From: Dmitry V. Levin <ldv@altlinux.org>
Date: Wed, 20 Sep 2017 00:15:02 +0000 (+0000)
Subject: ppc64: fix sigreturn parser for ppc personality
X-Git-Tag: v4.20~55
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=2d3a6978107504f06dcb03880fc79b9ed8555203;p=strace

ppc64: fix sigreturn parser for ppc personality

* linux/powerpc/arch_sigreturn.c (arch_sigreturn) [POWERPC64]: Rewrite.
---

diff --git a/linux/powerpc/arch_sigreturn.c b/linux/powerpc/arch_sigreturn.c
index 4f68648d..5a5ca3ae 100644
--- a/linux/powerpc/arch_sigreturn.c
+++ b/linux/powerpc/arch_sigreturn.c
@@ -1,27 +1,32 @@
 static void
 arch_sigreturn(struct tcb *tcp)
 {
-	unsigned long addr = ppc_regs.gpr[1];
-	struct sigcontext sc;
-
 	/* Skip dummy stack frame. */
+	const unsigned long addr = ppc_regs.gpr[1] + 64;
+
 #ifdef POWERPC64
-	if (current_personality == 0)
-		addr += 128;
-	else
+	/* The only sigreturn on ppc64 is compat_sys_sigreturn. */
+	typedef struct {
+		unsigned int _unused[4];
+		int signal;
+		unsigned int handler;
+		unsigned int oldmask;
+		/* all the rest is irrelevant */
+	} sigreturn_context;
+#else
+	typedef struct sigcontext sigreturn_context;
 #endif
-		addr += 64;
+
+	sigreturn_context sc;
 
 	if (umove(tcp, addr, &sc) < 0) {
 		tprintf("{mask=%#lx}", addr);
 	} else {
-		unsigned long mask[NSIG_BYTES / sizeof(long)];
-#ifdef POWERPC64
-		mask[0] = sc.oldmask | (sc._unused[3] << 32);
-#else
-		mask[0] = sc.oldmask;
-		mask[1] = sc._unused[3];
-#endif
+		const unsigned int mask[NSIG_BYTES / sizeof(int)] = {
+			sc.oldmask,
+			sc._unused[3]
+		};
+
 		tprintsigmask_addr("{mask=", mask);
 		tprints("}");
 	}