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[PATCH] uml: S390 preparation, peekusr/pokeusr defined by subarch
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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 <[email protected]>
Signed-off-by: Jeff Dike <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Bodo Stroesser authored and Linus Torvalds committed May 7, 2005
1 parent 16c1116 commit 82c1c11
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Showing 4 changed files with 153 additions and 50 deletions.
79 changes: 29 additions & 50 deletions arch/um/kernel/ptrace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -67,6 +82,10 @@ long sys_ptrace(long request, long pid, long addr, long data)
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;
Expand All @@ -87,28 +106,9 @@ long sys_ptrace(long request, long pid, long addr, long data)
}

/* 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. */
Expand All @@ -121,35 +121,16 @@ long sys_ptrace(long request, long pid, long addr, long data)
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. */
ret = -EIO;
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);
}
Expand All @@ -172,8 +153,7 @@ long sys_ptrace(long request, long pid, long addr, long data)
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;
Expand All @@ -184,8 +164,7 @@ long sys_ptrace(long request, long pid, long addr, long data)
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);
Expand Down
40 changes: 40 additions & 0 deletions arch/um/sys-i386/ptrace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -73,6 +73,25 @@ int putreg(struct task_struct *child, int regno, unsigned long value)
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;
Expand All @@ -93,6 +112,27 @@ unsigned long getreg(struct task_struct *child, int regno)
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;
Expand Down
40 changes: 40 additions & 0 deletions arch/um/sys-ppc/ptrace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,25 @@ int putreg(struct task_struct *child, unsigned long regno,
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;
Expand All @@ -16,6 +35,27 @@ unsigned long getreg(struct task_struct *child, unsigned long regno)
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
Expand Down
44 changes: 44 additions & 0 deletions arch/um/sys-x86_64/ptrace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,27 @@ int putreg(struct task_struct *child, int regno, unsigned long value)
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;
Expand All @@ -84,6 +105,29 @@ unsigned long getreg(struct task_struct *child, int regno)
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
Expand Down

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