[RFC -tip 4/4] x86: ia32_signal: use __{get|put}_user_ex exception handling framework

Hiroshi Shimamoto
2009-01-06T03:10:27Z

From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>

Impact: use new uaccess exception handling framework

Use __{get|put}_user_ex exception handling framework.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
arch/x86/ia32/ia32_signal.c | 220 +++++++++++++++++++++++++------------------
1 files changed, 127 insertions(+), 93 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index 9dabd00..9502a77 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -46,79 +46,88 @@ void signal_fault(struct pt_regs *regs, void __user *frame, char *where);

int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
- int err;
+ int err = 0;

if (!access_ok(VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
return -EFAULT;

+ __put_user_ex_try();
+
/* If you change siginfo_t structure, please make sure that
this code is fixed accordingly.
It should never copy any pad contained in the structure
to avoid security leaks, but must copy the generic
3 ints plus the relevant union member. */
- err = __put_user(from->si_signo, &to->si_signo);
- err |= __put_user(from->si_errno, &to->si_errno);
- err |= __put_user((short)from->si_code, &to->si_code);
+ __put_user_ex(from->si_signo, &to->si_signo);
+ __put_user_ex(from->si_errno, &to->si_errno);
+ __put_user_ex((short)from->si_code, &to->si_code);

if (from->si_code < 0) {
- err |= __put_user(from->si_pid, &to->si_pid);
- err |= __put_user(from->si_uid, &to->si_uid);
- err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
+ __put_user_ex(from->si_pid, &to->si_pid);
+ __put_user_ex(from->si_uid, &to->si_uid);
+ __put_user_ex(ptr_to_compat(from->si_ptr), &to->si_ptr);
} else {
/*
* First 32bits of unions are always present:
* si_pid === si_band === si_tid === si_addr(LS half)
*/
- err |= __put_user(from->_sifields._pad[0],
+ __put_user_ex(from->_sifields._pad[0],
&to->_sifields._pad[0]);
switch (from->si_code >> 16) {
case __SI_FAULT >> 16:
break;
case __SI_CHLD >> 16:
- err |= __put_user(from->si_utime, &to->si_utime);
- err |= __put_user(from->si_stime, &to->si_stime);
- err |= __put_user(from->si_status, &to->si_status);
+ __put_user_ex(from->si_utime, &to->si_utime);
+ __put_user_ex(from->si_stime, &to->si_stime);
+ __put_user_ex(from->si_status, &to->si_status);
/* FALL THROUGH */
default:
case __SI_KILL >> 16:
- err |= __put_user(from->si_uid, &to->si_uid);
+ __put_user_ex(from->si_uid, &to->si_uid);
break;
case __SI_POLL >> 16:
- err |= __put_user(from->si_fd, &to->si_fd);
+ __put_user_ex(from->si_fd, &to->si_fd);
break;
case __SI_TIMER >> 16:
- err |= __put_user(from->si_overrun, &to->si_overrun);
- err |= __put_user(ptr_to_compat(from->si_ptr),
+ __put_user_ex(from->si_overrun, &to->si_overrun);
+ __put_user_ex(ptr_to_compat(from->si_ptr),
&to->si_ptr);
break;
/* This is not generated by the kernel as of now. */
case __SI_RT >> 16:
case __SI_MESGQ >> 16:
- err |= __put_user(from->si_uid, &to->si_uid);
- err |= __put_user(from->si_int, &to->si_int);
+ __put_user_ex(from->si_uid, &to->si_uid);
+ __put_user_ex(from->si_int, &to->si_int);
break;
}
}
+
+ __put_user_ex_catch(&err);
+
return err;
}

int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
- int err;
+ int err = 0;
u32 ptr32;

if (!access_ok(VERIFY_READ, from, sizeof(compat_siginfo_t)))
return -EFAULT;

- err = __get_user(to->si_signo, &from->si_signo);
- err |= __get_user(to->si_errno, &from->si_errno);
- err |= __get_user(to->si_code, &from->si_code);
+ __get_user_ex_try();

- err |= __get_user(to->si_pid, &from->si_pid);
- err |= __get_user(to->si_uid, &from->si_uid);
- err |= __get_user(ptr32, &from->si_ptr);
+ __get_user_ex(to->si_signo, &from->si_signo);
+ __get_user_ex(to->si_errno, &from->si_errno);
+ __get_user_ex(to->si_code, &from->si_code);
+
+ __get_user_ex(to->si_pid, &from->si_pid);
+ __get_user_ex(to->si_uid, &from->si_uid);
+ __get_user_ex(ptr32, &from->si_ptr);
to->si_ptr = compat_ptr(ptr32);

+ __get_user_ex_catch(&err);
+
return err;
}

@@ -142,31 +151,41 @@ asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
struct pt_regs *regs)
{
stack_t uss, uoss;
- int ret;
+ int ret, err = 0;
mm_segment_t seg;

+
if (uss_ptr) {
u32 ptr;

memset(&uss, 0, sizeof(stack_t));
- if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)) ||
- __get_user(ptr, &uss_ptr->ss_sp) ||
- __get_user(uss.ss_flags, &uss_ptr->ss_flags) ||
- __get_user(uss.ss_size, &uss_ptr->ss_size))
+ if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)))
return -EFAULT;
+ __get_user_ex_try();
+ __get_user_ex(ptr, &uss_ptr->ss_sp);
+ __get_user_ex(uss.ss_flags, &uss_ptr->ss_flags);
+ __get_user_ex(uss.ss_size, &uss_ptr->ss_size);
uss.ss_sp = compat_ptr(ptr);
+ __get_user_ex_catch(&err);
+ if (err)
+ return -EFAULT;
}
seg = get_fs();
set_fs(KERNEL_DS);
ret = do_sigaltstack(uss_ptr ? &uss : NULL, &uoss, regs->sp);
set_fs(seg);
if (ret >= 0 && uoss_ptr) {
- if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)) ||
- __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
- __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
- __put_user(uoss.ss_size, &uoss_ptr->ss_size))
- ret = -EFAULT;
+ if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)))
+ return -EFAULT;
+ __put_user_ex_try();
+ __put_user_ex(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp);
+ __put_user_ex(uoss.ss_flags, &uoss_ptr->ss_flags);
+ __put_user_ex(uoss.ss_size, &uoss_ptr->ss_size);
+ __put_user_ex_catch(&ret);
+ if (err)
+ return -EFAULT;
}
+
return ret;
}

@@ -174,18 +193,18 @@ asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
* Do a signal return; undo the signal stack.
*/
#define COPY(x) { \
- err |= __get_user(regs->x, &sc->x); \
+ __get_user_ex(regs->x, &sc->x); \
}

#define COPY_SEG_CPL3(seg) { \
unsigned short tmp; \
- err |= __get_user(tmp, &sc->seg); \
+ __get_user_ex(tmp, &sc->seg); \
regs->seg = tmp | 3; \
}

#define RELOAD_SEG(seg) { \
unsigned int cur, pre; \
- err |= __get_user(pre, &sc->seg); \
+ __get_user_ex(pre, &sc->seg); \
savesegment(seg, cur); \
pre |= 3; \
if (pre != cur) \
@@ -203,6 +222,8 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;

+ __get_user_ex_try();
+
#if DEBUG_SIG
printk(KERN_DEBUG "SIG restore_sigcontext: "
"sc=%p err(%x) eip(%x) cs(%x) flg(%x)\n",
@@ -215,7 +236,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
* the handler, but does not clobber them at least in the
* normal case.
*/
- err |= __get_user(gs, &sc->gs);
+ __get_user_ex(gs, &sc->gs);
gs |= 3;
savesegment(gs, oldgs);
if (gs != oldgs)
@@ -232,16 +253,18 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
COPY_SEG_CPL3(cs);
COPY_SEG_CPL3(ss);

- err |= __get_user(tmpflags, &sc->flags);
+ __get_user_ex(tmpflags, &sc->flags);
regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
/* disable syscall checks */
regs->orig_ax = -1;

- err |= __get_user(tmp, &sc->fpstate);
+ __get_user_ex(tmp, &sc->fpstate);
buf = compat_ptr(tmp);
err |= restore_i387_xstate_ia32(buf);

- err |= __get_user(*pax, &sc->ax);
+ __get_user_ex(*pax, &sc->ax);
+
+ __get_user_ex_catch(&err);
return err;
}

@@ -319,36 +342,40 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
{
int tmp, err = 0;

+ __put_user_ex_try();
+
savesegment(gs, tmp);
- err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
+ __put_user_ex(tmp, (unsigned int __user *)&sc->gs);
savesegment(fs, tmp);
- err |= __put_user(tmp, (unsigned int __user *)&sc->fs);
+ __put_user_ex(tmp, (unsigned int __user *)&sc->fs);
savesegment(ds, tmp);
- err |= __put_user(tmp, (unsigned int __user *)&sc->ds);
+ __put_user_ex(tmp, (unsigned int __user *)&sc->ds);
savesegment(es, tmp);
- err |= __put_user(tmp, (unsigned int __user *)&sc->es);
-
- err |= __put_user(regs->di, &sc->di);
- err |= __put_user(regs->si, &sc->si);
- err |= __put_user(regs->bp, &sc->bp);
- err |= __put_user(regs->sp, &sc->sp);
- err |= __put_user(regs->bx, &sc->bx);
- err |= __put_user(regs->dx, &sc->dx);
- err |= __put_user(regs->cx, &sc->cx);
- err |= __put_user(regs->ax, &sc->ax);
- err |= __put_user(current->thread.trap_no, &sc->trapno);
- err |= __put_user(current->thread.error_code, &sc->err);
- err |= __put_user(regs->ip, &sc->ip);
- err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
- err |= __put_user(regs->flags, &sc->flags);
- err |= __put_user(regs->sp, &sc->sp_at_signal);
- err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
-
- err |= __put_user(ptr_to_compat(fpstate), &sc->fpstate);
+ __put_user_ex(tmp, (unsigned int __user *)&sc->es);
+
+ __put_user_ex(regs->di, &sc->di);
+ __put_user_ex(regs->si, &sc->si);
+ __put_user_ex(regs->bp, &sc->bp);
+ __put_user_ex(regs->sp, &sc->sp);
+ __put_user_ex(regs->bx, &sc->bx);
+ __put_user_ex(regs->dx, &sc->dx);
+ __put_user_ex(regs->cx, &sc->cx);
+ __put_user_ex(regs->ax, &sc->ax);
+ __put_user_ex(current->thread.trap_no, &sc->trapno);
+ __put_user_ex(current->thread.error_code, &sc->err);
+ __put_user_ex(regs->ip, &sc->ip);
+ __put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
+ __put_user_ex(regs->flags, &sc->flags);
+ __put_user_ex(regs->sp, &sc->sp_at_signal);
+ __put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
+
+ __put_user_ex(ptr_to_compat(fpstate), &sc->fpstate);

/* non-iBCS2 extensions.. */
- err |= __put_user(mask, &sc->oldmask);
- err |= __put_user(current->thread.cr2, &sc->cr2);
+ __put_user_ex(mask, &sc->oldmask);
+ __put_user_ex(current->thread.cr2, &sc->cr2);
+
+ __put_user_ex_catch(&err);

return err;
}
@@ -415,16 +442,19 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;

- if (__put_user(sig, &frame->sig))
- return -EFAULT;
+ __put_user_ex_try();

- if (ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
- return -EFAULT;
+ __put_user_ex(sig, &frame->sig);
+
+ err |= ia32_setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]);
+ if (err)
+ goto out;

if (_COMPAT_NSIG_WORDS > 1) {
- if (__copy_to_user(frame->extramask, &set->sig[1],
- sizeof(frame->extramask)))
- return -EFAULT;
+ err |= __copy_to_user(frame->extramask, &set->sig[1],
+ sizeof(frame->extramask));
+ if (err)
+ goto out;
}

if (ka->sa.sa_flags & SA_RESTORER) {
@@ -437,15 +467,13 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
else
restorer = &frame->retcode;
}
- err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
+ __put_user_ex(ptr_to_compat(restorer), &frame->pretcode);

/*
* These are actually not used anymore, but left because some
* gdb versions depend on them as a marker.
*/
- err |= __put_user(*((u64 *)&code), (u64 *)frame->retcode);
- if (err)
- return -EFAULT;
+ __put_user_ex(*((u64 *)&code), (u64 *)frame->retcode);

/* Set up registers for signal handler */
regs->sp = (unsigned long) frame;
@@ -467,7 +495,10 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
current->comm, current->pid, frame, regs->ip, frame->pretcode);
#endif

- return 0;
+out:
+ __put_user_ex_catch(&err);
+
+ return err;
}

int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
@@ -496,43 +527,43 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;

- err |= __put_user(sig, &frame->sig);
- err |= __put_user(ptr_to_compat(&frame->info), &frame->pinfo);
- err |= __put_user(ptr_to_compat(&frame->uc), &frame->puc);
+ __put_user_ex_try();
+
+ __put_user_ex(sig, &frame->sig);
+ __put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo);
+ __put_user_ex(ptr_to_compat(&frame->uc), &frame->puc);
err |= copy_siginfo_to_user32(&frame->info, info);
if (err)
- return -EFAULT;
+ goto out;

/* Create the ucontext. */
if (cpu_has_xsave)
- err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
+ __put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
else
- err |= __put_user(0, &frame->uc.uc_flags);
- err |= __put_user(0, &frame->uc.uc_link);
- err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
- err |= __put_user(sas_ss_flags(regs->sp),
+ __put_user_ex(0, &frame->uc.uc_flags);
+ __put_user_ex(0, &frame->uc.uc_link);
+ __put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+ __put_user_ex(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
- err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ __put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
- return -EFAULT;
+ goto out;

if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
else
restorer = VDSO32_SYMBOL(current->mm->context.vdso,
rt_sigreturn);
- err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
+ __put_user_ex(ptr_to_compat(restorer), &frame->pretcode);

/*
* Not actually used anymore, but left because some gdb
* versions need it.
*/
- err |= __put_user(*((u64 *)&code), (u64 *)frame->retcode);
- if (err)
- return -EFAULT;
+ __put_user_ex(*((u64 *)&code), (u64 *)frame->retcode);

/* Set up registers for signal handler */
regs->sp = (unsigned long) frame;
@@ -554,5 +585,8 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
current->comm, current->pid, frame, regs->ip, frame->pretcode);
#endif

- return 0;
+out:
+ __put_user_ex_catch(&err);
+
+ return err;
}
--
1.6.0.4