sh: Initial ELF FDPIC support.

This adds initial support for ELF FDPIC on MMU-less SH, as per version
0.2 of the ABI definition at:

	http://www.codesourcery.com/public/docs/sh-fdpic/sh-fdpic-abi.txt

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 46 insertions, 2 deletions

diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index fddb547f3c2b..2bc72def5cf8 100644
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -241,6 +241,29 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		break;
 	}
 #endif
+#ifdef CONFIG_BINFMT_ELF_FDPIC
+	case PTRACE_GETFDPIC: {
+		unsigned long tmp = 0;
+
+		switch (addr) {
+		case PTRACE_GETFDPIC_EXEC:
+			tmp = child->mm->context.exec_fdpic_loadmap;
+			break;
+		case PTRACE_GETFDPIC_INTERP:
+			tmp = child->mm->context.interp_fdpic_loadmap;
+			break;
+		default:
+			break;
+		}
+
+		ret = 0;
+		if (put_user(tmp, (unsigned long *) data)) {
+			ret = -EFAULT;
+			break;
+		}
+		break;
+	}
+#endif
 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;
diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c
index f311551d9a05..46170a9a7221 100644
--- a/arch/sh/kernel/signal_32.c
+++ b/arch/sh/kernel/signal_32.c
@@ -33,6 +33,11 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
+struct fdpic_func_descriptor {
+	unsigned long	text;
+	unsigned long	GOT;
+};
+
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */
@@ -378,7 +383,15 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 	regs->regs[4] = signal; /* Arg for signal handler */
 	regs->regs[5] = 0;
 	regs->regs[6] = (unsigned long) &frame->sc;
-	regs->pc = (unsigned long) ka->sa.sa_handler;
+
+	if (current->personality & FDPIC_FUNCPTRS) {
+		struct fdpic_func_descriptor __user *funcptr =
+			(struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
+
+		__get_user(regs->pc, &funcptr->text);
+		__get_user(regs->regs[12], &funcptr->GOT);
+	} else
+		regs->pc = (unsigned long)ka->sa.sa_handler;
 
 	set_fs(USER_DS);
 
@@ -458,7 +471,15 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	regs->regs[4] = signal; /* Arg for signal handler */
 	regs->regs[5] = (unsigned long) &frame->info;
 	regs->regs[6] = (unsigned long) &frame->uc;
-	regs->pc = (unsigned long) ka->sa.sa_handler;
+
+	if (current->personality & FDPIC_FUNCPTRS) {
+		struct fdpic_func_descriptor __user *funcptr =
+			(struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
+
+		__get_user(regs->pc, &funcptr->text);
+		__get_user(regs->regs[12], &funcptr->GOT);
+	} else
+		regs->pc = (unsigned long)ka->sa.sa_handler;
 
 	set_fs(USER_DS);