X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=arch%2Fpowerpc%2Fkernel%2Fsignal_64.c;h=2fe6fc64b614ef9d1b935a472487eaf161967fd9;hb=948e78c3fc9c799b3f9b6c683b83c665942e6bbe;hp=93ebfb6944b6e9ff5e9a49e1c6ae039f582857ca;hpb=6a274c08f2f4dfac7167bbd849621f3a2b55d424;p=safe%2Fjmp%2Flinux-2.6

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 93ebfb6..2fe6fc6 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -74,7 +74,8 @@ static const char fmt64[] = KERN_INFO \
  */
 
 static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
-		 int signr, sigset_t *set, unsigned long handler)
+		 int signr, sigset_t *set, unsigned long handler,
+		 int ctx_has_vsx_region)
 {
 	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
 	 * process never used altivec yet (MSR_VEC is zero in pt_regs of
@@ -121,8 +122,8 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 	 * then out to userspace.  Update v_regs to point after the
 	 * VMX data.
 	 */
-	if (current->thread.used_vsr) {
-		flush_vsx_to_thread(current);
+	if (current->thread.used_vsr && ctx_has_vsx_region) {
+		__giveup_vsx(current);
 		v_regs += ELF_NVRREG;
 		err |= copy_vsx_to_user(v_regs, current);
 		/* set MSR_VSX in the MSR value in the frame to
@@ -235,8 +236,6 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
 	else
 		for (i = 0; i < 32 ; i++)
 			current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
-
-#else
 #endif
 	return err;
 }
@@ -268,6 +267,13 @@ static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
 }
 
 /*
+ * Userspace code may pass a ucontext which doesn't include VSX added
+ * at the end.  We need to check for this case.
+ */
+#define UCONTEXTSIZEWITHOUTVSX \
+		(sizeof(struct ucontext) - 32*sizeof(long))
+
+/*
  * Handle {get,set,swap}_context operations
  */
 int sys_swapcontext(struct ucontext __user *old_ctx,
@@ -276,25 +282,42 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
 {
 	unsigned char tmp;
 	sigset_t set;
+	unsigned long new_msr = 0;
+	int ctx_has_vsx_region = 0;
 
-	/* Context size is for future use. Right now, we only make sure
-	 * we are passed something we understand
+	if (new_ctx &&
+	    get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
+		return -EFAULT;
+	/*
+	 * Check that the context is not smaller than the original
+	 * size (with VMX but without VSX)
+	 */
+	if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
+		return -EINVAL;
+	/*
+	 * If the new context state sets the MSR VSX bits but
+	 * it doesn't provide VSX state.
 	 */
-	if (ctx_size < sizeof(struct ucontext))
+	if ((ctx_size < sizeof(struct ucontext)) &&
+	    (new_msr & MSR_VSX))
 		return -EINVAL;
+	/* Does the context have enough room to store VSX data? */
+	if (ctx_size >= sizeof(struct ucontext))
+		ctx_has_vsx_region = 1;
 
 	if (old_ctx != NULL) {
-		if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
-		    || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0)
+		if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
+		    || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
+					ctx_has_vsx_region)
 		    || __copy_to_user(&old_ctx->uc_sigmask,
 				      &current->blocked, sizeof(sigset_t)))
 			return -EFAULT;
 	}
 	if (new_ctx == NULL)
 		return 0;
-	if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
+	if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
 	    || __get_user(tmp, (u8 __user *) new_ctx)
-	    || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
+	    || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
 		return -EFAULT;
 
 	/*
@@ -379,7 +402,7 @@ int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
 	unsigned long newsp = 0;
 	long err = 0;
 
-	frame = get_sigframe(ka, regs, sizeof(*frame));
+	frame = get_sigframe(ka, regs, sizeof(*frame), 0);
 	if (unlikely(frame == NULL))
 		goto badframe;
 
@@ -397,7 +420,7 @@ int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
 			  &frame->uc.uc_stack.ss_flags);
 	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
-				(unsigned long)ka->sa.sa_handler);
+				(unsigned long)ka->sa.sa_handler, 1);
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 	if (err)
 		goto badframe;