10 files changed, 67 insertions, 67 deletions

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index efc6a958b71d..a866411a2fcc 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -136,52 +136,6 @@ asmlinkage long sys32_sigsuspend(int history0, int history1, old_sigset_t mask)
         return sigsuspend(&blocked);
 }
 
-asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *uss_ptr,
-                                  stack_ia32_t __user *uoss_ptr,
-                                  struct pt_regs *regs)
-{
-        stack_t uss, uoss;
-        int ret, err = 0;
-        mm_segment_t seg;
-
-        if (uss_ptr) {
-                u32 ptr;
-
-                memset(&uss, 0, sizeof(stack_t));
-                if (!access_ok(VERIFY_READ, uss_ptr, sizeof(stack_ia32_t)))
-                        return -EFAULT;
-
-                get_user_try {
-                        get_user_ex(ptr, &uss_ptr->ss_sp);
-                        get_user_ex(uss.ss_flags, &uss_ptr->ss_flags);
-                        get_user_ex(uss.ss_size, &uss_ptr->ss_size);
-                } get_user_catch(err);
-
-                if (err)
-                        return -EFAULT;
-                uss.ss_sp = compat_ptr(ptr);
-        }
-        seg = get_fs();
-        set_fs(KERNEL_DS);
-        ret = do_sigaltstack((stack_t __force __user *) (uss_ptr ? &uss : NULL),
-                             (stack_t __force __user *) &uoss, regs->sp);
-        set_fs(seg);
-        if (ret >= 0 && uoss_ptr)  {
-                if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(stack_ia32_t)))
-                        return -EFAULT;
-
-                put_user_try {
-                        put_user_ex(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp);
-                        put_user_ex(uoss.ss_flags, &uoss_ptr->ss_flags);
-                        put_user_ex(uoss.ss_size, &uoss_ptr->ss_size);
-                } put_user_catch(err);
-
-                if (err)
-                        ret = -EFAULT;
-        }
-        return ret;
-}
-
 /*
  * Do a signal return; undo the signal stack.
  */
@@ -292,7 +246,6 @@ asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
         struct rt_sigframe_ia32 __user *frame;
         sigset_t set;
         unsigned int ax;
-        struct pt_regs tregs;
 
         frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
 
@@ -306,8 +259,7 @@ asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs)
         if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
                 goto badframe;
 
-        tregs = *regs;
-        if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
+        if (compat_restore_altstack(&frame->uc.uc_stack))
                 goto badframe;
 
         return ax;
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 32e6f05ddaaa..102ff7cb3e41 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -464,7 +464,6 @@ GLOBAL(\label)
 
         PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn, %rdi
         PTREGSCALL stub32_sigreturn, sys32_sigreturn, %rdi
-        PTREGSCALL stub32_sigaltstack, sys32_sigaltstack, %rdx
         PTREGSCALL stub32_execve, compat_sys_execve, %rcx
         PTREGSCALL stub32_fork, sys_fork, %rdi
         PTREGSCALL stub32_vfork, sys_vfork, %rdi
diff --git a/arch/x86/include/asm/ia32.h b/arch/x86/include/asm/ia32.h
index e6232773ce49..4c6da2e4bb1d 100644
--- a/arch/x86/include/asm/ia32.h
+++ b/arch/x86/include/asm/ia32.h
@@ -29,16 +29,10 @@ struct old_sigaction32 {
         unsigned int sa_restorer;       /* Another 32 bit pointer */
 };
 
-typedef struct sigaltstack_ia32 {
-        unsigned int    ss_sp;
-        int             ss_flags;
-        unsigned int    ss_size;
-} stack_ia32_t;
-
 struct ucontext_ia32 {
         unsigned int      uc_flags;
         unsigned int      uc_link;
-        stack_ia32_t      uc_stack;
+        compat_stack_t    uc_stack;
         struct sigcontext_ia32 uc_mcontext;
         compat_sigset_t   uc_sigmask;   /* mask last for extensibility */
 };
@@ -46,7 +40,7 @@ struct ucontext_ia32 {
 struct ucontext_x32 {
         unsigned int      uc_flags;
         unsigned int      uc_link;
-        stack_ia32_t      uc_stack;
+        compat_stack_t    uc_stack;
         unsigned int      uc__pad0;     /* needed for alignment */
         struct sigcontext uc_mcontext;  /* the 64-bit sigcontext type */
         compat_sigset_t   uc_sigmask;   /* mask last for extensibility */
diff --git a/arch/x86/include/asm/sys_ia32.h b/arch/x86/include/asm/sys_ia32.h
index c76fae4d90be..31f61f96e0fb 100644
--- a/arch/x86/include/asm/sys_ia32.h
+++ b/arch/x86/include/asm/sys_ia32.h
@@ -69,8 +69,6 @@ asmlinkage long sys32_fallocate(int, int, unsigned,
 
 /* ia32/ia32_signal.c */
 asmlinkage long sys32_sigsuspend(int, int, old_sigset_t);
-asmlinkage long sys32_sigaltstack(const stack_ia32_t __user *,
-                                  stack_ia32_t __user *, struct pt_regs *);
 asmlinkage long sys32_sigreturn(struct pt_regs *);
 asmlinkage long sys32_rt_sigreturn(struct pt_regs *);
 
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 6e462019f195..86d81199bbde 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -912,8 +912,6 @@ ENTRY(stub_rt_sigreturn)
 END(stub_rt_sigreturn)
 
 #ifdef CONFIG_X86_X32_ABI
-        PTREGSCALL stub_x32_sigaltstack, sys32_sigaltstack, %rdx
-
 ENTRY(stub_x32_rt_sigreturn)
         CFI_STARTPROC
         addq $8, %rsp
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 16d065c23baf..b17ed37c61a2 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -857,7 +857,6 @@ asmlinkage long sys32_x32_rt_sigreturn(struct pt_regs *regs)
         struct rt_sigframe_x32 __user *frame;
         sigset_t set;
         unsigned long ax;
-        struct pt_regs tregs;
 
         frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
 
@@ -871,8 +870,7 @@ asmlinkage long sys32_x32_rt_sigreturn(struct pt_regs *regs)
         if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
                 goto badframe;
 
-        tregs = *regs;
-        if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
+        if (compat_restore_altstack(&frame->uc.uc_stack))
                 goto badframe;
 
         return ax;
diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl
index 62c7b222e45c..235226efaa7f 100644
--- a/arch/x86/syscalls/syscall_32.tbl
+++ b/arch/x86/syscalls/syscall_32.tbl
@@ -192,7 +192,7 @@
 183     i386    getcwd                  sys_getcwd
 184     i386    capget                  sys_capget
 185     i386    capset                  sys_capset
-186     i386    sigaltstack             sys_sigaltstack                 stub32_sigaltstack
+186     i386    sigaltstack             sys_sigaltstack                 compat_sys_sigaltstack
 187     i386    sendfile                sys_sendfile                    sys32_sendfile
 188     i386    getpmsg
 189     i386    putpmsg
diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index 6ffa7f9d005e..c68cbe7174e7 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -337,7 +337,7 @@
 522     x32     rt_sigpending           sys32_rt_sigpending
 523     x32     rt_sigtimedwait         compat_sys_rt_sigtimedwait
 524     x32     rt_sigqueueinfo         sys32_rt_sigqueueinfo
-525     x32     sigaltstack             stub_x32_sigaltstack
+525     x32     sigaltstack             compat_sys_sigaltstack
 526     x32     timer_create            compat_sys_timer_create
 527     x32     mq_notify               compat_sys_mq_notify
 528     x32     kexec_load              compat_sys_kexec_load
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 62bb76f91baf..cb5637e2ee2c 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -68,6 +68,16 @@
 #ifndef compat_user_stack_pointer
 #define compat_user_stack_pointer() current_user_stack_pointer()
 #endif
+#ifdef CONFIG_GENERIC_SIGALTSTACK
+#ifndef compat_sigaltstack      /* we'll need that for MIPS */
+typedef struct compat_sigaltstack {
+        compat_uptr_t                   ss_sp;
+        int                             ss_flags;
+        compat_size_t                   ss_size;
+} compat_stack_t;
+#endif
+#endif
+
 #define compat_jiffies_to_clock_t(x)    \
                 (((unsigned long)(x) * COMPAT_USER_HZ) / HZ)
 
@@ -632,6 +642,12 @@ asmlinkage ssize_t compat_sys_process_vm_writev(compat_pid_t pid,
 
 asmlinkage long compat_sys_sendfile(int out_fd, int in_fd,
                                     compat_off_t __user *offset, compat_size_t count);
+#ifdef CONFIG_GENERIC_SIGALTSTACK
+asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr,
+                                       compat_stack_t __user *uoss_ptr);
+
+int compat_restore_altstack(const compat_stack_t __user *uss);
+#endif
 
 #else
 
diff --git a/kernel/signal.c b/kernel/signal.c
index f05f4c4150d9..aee85bd76b8a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -31,6 +31,7 @@
 #include <linux/nsproxy.h>
 #include <linux/user_namespace.h>
 #include <linux/uprobes.h>
+#include <linux/compat.h>
 #define CREATE_TRACE_POINTS
 #include <trace/events/signal.h>
 
@@ -3116,6 +3117,50 @@ int restore_altstack(const stack_t __user *uss)
         return err == -EFAULT ? err : 0;
 }
 
+#ifdef CONFIG_COMPAT
+#ifdef CONFIG_GENERIC_SIGALTSTACK
+asmlinkage long compat_sys_sigaltstack(const compat_stack_t __user *uss_ptr,
+                                       compat_stack_t __user *uoss_ptr)
+{
+        stack_t uss, uoss;
+        int ret;
+        mm_segment_t seg;
+
+        if (uss_ptr) {
+                compat_stack_t uss32;
+
+                memset(&uss, 0, sizeof(stack_t));
+                if (copy_from_user(&uss32, uss_ptr, sizeof(compat_stack_t)))
+                        return -EFAULT;
+                uss.ss_sp = compat_ptr(uss32.ss_sp);
+                uss.ss_flags = uss32.ss_flags;
+                uss.ss_size = uss32.ss_size;
+        }
+        seg = get_fs();
+        set_fs(KERNEL_DS);
+        ret = do_sigaltstack((stack_t __force __user *) (uss_ptr ? &uss : NULL),
+                             (stack_t __force __user *) &uoss,
+                             compat_user_stack_pointer());
+        set_fs(seg);
+        if (ret >= 0 && uoss_ptr)  {
+                if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(compat_stack_t)) ||
+                    __put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
+                    __put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
+                    __put_user(uoss.ss_size, &uoss_ptr->ss_size))
+                        ret = -EFAULT;
+        }
+        return ret;
+}
+
+int compat_restore_altstack(const compat_stack_t __user *uss)
+{
+        int err = compat_sys_sigaltstack(uss, NULL);
+        /* squash all but -EFAULT for now */
+        return err == -EFAULT ? err : 0;
+}
+#endif
+#endif
+
 #ifdef __ARCH_WANT_SYS_SIGPENDING
 
 /**