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

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

Signed-off-by: Andi Kleen <ak@suse.de>

4 files changed, 14 insertions, 3 deletions

diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c
index 8f4afcc7d2ab..4f99e870c986 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 490f7c1b7c84..359eacc38509 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 *);