Commit 6e6d74cf authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds

[PATCH] uml: x86_64 ptrace fixes

This patch fixes some missing ptrace bits on x86_64.  PTRACE_ARCH_PRCTL is
hooked up and implemented.  This required generalizing arch_prctl_skas
slightly to take a task_struct to modify.  Previously, it always operated on
current.

Reading and writing the debug registers is also enabled by un-ifdefing the
code that implements that.  It turns out that x86_64 is identical to i386, so
the same code can be used.
Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f355559c
......@@ -18,6 +18,7 @@
#include "kern_util.h"
#include "skas_ptrace.h"
#include "sysdep/ptrace.h"
#include "os.h"
static inline void set_singlestepping(struct task_struct *child, int on)
{
......@@ -240,6 +241,12 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
ret = 0;
break;
}
#endif
#ifdef PTRACE_ARCH_PRCTL
case PTRACE_ARCH_PRCTL:
/* XXX Calls ptrace on the host - needs some SMP thinking */
ret = arch_prctl_skas(child, data, (void *) addr);
break;
#endif
default:
ret = ptrace_request(child, request, addr, data);
......
......@@ -71,8 +71,6 @@ int poke_user(struct task_struct *child, long addr, long data)
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]);
......@@ -81,7 +79,6 @@ int poke_user(struct task_struct *child, long addr, long data)
child->thread.arch.debugregs[addr] = data;
return 0;
}
#endif
return -EIO;
}
......@@ -119,14 +116,12 @@ int peek_user(struct task_struct *child, long addr, long data)
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);
}
......
......@@ -59,18 +59,20 @@ static long arch_prctl_tt(int code, unsigned long addr)
#ifdef CONFIG_MODE_SKAS
static long arch_prctl_skas(int code, unsigned long __user *addr)
long arch_prctl_skas(struct task_struct *task, int code,
unsigned long __user *addr)
{
unsigned long *ptr = addr, tmp;
long ret;
int pid = current->mm->context.skas.id.u.pid;
int pid = task->mm->context.skas.id.u.pid;
/*
* With ARCH_SET_FS (and ARCH_SET_GS is treated similarly to
* be safe), we need to call arch_prctl on the host because
* setting %fs may result in something else happening (like a
* GDT being set instead). So, we let the host fiddle the
* registers and restore them afterwards.
* GDT or thread.fs being set instead). So, we let the host
* fiddle the registers and thread struct and restore the
* registers afterwards.
*
* So, the saved registers are stored to the process (this
* needed because a stub may have been the last thing to run),
......@@ -118,7 +120,7 @@ static long arch_prctl_skas(int code, unsigned long __user *addr)
long sys_arch_prctl(int code, unsigned long addr)
{
return CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, code,
return CHOOSE_MODE_PROC(arch_prctl_tt, arch_prctl_skas, current, code,
(unsigned long __user *) addr);
}
......@@ -141,6 +143,6 @@ void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
if(to->thread.arch.fs == 0)
return;
arch_prctl_skas(ARCH_SET_FS, (void __user *) to->thread.arch.fs);
arch_prctl_skas(to, ARCH_SET_FS, (void __user *) to->thread.arch.fs);
}
......@@ -84,4 +84,7 @@ static inline void arch_switch_to_tt(struct task_struct *from,
extern void arch_switch_to_skas(struct task_struct *from,
struct task_struct *to);
extern long arch_prctl_skas(struct task_struct *task, int code,
unsigned long __user *addr);
#endif
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