Commit e16b2781 authored by Roland McGrath's avatar Roland McGrath Committed by Linus Torvalds

ptrace: compat_ptrace_request siginfo

This adds support for PTRACE_GETSIGINFO and PTRACE_SETSIGINFO in
compat_ptrace_request.  It relies on existing arch definitions for
copy_siginfo_to_user32 and copy_siginfo_from_user32.

On powerpc, this fixes a longstanding regression of 32-bit ptrace
calls on 64-bit kernels vs native calls (64-bit calls or 32-bit
kernels).  This can be seen in a 32-bit call using PTRACE_GETSIGINFO
to examine e.g. siginfo_t.si_addr from a signal that sets it.
(This was broken as of 2.6.24 and, I presume, many or all prior versions.)
Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 553a5672
...@@ -323,9 +323,8 @@ static int ptrace_setoptions(struct task_struct *child, long data) ...@@ -323,9 +323,8 @@ static int ptrace_setoptions(struct task_struct *child, long data)
return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
} }
static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
{ {
siginfo_t lastinfo;
int error = -ESRCH; int error = -ESRCH;
read_lock(&tasklist_lock); read_lock(&tasklist_lock);
...@@ -333,31 +332,25 @@ static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) ...@@ -333,31 +332,25 @@ static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data)
error = -EINVAL; error = -EINVAL;
spin_lock_irq(&child->sighand->siglock); spin_lock_irq(&child->sighand->siglock);
if (likely(child->last_siginfo != NULL)) { if (likely(child->last_siginfo != NULL)) {
lastinfo = *child->last_siginfo; *info = *child->last_siginfo;
error = 0; error = 0;
} }
spin_unlock_irq(&child->sighand->siglock); spin_unlock_irq(&child->sighand->siglock);
} }
read_unlock(&tasklist_lock); read_unlock(&tasklist_lock);
if (!error)
return copy_siginfo_to_user(data, &lastinfo);
return error; return error;
} }
static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) static int ptrace_setsiginfo(struct task_struct *child, const siginfo_t *info)
{ {
siginfo_t newinfo;
int error = -ESRCH; int error = -ESRCH;
if (copy_from_user(&newinfo, data, sizeof (siginfo_t)))
return -EFAULT;
read_lock(&tasklist_lock); read_lock(&tasklist_lock);
if (likely(child->sighand != NULL)) { if (likely(child->sighand != NULL)) {
error = -EINVAL; error = -EINVAL;
spin_lock_irq(&child->sighand->siglock); spin_lock_irq(&child->sighand->siglock);
if (likely(child->last_siginfo != NULL)) { if (likely(child->last_siginfo != NULL)) {
*child->last_siginfo = newinfo; *child->last_siginfo = *info;
error = 0; error = 0;
} }
spin_unlock_irq(&child->sighand->siglock); spin_unlock_irq(&child->sighand->siglock);
...@@ -424,6 +417,7 @@ int ptrace_request(struct task_struct *child, long request, ...@@ -424,6 +417,7 @@ int ptrace_request(struct task_struct *child, long request,
long addr, long data) long addr, long data)
{ {
int ret = -EIO; int ret = -EIO;
siginfo_t siginfo;
switch (request) { switch (request) {
case PTRACE_PEEKTEXT: case PTRACE_PEEKTEXT:
...@@ -442,12 +436,22 @@ int ptrace_request(struct task_struct *child, long request, ...@@ -442,12 +436,22 @@ int ptrace_request(struct task_struct *child, long request,
case PTRACE_GETEVENTMSG: case PTRACE_GETEVENTMSG:
ret = put_user(child->ptrace_message, (unsigned long __user *) data); ret = put_user(child->ptrace_message, (unsigned long __user *) data);
break; break;
case PTRACE_GETSIGINFO: case PTRACE_GETSIGINFO:
ret = ptrace_getsiginfo(child, (siginfo_t __user *) data); ret = ptrace_getsiginfo(child, &siginfo);
if (!ret)
ret = copy_siginfo_to_user((siginfo_t __user *) data,
&siginfo);
break; break;
case PTRACE_SETSIGINFO: case PTRACE_SETSIGINFO:
ret = ptrace_setsiginfo(child, (siginfo_t __user *) data); if (copy_from_user(&siginfo, (siginfo_t __user *) data,
sizeof siginfo))
ret = -EFAULT;
else
ret = ptrace_setsiginfo(child, &siginfo);
break; break;
case PTRACE_DETACH: /* detach a process that was attached. */ case PTRACE_DETACH: /* detach a process that was attached. */
ret = ptrace_detach(child, data); ret = ptrace_detach(child, data);
break; break;
...@@ -616,6 +620,7 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, ...@@ -616,6 +620,7 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request,
{ {
compat_ulong_t __user *datap = compat_ptr(data); compat_ulong_t __user *datap = compat_ptr(data);
compat_ulong_t word; compat_ulong_t word;
siginfo_t siginfo;
int ret; int ret;
switch (request) { switch (request) {
...@@ -638,6 +643,23 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, ...@@ -638,6 +643,23 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request,
ret = put_user((compat_ulong_t) child->ptrace_message, datap); ret = put_user((compat_ulong_t) child->ptrace_message, datap);
break; break;
case PTRACE_GETSIGINFO:
ret = ptrace_getsiginfo(child, &siginfo);
if (!ret)
ret = copy_siginfo_to_user32(
(struct compat_siginfo __user *) datap,
&siginfo);
break;
case PTRACE_SETSIGINFO:
memset(&siginfo, 0, sizeof siginfo);
if (copy_siginfo_from_user32(
&siginfo, (struct compat_siginfo __user *) datap))
ret = -EFAULT;
else
ret = ptrace_setsiginfo(child, &siginfo);
break;
default: default:
ret = ptrace_request(child, request, addr, data); ret = ptrace_request(child, request, addr, data);
} }
......
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