getreg(struct task_struct *child, int regno)
{
unsigned long retval = ~0UL;
@@ -93,6 +112,27 @@
return retval;
}

+int peek_user(struct task_struct *child, long addr, long data)
+{
+/* read the word at location addr in the USER area. */
+ unsigned long tmp;
+
+ if ((addr & 3) || addr < 0)
+ return -EIO;
+
+ tmp = 0; /* Default return condition */
+ if(addr < MAX_REG_OFFSET){
+ tmp = getreg(child, addr);
+ }
+ else if((addr >= offsetof(struct user, u_debugreg[0])) &&
+ (addr <= offsetof(struct user, u_debugreg[7]))){
+ addr -= offsetof(struct user, u_debugreg[0]);
+ addr = addr >> 2;
+ tmp = child->thread.arch.debugregs[addr];
+ }
+ return put_user(tmp, (unsigned long *) data);
+}
+
struct i387_fxsave_struct {
unsigned short cwd;
unsigned short swd;
Index: linux-2.6.12-rc3-mm/arch/um/sys-ppc/ptrace.c
===================================================================
--- linux-2.6.12-rc3-mm.orig/arch/um/sys-ppc/ptrace.c 2005-05-06 14:36:28.000000000 -0400
+++ linux-2.6.12-rc3-mm/arch/um/sys-ppc/ptrace.c 2005-05-06 14:41:25.000000000 -0400
@@ -8,6 +8,25 @@
return 0;
}

+int poke_user(struct task_struct *child, long addr, long data)
+{
+ if ((addr & 3) || addr < 0)
+ return -EIO;
+
+ if (addr < MAX_REG_OFFSET)
+ return putreg(child, addr, data);
+
+ else if((addr >= offsetof(struct user, u_debugreg[0])) &&
+ (addr <= offsetof(struct user, u_debugreg[7]))){
+ addr -= offsetof(struct user, u_debugreg[0]);
+ addr = addr >> 2;
+ if((addr == 4) || (addr == 5)) return -EIO;
+ child->thread.arch.debugregs[addr] = data;
+ return 0;
+ }
+ return -EIO;
+}
+
unsigned long getreg(struct task_struct *child, unsigned long regno)
{
unsigned long retval = ~0UL;
@@ -16,6 +35,27 @@
return retval;
}

+int peek_user(struct task_struct *child, long addr, long data)
+{
+ /* read the word at location addr in the USER area. */
+ unsigned long tmp;
+
+ if ((addr & 3) || addr < 0)
+ return -EIO;
+
+ tmp = 0; /* Default return condition */
+ if(addr < MAX_REG_OFFSET){
+ tmp = getreg(child, addr);
+ }
+ else if((addr >= offsetof(struct user, u_debugreg[0])) &&
+ (addr <= offsetof(struct user, u_debugreg[7]))){
+ addr -= offsetof(struct user, u_debugreg[0]);
+ addr = addr >> 2;
+ tmp = child->thread.arch.debugregs[addr];
+ }
+ return put_user(tmp, (unsigned long *) data);
+}
+
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
Index: linux-2.6.12-rc3-mm/arch/um/sys-x86_64/ptrace.c
===================================================================
--- linux-2.6.12-rc3-mm.orig/arch/um/sys-x86_64/ptrace.c 2005-05-06 14:36:28.000000000 -0400
+++ linux-2.6.12-rc3-mm/arch/um/sys-x86_64/ptrace.c 2005-05-06 14:46:00.000000000 -0400
@@ -62,6 +62,27 @@
return 0;
}

+int poke_user(struct task_struct *child, long addr, long data)
+{
+ if ((addr & 3) || addr < 0)
+ return -EIO;
+
+ if (addr < MAX_REG_OFFSET)
+ return putreg(child, addr, data);
+
+#if 0 /* Need x86_64 debugregs handling */
+ else if((addr >= offsetof(struct user, u_debugreg[0])) &&
+ (addr <= offsetof(struct user, u_debugreg[7]))){
+ addr -= offsetof(struct user, u_debugreg[0]);
+ addr = addr >> 2;
+ if((addr == 4) || (addr == 5)) return -EIO;
+ child->thread.arch.debugregs[addr] = data;
+ return 0;
+ }
+#endif
+ return -EIO;
+}
+
unsigned long getreg(struct task_struct *child, int regno)
{
unsigned long retval = ~0UL;
@@ -84,6 +105,29 @@
return retval;
}

+int peek_user(struct task_struct *child, long addr, long data)
+{
+ /* read the word at location addr in the USER area. */
+ unsigned long tmp;
+
+ if ((addr & 3) || addr < 0)
+ return -EIO;
+
+ tmp = 0; /* Default return condition */
+ if(addr < MAX_REG_OFFSET){
+ tmp = getreg(child, addr);
+ }
+#if 0 /* Need x86_64 debugregs handling */
+ else if((addr >= offsetof(struct user, u_debugreg[0])) &&
+ (addr <= offsetof(struct user, u_debugreg[7]))){
+ addr -= offsetof(struct user, u_debugreg[0]);
+ addr = addr >> 2;
+ tmp = child->thread.arch.debugregs[addr];
+ }
+#endif
+ return put_user(tmp, (unsigned long *) data);
+}
+
void arch_switch(void)
{
/* XXX

-
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