From 84cb9c519287d8bfeafbc060bd5cf4f25dfc9eb8 Mon Sep 17 00:00:00 2001
From: Andi Kleen <ak@suse.de>
Date: Sat, 17 Feb 2007 13:33:00 +0100
Subject: [PATCH] x86: Don't require the vDSO for handling a.out signals

x86: Don't require the vDSO for handling a.out signals

and in other strange binfmts. vDSO is not necessarily mapped there.

This fixes signals in a.out programs

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 arch/i386/kernel/signal.c      | 6 +++++-
 arch/x86_64/ia32/ia32_signal.c | 7 ++++++-
 fs/binfmt_elf.c                | 3 ++-
 include/linux/binfmts.h        | 1 +
 4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c
index 65d7620eaa09..f654505bf54d 100644
--- a/arch/i386/kernel/signal.c
+++ b/arch/i386/kernel/signal.c
@@ -21,6 +21,7 @@
 #include <linux/suspend.h>
 #include <linux/ptrace.h>
 #include <linux/elf.h>
+#include <linux/binfmts.h>
 #include <asm/processor.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
@@ -349,7 +350,10 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 			goto give_sigsegv;
 	}
 
-	restorer = (void *)VDSO_SYM(&__kernel_sigreturn);
+	if (current->binfmt->hasvdso)
+		restorer = (void *)VDSO_SYM(&__kernel_sigreturn);
+	else
+		restorer = (void *)&frame->retcode;
 	if (ka->sa.sa_flags & SA_RESTORER)
 		restorer = ka->sa.sa_restorer;
 
diff --git a/arch/x86_64/ia32/ia32_signal.c b/arch/x86_64/ia32/ia32_signal.c
index ff499ef2a1ba..c7beadf5be41 100644
--- a/arch/x86_64/ia32/ia32_signal.c
+++ b/arch/x86_64/ia32/ia32_signal.c
@@ -21,6 +21,7 @@
 #include <linux/stddef.h>
 #include <linux/personality.h>
 #include <linux/compat.h>
+#include <linux/binfmts.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 #include <asm/i387.h>
@@ -449,7 +450,11 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
 
 	/* Return stub is in 32bit vsyscall page */
 	{ 
-		void __user *restorer = VSYSCALL32_SIGRETURN; 
+		void __user *restorer;
+		if (current->binfmt->hasvdso)
+			restorer = VSYSCALL32_SIGRETURN;
+		else
+			restorer = (void *)&frame->retcode;
 		if (ka->sa.sa_flags & SA_RESTORER)
 			restorer = ka->sa.sa_restorer;       
 		err |= __put_user(ptr_to_compat(restorer), &frame->pretcode);
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 669dbe5b0317..51db1182b27e 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -76,7 +76,8 @@ static struct linux_binfmt elf_format = {
 		.load_binary	= load_elf_binary,
 		.load_shlib	= load_elf_library,
 		.core_dump	= elf_core_dump,
-		.min_coredump	= ELF_EXEC_PAGESIZE
+		.min_coredump	= ELF_EXEC_PAGESIZE,
+		.hasvdso	= 1
 };
 
 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index c1e82c514443..2d956cd566ae 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -59,6 +59,7 @@ struct linux_binfmt {
 	int (*load_shlib)(struct file *);
 	int (*core_dump)(long signr, struct pt_regs * regs, struct file * file);
 	unsigned long min_coredump;	/* minimal dump size */
+	int hasvdso;
 };
 
 extern int register_binfmt(struct linux_binfmt *);
-- 
2.39.5