alpha: take a bunch of syscalls into osf_sys.c

New helper: current_thread_info().  Allows to do a bunch of odd syscalls
in C. While we are at it, there had never been a reason to do
osf_getpriority() in assembler.  We also get "namespace"-aware (read:
consistent with getuid(2), etc.) behaviour from getx?id() syscalls now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 54 insertions, 111 deletions

diff --git a/arch/alpha/include/asm/ptrace.h b/arch/alpha/include/asm/ptrace.h
index fd698a174f26..b87755a19554 100644
--- a/arch/alpha/include/asm/ptrace.h
+++ b/arch/alpha/include/asm/ptrace.h
@@ -76,7 +76,10 @@ struct switch_stack {
 #define task_pt_regs(task) \
   ((struct pt_regs *) (task_stack_page(task) + 2*PAGE_SIZE) - 1)
 
-#define force_successful_syscall_return() (task_pt_regs(current)->r0 = 0)
+#define current_pt_regs() \
+  ((struct pt_regs *) ((char *)current_thread_info() + 2*PAGE_SIZE) - 1)
+
+#define force_successful_syscall_return() (current_pt_regs()->r0 = 0)
 
 #endif
 
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index 6d159cee5f2f..22b0c4d414a7 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -797,115 +797,6 @@ sys_rt_sigreturn:
 .end sys_rt_sigreturn
 
         .align  4
-        .globl  sys_sethae
-        .ent    sys_sethae
-sys_sethae:
-        .prologue 0
-        stq     $16, 152($sp)
-        ret
-.end sys_sethae
-
-        .align  4
-        .globl  osf_getpriority
-        .ent    osf_getpriority
-osf_getpriority:
-        lda     $sp, -16($sp)
-        stq     $26, 0($sp)
-        .prologue 0
-
-        jsr     $26, sys_getpriority
-
-        ldq     $26, 0($sp)
-        blt     $0, 1f
-
-        /* Return value is the unbiased priority, i.e. 20 - prio.
-           This does result in negative return values, so signal
-           no error by writing into the R0 slot.  */
-        lda     $1, 20
-        stq     $31, 16($sp)
-        subl    $1, $0, $0
-        unop
-
-1:      lda     $sp, 16($sp)
-        ret
-.end osf_getpriority
-
-        .align  4
-        .globl  sys_getxuid
-        .ent    sys_getxuid
-sys_getxuid:
-        .prologue 0
-        ldq     $2, TI_TASK($8)
-        ldq     $3, TASK_CRED($2)
-        ldl     $0, CRED_UID($3)
-        ldl     $1, CRED_EUID($3)
-        stq     $1, 80($sp)
-        ret
-.end sys_getxuid
-
-        .align  4
-        .globl  sys_getxgid
-        .ent    sys_getxgid
-sys_getxgid:
-        .prologue 0
-        ldq     $2, TI_TASK($8)
-        ldq     $3, TASK_CRED($2)
-        ldl     $0, CRED_GID($3)
-        ldl     $1, CRED_EGID($3)
-        stq     $1, 80($sp)
-        ret
-.end sys_getxgid
-
-        .align  4
-        .globl  sys_getxpid
-        .ent    sys_getxpid
-sys_getxpid:
-        .prologue 0
-        ldq     $2, TI_TASK($8)
-
-        /* See linux/kernel/timer.c sys_getppid for discussion
-           about this loop.  */
-        ldq     $3, TASK_GROUP_LEADER($2)
-        ldq     $4, TASK_REAL_PARENT($3)
-        ldl     $0, TASK_TGID($2)
-1:      ldl     $1, TASK_TGID($4)
-#ifdef CONFIG_SMP
-        mov     $4, $5
-        mb
-        ldq     $3, TASK_GROUP_LEADER($2)
-        ldq     $4, TASK_REAL_PARENT($3)
-        cmpeq   $4, $5, $5
-        beq     $5, 1b
-#endif
-        stq     $1, 80($sp)
-        ret
-.end sys_getxpid
-
-        .align  4
-        .globl  sys_alpha_pipe
-        .ent    sys_alpha_pipe
-sys_alpha_pipe:
-        lda     $sp, -16($sp)
-        stq     $26, 0($sp)
-        .prologue 0
-
-        mov     $31, $17
-        lda     $16, 8($sp)
-        jsr     $26, do_pipe_flags
-
-        ldq     $26, 0($sp)
-        bne     $0, 1f
-
-        /* The return values are in $0 and $20.  */
-        ldl     $1, 12($sp)
-        ldl     $0, 8($sp)
-
-        stq     $1, 80+16($sp)
-1:      lda     $sp, 16($sp)
-        ret
-.end sys_alpha_pipe
-
-        .align  4
         .globl  sys_execve
         .ent    sys_execve
 sys_execve:
diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index 98a103621af6..bc1acdda7a5e 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -1404,3 +1404,52 @@ SYSCALL_DEFINE3(osf_writev, unsigned long, fd,
 }
 
 #endif
+
+SYSCALL_DEFINE2(osf_getpriority, int, which, int, who)
+{
+        int prio = sys_getpriority(which, who);
+        if (prio >= 0) {
+                /* Return value is the unbiased priority, i.e. 20 - prio.
+                   This does result in negative return values, so signal
+                   no error */
+                force_successful_syscall_return();
+                prio = 20 - prio;
+        }
+        return prio;
+}
+
+SYSCALL_DEFINE0(getxuid)
+{
+        current_pt_regs()->r20 = sys_geteuid();
+        return sys_getuid();
+}
+
+SYSCALL_DEFINE0(getxgid)
+{
+        current_pt_regs()->r20 = sys_getegid();
+        return sys_getgid();
+}
+
+SYSCALL_DEFINE0(getxpid)
+{
+        current_pt_regs()->r20 = sys_getppid();
+        return sys_getpid();
+}
+
+SYSCALL_DEFINE0(alpha_pipe)
+{
+        int fd[2];
+        int res = do_pipe_flags(fd, 0);
+        if (!res) {
+                /* The return values are in $0 and $20.  */
+                current_pt_regs()->r20 = fd[1];
+                res = fd[0];
+        }
+        return res;
+}
+
+SYSCALL_DEFINE1(sethae, unsigned long, val)
+{
+        current_pt_regs()->hae = val;
+        return 0;
+}
diff --git a/arch/alpha/kernel/systbls.S b/arch/alpha/kernel/systbls.S
index b64157c98e02..2ac6b45c3e00 100644
--- a/arch/alpha/kernel/systbls.S
+++ b/arch/alpha/kernel/systbls.S
@@ -111,7 +111,7 @@ sys_call_table:
         .quad sys_socket
         .quad sys_connect
         .quad sys_accept
-        .quad osf_getpriority                   /* 100 */
+        .quad sys_osf_getpriority                       /* 100 */
         .quad sys_send
         .quad sys_recv
         .quad sys_sigreturn