[POWERPC] Merge creation of signal frame
The code for creating signal frames was still duplicated and split
in strange ways between 32 and 64 bits, including the SA_ONSTACK
handling being in do_signal on 32 bits but inside handle_rt_signal
on 64 bits etc...
This moves the 64 bits get_sigframe() to the generic signal.c,
cleans it a bit, moves the access_ok() call done by all callers to
it as well, and adapts/cleanups the 3 different signal handling cases
to use that common function.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 32481e7..590057e 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -282,14 +282,17 @@
/*
* When we have signals to deliver, we set up on the
* user stack, going down from the original stack pointer:
- * a sigregs struct
+ * an ABI gap of 56 words
+ * an mcontext struct
* a sigcontext struct
* a gap of __SIGNAL_FRAMESIZE bytes
*
- * Each of these things must be a multiple of 16 bytes in size.
+ * Each of these things must be a multiple of 16 bytes in size. The following
+ * structure represent all of this except the __SIGNAL_FRAMESIZE gap
*
*/
-struct sigregs {
+struct sigframe {
+ struct sigcontext sctx; /* the sigcontext */
struct mcontext mctx; /* all the register values */
/*
* Programs using the rs6000/xcoff abi can save up to 19 gp
@@ -698,21 +701,16 @@
*/
int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset,
- struct pt_regs *regs, unsigned long newsp)
+ struct pt_regs *regs)
{
struct rt_sigframe __user *rt_sf;
struct mcontext __user *frame;
- unsigned long origsp = newsp;
+ unsigned long newsp = 0;
/* Set up Signal Frame */
/* Put a Real Time Context onto stack */
- newsp -= sizeof(*rt_sf);
- rt_sf = (struct rt_sigframe __user *)newsp;
-
- /* create a stack frame for the caller of the handler */
- newsp -= __SIGNAL_FRAMESIZE + 16;
-
- if (!access_ok(VERIFY_WRITE, (void __user *)newsp, origsp - newsp))
+ rt_sf = get_sigframe(ka, regs, sizeof(*rt_sf));
+ if (unlikely(rt_sf == NULL))
goto badframe;
/* Put the siginfo & fill in most of the ucontext */
@@ -742,8 +740,12 @@
current->thread.fpscr.val = 0; /* turn off all fp exceptions */
+ /* create a stack frame for the caller of the handler */
+ newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
if (put_user(regs->gpr[1], (u32 __user *)newsp))
goto badframe;
+
+ /* Fill registers for signal handler */
regs->gpr[1] = newsp;
regs->gpr[3] = sig;
regs->gpr[4] = (unsigned long) &rt_sf->info;
@@ -988,26 +990,17 @@
* OK, we're invoking a handler
*/
int handle_signal32(unsigned long sig, struct k_sigaction *ka,
- siginfo_t *info, sigset_t *oldset, struct pt_regs *regs,
- unsigned long newsp)
+ siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
{
struct sigcontext __user *sc;
- struct sigregs __user *frame;
- unsigned long origsp = newsp;
+ struct sigframe __user *frame;
+ unsigned long newsp = 0;
/* Set up Signal Frame */
- newsp -= sizeof(struct sigregs);
- frame = (struct sigregs __user *) newsp;
-
- /* Put a sigcontext on the stack */
- newsp -= sizeof(*sc);
- sc = (struct sigcontext __user *) newsp;
-
- /* create a stack frame for the caller of the handler */
- newsp -= __SIGNAL_FRAMESIZE;
-
- if (!access_ok(VERIFY_WRITE, (void __user *) newsp, origsp - newsp))
+ frame = get_sigframe(ka, regs, sizeof(*frame));
+ if (unlikely(frame == NULL))
goto badframe;
+ sc = (struct sigcontext __user *) &frame->sctx;
#if _NSIG != 64
#error "Please adjust handle_signal()"
@@ -1019,7 +1012,7 @@
#else
|| __put_user(oldset->sig[1], &sc->_unused[3])
#endif
- || __put_user(to_user_ptr(frame), &sc->regs)
+ || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
|| __put_user(sig, &sc->signal))
goto badframe;
@@ -1035,8 +1028,11 @@
current->thread.fpscr.val = 0; /* turn off all fp exceptions */
+ /* create a stack frame for the caller of the handler */
+ newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
if (put_user(regs->gpr[1], (u32 __user *)newsp))
goto badframe;
+
regs->gpr[1] = newsp;
regs->gpr[3] = sig;
regs->gpr[4] = (unsigned long) sc;